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301. In most monocot angiosperms, the leaves typically show:
ⓐ. Reticulate venation with a prominent midrib and many net-like branches
ⓑ. Parallel venation where veins run more or less parallel along the lamina
ⓒ. Dichotomous venation with repeated forking of the mid-vein in the lamina
ⓓ. No venation, because monocot leaves rely only on diffusion for transport
Correct Answer: Parallel venation where veins run more or less parallel along the lamina
Explanation: Monocot leaves commonly exhibit parallel venation, in which the vascular strands run side-by-side from base to tip with limited net-like interconnections. This feature is strongly associated with the typical monocot leaf structure and is widely used as a field-level diagnostic character. Parallel venation supports efficient longitudinal transport along long, narrow leaves common in grasses and related groups. While exceptions can occur, the general pattern remains a key classification clue. Therefore, parallel venation is the characteristic venation pattern in most monocots.
302. A leaf showing net-like venation is most commonly associated with:
ⓐ. Monocots because their vascular bundles are scattered in the stem
ⓑ. Gymnosperms because cones require net venation for seed exposure
ⓒ. Fern sporophytes because sori occur in a net-like arrangement on fronds
ⓓ. Dicots because veins form a reticulate network across the lamina
Correct Answer: Dicots because veins form a reticulate network across the lamina
Explanation: Reticulate (net-like) venation is a typical feature of dicot leaves, where a midrib gives rise to secondary and tertiary veins forming an interconnected network. This network provides multiple pathways for conduction and strengthens the lamina against tearing. It is commonly used in basic classification to distinguish dicots from monocots, which more often show parallel venation. Although botanical exceptions exist, exam questions generally treat reticulate venation as a dicot marker. Hence, net-like venation most commonly indicates a dicot.
303. In a typical dicot stem, vascular bundles are usually:
ⓐ. Arranged in a ring, separating cortex on the outside and pith in the center
ⓑ. Scattered throughout the ground tissue with no clear ring formation
ⓒ. Restricted only to the outer epidermis as small vascular patches
ⓓ. Present only in roots because stems do not need conduction tissues
Correct Answer: Arranged in a ring, separating cortex on the outside and pith in the center
Explanation: Dicot stems generally show vascular bundles arranged in a ring, which creates a clear distinction between an outer cortex and an inner pith. This ring arrangement is closely linked with the presence of cambium between xylem and phloem in many dicots. It also supports organized radial transport and structural stability, which becomes important for thicker stems. The arrangement is therefore a key anatomical character used to identify dicot stems in sections. Hence, ring-arranged vascular bundles are typical of dicot stems.
304. A transverse section of a stem shows vascular bundles scattered in the ground tissue with no distinct ring. This most strongly indicates:
ⓐ. Dicot stem with active cambium forming secondary growth
ⓑ. Dicot root with radial bundles and exarch xylem
ⓒ. Monocot stem with scattered vascular bundles in ground tissue
ⓓ. Fern stem where bundles occur only near sori-bearing regions
Correct Answer: Monocot stem with scattered vascular bundles in ground tissue
Explanation: Monocot stems typically have vascular bundles scattered throughout the ground tissue rather than arranged in a neat ring. This scattered pattern is one of the most reliable anatomical features to distinguish monocot stems from dicot stems in practical identification. Because bundles are dispersed, monocot stems usually do not show a sharply separated cortex and pith like many dicots. This internal organization also correlates with common differences in cambium activity and secondary growth patterns. Therefore, scattered vascular bundles strongly indicate a monocot stem.
305. The vascular bundles in most monocot stems are commonly described as “closed” mainly because:
ⓐ. Phloem is completely absent, so conduction is only through xylem
ⓑ. Cambium is absent within the bundle, limiting secondary growth from that bundle
ⓒ. Xylem occurs outside phloem, forming an inverted arrangement
ⓓ. The bundle is covered by petals and sepals, keeping it enclosed like a flower
Correct Answer: Cambium is absent within the bundle, limiting secondary growth from that bundle
Explanation: In many monocot stems, vascular bundles do not contain a cambium layer between xylem and phloem, so they are termed “closed” bundles. Without cambium, the bundle cannot produce secondary xylem and secondary phloem in the typical way seen in many dicots. This is one key reason why many monocots do not undergo conventional secondary thickening. The feature is diagnostic in stem anatomy questions and ties directly to growth patterns. Hence, monocot bundles are called closed because cambium is absent within the bundle.
306. Reticulate venation in dicot leaves is best understood as:
ⓐ. A branching network of veins that distributes water/food and provides mechanical support
ⓑ. A set of equal parallel veins that run unbranched from base to apex
ⓒ. A pattern where veins appear only near the margins and not in the center
ⓓ. A venation pattern limited to flowers and never seen in leaves
Correct Answer: A branching network of veins that distributes water/food and provides mechanical support
Explanation: Reticulate venation forms an interconnected network of veins, providing multiple routes for transport across the leaf lamina. This redundancy helps maintain supply even if some minor veins are damaged and also strengthens the leaf against mechanical stress. In typical dicots, a midrib with branching secondary veins produces a net-like pattern visible on the lamina. This structural organization is therefore both functional (transport) and supportive (strengthening). Hence, reticulate venation is a branching vein network aiding conduction and mechanical support.
307. Which combination is most appropriate for a typical monocot plant based on leaf venation and stem vascular bundle arrangement?
ⓐ. Reticulate venation + vascular bundles arranged in a ring in the stem
ⓑ. Parallel venation + vascular bundles scattered in the stem ground tissue
ⓒ. Dichotomous venation + radial vascular bundles typical of roots
ⓓ. No venation + no vascular bundles because conduction occurs by diffusion
Correct Answer: Parallel venation + vascular bundles scattered in the stem ground tissue
Explanation: A typical monocot shows parallel venation in leaves and scattered vascular bundles in the stem when viewed in transverse section. These two characters are frequently paired in classification and practical identification because they reinforce each other across organs. Parallel venation reflects the common monocot leaf architecture, while scattered bundles reflect the common monocot stem anatomy. Although exceptions exist, this combination is the expected diagnostic pattern for monocots in standard exam biology. Therefore, parallel venation with scattered stem bundles best fits a typical monocot.
308. Which combination is most appropriate for a typical dicot plant based on leaf venation and stem vascular bundle arrangement?
ⓐ. Parallel venation + scattered bundles with no clear cortex and pith separation
ⓑ. Parallel venation + ring bundles with cambium always absent from the stem
ⓒ. Reticulate venation + vascular bundles arranged in a ring in the stem
ⓓ. Dichotomous venation + scattered bundles confined only to the outer cortex
Correct Answer: Reticulate venation + vascular bundles arranged in a ring in the stem
Explanation: Typical dicots show reticulate venation in leaves and ring-arranged vascular bundles in stems, which are key diagnostic characters used together. Reticulate venation reflects a net-like vein distribution across the lamina, and the stem anatomy commonly shows bundles in a ring with a distinct cortex and pith. This arrangement often supports cambium activity in many dicots, enabling secondary growth. The paired traits are therefore central to routine monocot–dicot comparisons. Hence, reticulate venation with ring-arranged stem bundles best fits a typical dicot.
309. A plant has parallel venation in leaves but the stem shows vascular bundles arranged in a ring. The best conclusion is:
ⓐ. It must be a fern because sori demand parallel venation in all leaves
ⓑ. It must be a gymnosperm because cones require ring bundles in stems
ⓒ. It must be a bryophyte because vascular bundles are absent in its stem
ⓓ. It may be an exception or special case, so multiple characters should be checked before final grouping
Correct Answer: It may be an exception or special case, so multiple characters should be checked before final grouping
Explanation: While parallel venation suggests monocot affinity and ring bundles suggest dicot affinity, individual characters can show exceptions in real plants. Reliable classification should use a combination of traits such as root type, flower parts, vascular bundle structure (open/closed), and other anatomical markers. Exam comparisons give “typical” patterns, but conceptual understanding requires recognizing that nature can show intermediate or unusual combinations. Therefore, the safest conclusion is to treat it as an exception and confirm using additional diagnostic characters. Hence, multiple characters should be checked before final grouping.
310. Which statement correctly links vascular bundle arrangement with secondary growth in many angiosperms?
ⓐ. Scattered closed bundles usually favor typical secondary growth through cambium in each bundle
ⓑ. Ring-arranged bundles with cambium commonly support secondary growth in many dicot stems
ⓒ. Reticulate venation directly causes secondary growth by forming cambium in leaves
ⓓ. Parallel venation prevents cambium formation in roots, so roots never thicken
Correct Answer: Ring-arranged bundles with cambium commonly support secondary growth in many dicot stems
Explanation: In many dicots, vascular bundles are arranged in a ring and contain cambium (open bundles), which can form a continuous cambial ring and produce secondary xylem and phloem. This cambial activity drives secondary growth, increasing stem girth and enabling woody habit in many species. In contrast, many monocots have scattered, closed bundles lacking cambium, so typical secondary thickening is usually absent. The key link is therefore the arrangement and presence of cambium, not venation alone. Hence, ring bundles with cambium commonly support secondary growth in many dicot stems.
311. In alternation of generations, the gametophyte generation is:
ⓐ. Haploid and produces gametes by mitosis
ⓑ. Diploid and produces gametes by meiosis
ⓒ. Haploid and produces spores by meiosis
ⓓ. Diploid and produces spores by mitosis
Correct Answer: Haploid and produces gametes by mitosis
Explanation: The gametophyte is the haploid phase of the life cycle, so it cannot perform meiosis to make gametes. Instead, it forms gametes by mitotic divisions within the antheridia and archegonia (or their equivalents). Meiosis is reserved for the diploid sporophyte to restore the haploid condition via spores. This alternating sequence maintains chromosome number stability across generations. Therefore, haploid gametophyte producing gametes by mitosis is the correct description.
312. The sporophyte generation in plants begins with the:
ⓐ. Spore that germinates to form a prothallus
ⓑ. Zygote formed after fertilisation
ⓒ. Gamete formed inside antheridium or archegonium
ⓓ. Pollen grain landing on the stigma
Correct Answer: Zygote formed after fertilisation
Explanation: Sporophyte is the diploid generation, and the first diploid cell of the new cycle is the zygote. After fertilisation, the zygote undergoes mitotic divisions to form the sporophyte body. In contrast, spores and gametophytes are haploid phases and cannot mark the start of the diploid generation. The zygote therefore represents the transition point from haploid to diploid in alternation of generations. Hence, the sporophyte begins with the zygote.
313. In the plant life cycle, meiosis typically occurs in the:
ⓐ. Gametophyte during gamete formation
ⓑ. Zygote during embryo development
ⓒ. Sporophyte during spore formation
ⓓ. Gamete just before fertilisation
Correct Answer: Sporophyte during spore formation
Explanation: Meiosis is the reduction division that converts diploid cells to haploid cells, restoring the haploid phase. In plants, this reduction step is usually associated with sporogenesis—formation of spores inside sporangia of the sporophyte. Gametes in plants are generally produced by mitosis in the haploid gametophyte, not by meiosis. This arrangement maintains alternation between haploid gametophyte and diploid sporophyte. Therefore, meiosis occurs in the sporophyte during spore formation.
314. Spores in plants are best described as:
ⓐ. Diploid cells that fuse to form a zygote
ⓑ. Haploid units formed by meiosis that develop into gametophytes
ⓒ. Diploid units formed by mitosis that develop into sporophytes
ⓓ. Haploid units formed by fertilisation that develop into seeds
Correct Answer: Haploid units formed by meiosis that develop into gametophytes
Explanation: Spores are produced from diploid sporophyte tissue through meiosis, so they are haploid. Their key role is to germinate and form the gametophyte generation, which will then produce gametes. Spores are not formed by fertilisation, and they are not gametes themselves. This spore-to-gametophyte transition is one half of alternation of generations. Hence, spores are haploid products of meiosis that develop into gametophytes.
315. The correct sequence of major events in alternation of generations is:
ⓐ. Gametophyte → meiosis → gametes → fertilisation → sporophyte
ⓑ. Sporophyte → fertilisation → spores → gametophyte → meiosis
ⓒ. Sporophyte → meiosis → spores → gametophyte → fertilisation → zygote → sporophyte
ⓓ. Gametophyte → fertilisation → spores → sporophyte → meiosis → gametes
Correct Answer: Sporophyte → meiosis → spores → gametophyte → fertilisation → zygote → sporophyte
Explanation: The diploid sporophyte produces haploid spores by meiosis, which then germinate to form the haploid gametophyte. The gametophyte produces gametes (by mitosis), and fertilisation restores diploidy by forming the zygote. The zygote develops by mitosis into the sporophyte, completing the cycle. This alternating haploid and diploid sequence is the core definition of alternation of generations. Therefore, the correct flow is sporophyte → meiosis → spores → gametophyte → fertilisation → zygote → sporophyte.
316. Which statement best distinguishes gametes from spores in plants?
ⓐ. Gametes are formed by meiosis; spores are formed by fertilisation
ⓑ. Gametes fuse to form a zygote; spores germinate to form a gametophyte
ⓒ. Gametes develop into sporophyte directly; spores develop into seeds directly
ⓓ. Gametes are always diploid; spores are always diploid
Correct Answer: Gametes fuse to form a zygote; spores germinate to form a gametophyte
Explanation: Gametes are sex cells whose defining role is fusion during fertilisation to produce a zygote. Spores are dispersal/propagule cells whose defining role is germination into a new haploid phase (gametophyte). In plants, spores are typically formed by meiosis in the sporophyte, while gametes are typically formed by mitosis in the gametophyte. Confusing these roles leads to common exam mistakes. Hence, gametes fuse to form a zygote, whereas spores germinate to form a gametophyte.
317. The chromosome number changes from diploid to haploid during:
ⓐ. Fertilisation
ⓑ. Mitosis in the gametophyte
ⓒ. Embryo development in the sporophyte
ⓓ. Meiosis in the sporophyte
Correct Answer: Meiosis in the sporophyte
Explanation: The diploid-to-haploid shift requires reduction of chromosome number, which happens only in meiosis. In plant life cycles, meiosis occurs in the sporophyte’s sporangia during spore formation, producing haploid spores. Fertilisation does the opposite (haploid to diploid) by fusion of gametes. Mitosis does not change chromosome number. Therefore, the diploid-to-haploid transition occurs during meiosis in the sporophyte.
318. If a plant has a dominant gametophyte and a dependent sporophyte, it best fits the life-cycle pattern typical of:
ⓐ. Many bryophytes
ⓑ. Most angiosperms
ⓒ. Most gymnosperms
ⓓ. Most pteridophytes
Correct Answer: Many bryophytes
Explanation: In bryophytes, the gametophyte is the main, free-living, photosynthetic plant body. The sporophyte develops from the zygote but remains attached to and nutritionally dependent on the gametophyte (often via the foot). This is a key conceptual contrast with vascular plants, where the sporophyte is dominant. The dominance relationship is a common classification question linked directly to alternation of generations. Hence, dominant gametophyte with dependent sporophyte is typical of many bryophytes.
319. In most vascular plants, the gametophyte is reduced mainly because:
ⓐ. It becomes diploid and replaces the sporophyte phase entirely
ⓑ. It is eliminated and spores directly form seeds without fertilisation
ⓒ. It becomes a cone-like structure that bears exposed ovules
ⓓ. It remains haploid but becomes small and protected within sporophytic tissues
Correct Answer: It remains haploid but becomes small and protected within sporophytic tissues
Explanation: As plants evolved, the sporophyte became the dominant, long-lived generation in vascular plants. The gametophyte did not disappear; it remained haploid but became reduced in size and often developed within or on the sporophyte, gaining protection from desiccation and environmental stress. In seed plants, this reduction is extreme, with gametophytes highly dependent on sporophytic structures. This trend improves reproductive efficiency on land. Therefore, the gametophyte remains haploid but becomes reduced and protected within sporophytic tissues.
320. Which pairing correctly matches generation and ploidy in alternation of generations?
ⓐ. Gametophyte—diploid; Sporophyte—haploid
ⓑ. Gametophyte—haploid; Sporophyte—diploid
ⓒ. Gametophyte—diploid; Sporophyte—diploid
ⓓ. Gametophyte—haploid; Sporophyte—haploid
Correct Answer: Gametophyte—haploid; Sporophyte—diploid
Explanation: Alternation of generations is defined by the regular alternation of a haploid gametophyte and a diploid sporophyte. The haploid gametophyte produces gametes, and fertilisation forms a diploid zygote that grows into the sporophyte. The diploid sporophyte produces haploid spores by meiosis, which regenerate the gametophyte. This consistent haploid–diploid alternation stabilizes chromosome number over generations. Hence, gametophyte is haploid and sporophyte is diploid.
321. A haplontic life cycle is correctly characterized by:
ⓐ. Dominant diploid phase with reduced haploid phase limited to gametes only
ⓑ. Dominant haploid phase, with the diploid phase restricted mainly to the zygote
ⓒ. Equal dominance of haploid and diploid phases as separate free-living plants
ⓓ. Complete absence of meiosis, so chromosome number never reduces
Correct Answer: Dominant haploid phase, with the diploid phase restricted mainly to the zygote
Explanation: In a haplontic life cycle, the main vegetative body is haploid, and the diploid stage is very short-lived, usually represented only by the zygote. Soon after formation, the zygote undergoes meiosis to restore the haploid condition, producing haploid cells/spores that grow into the haploid plant body. This pattern is common in many algae and is conceptually the opposite of diplontic cycles. Therefore, haplontic means dominant haploid phase with diploidy limited mainly to the zygote.
322. In a haplontic life cycle, meiosis occurs in the:
ⓐ. Zygote soon after fertilisation (zygotic meiosis)
ⓑ. Gametophyte during gamete formation
ⓒ. Sporophyte within sporangia of a large diploid plant body
ⓓ. Seed after dispersal during germination
Correct Answer: Zygote soon after fertilisation (zygotic meiosis)
Explanation: The hallmark of haplontic life cycle is that the diploid phase is reduced to the zygote. To return to the dominant haploid condition, the zygote undergoes meiosis soon after it forms. This is called zygotic meiosis and produces haploid cells that develop into the haploid plant body. In this life cycle, there is no multicellular diploid sporophyte stage. Hence, meiosis occurs in the zygote.
323. Which statement best explains why the sporophyte is absent as a multicellular stage in haplontic life cycles?
ⓐ. Because fertilisation does not occur, so zygote never forms
ⓑ. Because spores are formed by mitosis in a diploid sporophyte that remains hidden
ⓒ. Because gametes are diploid and directly form the haploid plant body after fusion
ⓓ. Because meiosis occurs immediately in the zygote, preventing diploid growth into a plant body
Correct Answer: Because meiosis occurs immediately in the zygote, preventing diploid growth into a plant body
Explanation: In a haplontic life cycle, the only diploid cell is the zygote. Since meiosis occurs in the zygote soon after fertilisation, the diploid condition is quickly reduced back to haploid. This immediate reduction means the zygote does not undergo extensive mitotic divisions to form a multicellular diploid sporophyte. As a result, the visible plant body remains haploid and the diploid generation is not expressed as a separate multicellular stage. Therefore, immediate zygotic meiosis prevents formation of a multicellular sporophyte.
324. A plant-like organism shows a long-lived haploid thallus and a brief diploid zygote that undergoes meiosis. This life cycle is:
ⓐ. Diplontic
ⓑ. Haplodiplontic
ⓒ. Haplontic
ⓓ. Sporophytic-dominant
Correct Answer: Haplontic
Explanation: A long-lived haploid thallus indicates that the haploid phase forms the main vegetative body. If the diploid phase is limited to the zygote and that zygote undergoes meiosis to generate haploid cells, the pattern matches a haplontic life cycle. This definition is standard in alternation-of-generations questions and is often tied to many algae. The key diagnostic is zygotic meiosis with no multicellular diploid generation. Hence, the life cycle is haplontic.
325. In haplontic organisms, the main vegetative body produces gametes by:
ⓐ. Meiosis, because it is diploid
ⓑ. Budding, because sexual reproduction is absent
ⓒ. Fusion of spores, because gametes do not exist
ⓓ. Mitosis, because it is haploid
Correct Answer: Mitosis, because it is haploid
Explanation: In a haplontic cycle, the dominant vegetative body is haploid. Haploid organisms cannot reduce chromosome number further by meiosis to produce gametes; instead, they form gametes by mitosis. These gametes fuse during fertilisation to form the diploid zygote. The zygote then undergoes meiosis to restore the haploid phase. Therefore, the main vegetative body produces gametes by mitosis.
326. Which of the following is the correct ploidy sequence in a haplontic life cycle?
ⓐ. 2n plant body → meiosis → n gametes → fertilisation → 2n embryo → 2n plant body
ⓑ. n plant body → mitosis → n gametes → fertilisation → 2n zygote → meiosis → n cells → n plant body
ⓒ. n plant body → meiosis → n spores → fertilisation → 2n zygote → 2n plant body
ⓓ. 2n plant body → mitosis → 2n gametes → fertilisation → 4n zygote → meiosis → 2n cells
Correct Answer: n plant body → mitosis → n gametes → fertilisation → 2n zygote → meiosis → n cells → n plant body
Explanation: The haplontic cycle is defined by a haploid vegetative body and a diploid phase restricted mainly to the zygote. The haploid plant body produces gametes by mitosis, and fertilisation forms the diploid zygote. To return to the dominant haploid phase, the zygote undergoes meiosis, producing haploid cells that develop into the haploid plant body. This sequence captures both the key events and ploidy transitions. Hence, the correct ploidy sequence is n body → n gametes → 2n zygote → meiosis → n body.
327. Which statement best contrasts haplontic and diplontic life cycles?
ⓐ. Haplontic has dominant haploid body; diplontic has dominant diploid body with haploid phase limited
ⓑ. Haplontic has dominant diploid body; diplontic has dominant haploid body with zygotic meiosis
ⓒ. Both have equal dominance of two independent multicellular phases
ⓓ. Both lack fertilisation and reproduce only by fragmentation
Correct Answer: Haplontic has dominant haploid body; diplontic has dominant diploid body with haploid phase limited
Explanation: In haplontic cycles, the visible plant body is haploid and diploidy is brief, usually confined to the zygote followed by meiosis. In diplontic cycles, the main organism is diploid and the haploid phase is reduced, often limited to gametes formed by meiosis. This contrast is essential for life-cycle classification and helps in identifying patterns across plant groups. It also highlights where meiosis is placed: zygotic in haplontic versus gametic in diplontic. Therefore, dominant haploid versus dominant diploid is the correct contrast.
328. Zygotic meiosis is most closely associated with which life cycle pattern?
ⓐ. Diplontic life cycle with gametic meiosis
ⓑ. Seed plant life cycle with ovary and fruit development
ⓒ. Haplodiplontic life cycle with two multicellular dominant phases
ⓓ. Haplontic life cycle with dominant haploid phase
Correct Answer: Haplontic life cycle with dominant haploid phase
Explanation: Zygotic meiosis refers to meiosis occurring in the zygote soon after fertilisation. This arrangement is a defining feature of the haplontic life cycle because it prevents development of a multicellular diploid sporophyte. Instead, haploid cells produced by zygotic meiosis grow into the dominant haploid plant body. The location of meiosis is therefore a strong indicator of the life-cycle type. Hence, zygotic meiosis is most closely associated with haplontic life cycles.
329. Which organismal group is most commonly associated with haplontic life cycles in standard plant classification discussions?
ⓐ. Many green algae with haploid thallus as the main body
ⓑ. Most ferns where sporophyte is large and vascular
ⓒ. Most seed plants where sporophyte dominates and gametophytes are reduced
ⓓ. Bryophytes where both generations are equally independent and long-lived
Correct Answer: Many green algae with haploid thallus as the main body
Explanation: Haplontic life cycles are commonly discussed in the context of many algae, especially those where the thallus is haploid and the diploid phase is limited to the zygote. This pattern fits the definition of dominant haploid body with zygotic meiosis. Ferns and seed plants show dominant sporophyte (diploid) generations, so they do not fit haplontic. Bryophytes have a dominant gametophyte but still possess a multicellular sporophyte, so they are not strictly haplontic. Therefore, many green algae are the most common association.
330. A student says “haplontic life cycle means the plant never becomes diploid.” The best correction is:
ⓐ. Correct, because fertilisation does not occur in haplontic cycles
ⓑ. Incorrect, because a diploid zygote forms but undergoes meiosis quickly to restore haploidy
ⓒ. Correct, because meiosis happens in the gametophyte producing diploid spores
ⓓ. Incorrect, because the dominant plant body is diploid and produces haploid gametes
Correct Answer: Incorrect, because a diploid zygote forms but undergoes meiosis quickly to restore haploidy
Explanation: Haplontic cycles do include a diploid phase, but it is extremely brief and usually represented only by the zygote formed after fertilisation. The key point is that meiosis occurs in the zygote soon after it forms, returning the life cycle to haploid cells that grow into the dominant haploid body. Therefore, diploidy is present but not expressed as a multicellular generation. This correction addresses the common misconception that “haplontic = no diploid stage.” Hence, haplontic includes a diploid zygote that quickly undergoes meiosis.
331. A diplontic life cycle is correctly characterized by:
ⓐ. Dominant diploid plant body, with haploid phase restricted mainly to gametes
ⓑ. Dominant haploid plant body, with diploid phase restricted to the zygote
ⓒ. Two free-living multicellular generations of equal importance
ⓓ. Only haploid spores form the main plant body in all conditions
Correct Answer: Dominant diploid plant body, with haploid phase restricted mainly to gametes
Explanation: In a diplontic life cycle, the main vegetative organism is diploid and persists as the dominant generation. The haploid phase is very brief and typically limited to gametes, which are produced by meiosis in the diploid organism. After fertilisation, the zygote grows by mitosis into the diploid body again, so there is no independent multicellular haploid gametophyte. This life cycle placement of meiosis and dominance pattern is the key diagnostic. Therefore, diplontic means diploid-dominant with haploidy mainly as gametes.
332. In a diplontic life cycle, meiosis occurs during:
ⓐ. Zygote development immediately after fertilisation
ⓑ. Spore formation in a multicellular haploid plant body
ⓒ. Gamete formation in the diploid organism (gametic meiosis)
ⓓ. Seed germination producing a haploid adult plant
Correct Answer: Gamete formation in the diploid organism (gametic meiosis)
Explanation: Diplontic cycles show a dominant diploid organism that produces haploid gametes by meiosis; this is called gametic meiosis. Since the haploid stage is restricted mainly to gametes, there is no separate haploid plant body producing gametes by mitosis. Fertilisation restores diploidy, and the zygote develops directly into the diploid organism by mitosis. Thus, the reduction in chromosome number occurs at gamete formation in the diploid phase. Hence, meiosis occurs as gametic meiosis in the diploid organism.
333. Which ploidy sequence best represents a diplontic life cycle?
ⓐ. n body → mitosis → n gametes → fertilisation → 2n zygote → meiosis → n body
ⓑ. 2n body → meiosis → n gametes → fertilisation → 2n zygote → mitosis → 2n body
ⓒ. 2n body → meiosis → n spores → mitosis → 2n body → fertilisation → n gametes
ⓓ. n body → meiosis → 2n spores → fertilisation → 4n zygote → mitosis → 2n body
Correct Answer: 2n body → meiosis → n gametes → fertilisation → 2n zygote → mitosis → 2n body
Explanation: In diplontic cycles, the organism is diploid (2n) and directly produces haploid gametes by meiosis. After fertilisation, the diploid zygote forms and grows by mitotic divisions into the diploid organism again. There is no multicellular haploid body; haploidy is limited to the gametes. This pattern precisely matches the sequence: 2n body → meiosis → n gametes → fertilisation → 2n zygote → mitosis → 2n body. Therefore, option B correctly represents diplontic life cycle ploidy changes.
334. The key reason a multicellular gametophyte is absent in diplontic life cycles is that:
ⓐ. Zygote undergoes immediate meiosis, preventing diploid growth
ⓑ. Gametes are diploid and do not require a haploid stage
ⓒ. Haploid phase is restricted to gametes, which fuse quickly and do not divide mitotically
ⓓ. Spores replace gametes, so fertilisation never occurs
Correct Answer: Haploid phase is restricted to gametes, which fuse quickly and do not divide mitotically
Explanation: In diplontic cycles, haploidy appears only as gametes produced by meiosis in the diploid organism. Since these gametes are specialized cells meant for fusion, they do not grow into a multicellular haploid body through mitosis. After fertilisation, the zygote is diploid and develops directly into the diploid organism, maintaining diploid dominance. This prevents formation of an independent gametophyte generation. Hence, the multicellular gametophyte is absent because haploidy is limited to gametes that do not undergo vegetative mitosis.
335. Diplontic life cycle is most closely associated with the term:
ⓐ. Zygotic meiosis
ⓑ. Gametic meiosis
ⓒ. Sporadic meiosis
ⓓ. Mitotic reduction
Correct Answer: Gametic meiosis
Explanation: The defining placement of meiosis in diplontic life cycles is during gamete formation by the diploid organism. This is called gametic meiosis and directly produces haploid gametes. Zygotic meiosis is associated with haplontic cycles, where the zygote undergoes meiosis soon after fertilisation. Therefore, identifying the type of meiosis is a powerful way to recognize the life-cycle pattern. Hence, diplontic life cycle is linked with gametic meiosis.
336. A life cycle showing a large diploid plant body, producing haploid gametes, and no free-living haploid generation is:
ⓐ. Haplontic
ⓑ. Haplodiplontic
ⓒ. Diplontic
ⓓ. Gametophytic-dominant
Correct Answer: Diplontic
Explanation: Diplontic cycles are characterized by a dominant diploid organism and a haploid stage restricted to gametes. The absence of a free-living multicellular haploid generation is central to the definition. The diploid body produces gametes by meiosis, gametes fuse, and the zygote develops by mitosis into the diploid body again. This makes diploidy the long-lived phase. Therefore, such a life cycle is diplontic.
337. Which statement best contrasts diplontic and haplontic life cycles?
ⓐ. Diplontic: meiosis in zygote; Haplontic: meiosis in diploid body during gamete formation
ⓑ. Diplontic: spores are dominant; Haplontic: seeds are dominant
ⓒ. Diplontic: two multicellular phases; Haplontic: no fertilisation at all
ⓓ. Diplontic: dominant diploid body; Haplontic: dominant haploid body with diploidy mainly as zygote
Correct Answer: Diplontic: dominant diploid body; Haplontic: dominant haploid body with diploidy mainly as zygote
Explanation: Diplontic cycles have a dominant diploid organism and haploidy largely limited to gametes produced by meiosis. Haplontic cycles have a dominant haploid organism and diploidy is mainly represented by a short-lived zygote that undergoes meiosis. This contrast is foundational for classifying life-cycle patterns and understanding where reduction division occurs. It also explains why gametophyte is absent in diplontic but present as the main body in haplontic. Hence, option B gives the correct contrast.
338. In a diplontic pattern, the zygote:
ⓐ. Undergoes meiosis immediately to form haploid spores
ⓑ. Is the only diploid stage and remains dormant permanently
ⓒ. Develops by mitosis into the diploid organism
ⓓ. Develops into a multicellular haploid thallus directly
Correct Answer: Develops by mitosis into the diploid organism
Explanation: In diplontic life cycles, the zygote is diploid and does not undergo immediate meiosis. Instead, it divides mitotically and grows into the diploid organism, maintaining the diploid-dominant condition. Chromosome reduction occurs later during gamete formation by meiosis in the diploid organism. This is why the diploid phase is continuous and long-lived. Therefore, the zygote develops by mitosis into the diploid organism.
339. If meiosis produces gametes directly, and there are no spores that grow into a haploid plant body, the life cycle fits:
ⓐ. Diplontic
ⓑ. Haplontic
ⓒ. Haplodiplontic
ⓓ. Sporophyte-dependent
Correct Answer: Diplontic
Explanation: Diplontic life cycles typically involve gametic meiosis, where meiosis directly produces haploid gametes. Since these gametes do not develop into a multicellular haploid body, there is no separate gametophyte generation. The zygote formed after fertilisation develops into the diploid organism again. This is distinct from haplodiplontic cycles where spores give rise to gametophytes, and from haplontic cycles where the haploid body is dominant. Hence, the described pattern fits diplontic.
340. A student says “diplontic means there is no haploid stage at all.” The best correction is:
ⓐ. Correct, because diploid organisms never form gametes
ⓑ. Incorrect, because the dominant body is haploid and diploid is only zygote
ⓒ. Correct, because meiosis is absent in diplontic life cycles
ⓓ. Incorrect, because haploid gametes are present, but there is no multicellular haploid generation
Correct Answer: Incorrect, because haploid gametes are present, but there is no multicellular haploid generation
Explanation: Diplontic life cycles do include a haploid stage, but it is brief and typically limited to gametes. These haploid gametes are produced by meiosis in the diploid organism and then fuse during fertilisation to restore diploidy. The key point is that haploid cells do not grow into a multicellular gametophyte generation in diplontic cycles. Therefore, it is incorrect to say there is no haploid stage at all; rather, there is no multicellular haploid generation. Hence, the correct correction is that haploid gametes exist but a haploid plant body does not.
341. A haplo-diplontic life cycle is best defined as:
ⓐ. Only haploid phase is multicellular, diploid phase is only the zygote
ⓑ. Only diploid phase is multicellular, haploid phase is only gametes
ⓒ. Both haploid gametophyte and diploid sporophyte are multicellular generations
ⓓ. Both haploid and diploid phases are single-celled and do not form plant bodies
Correct Answer: Both haploid gametophyte and diploid sporophyte are multicellular generations
Explanation: Haplo-diplontic life cycle means both phases of the life cycle are expressed as multicellular bodies—one haploid (gametophyte) and one diploid (sporophyte). The gametophyte produces gametes and fertilisation forms a diploid zygote. The zygote develops into a multicellular sporophyte, which produces haploid spores by meiosis. These spores grow into multicellular gametophytes again. This alternating pattern is a central feature in several plant groups and some algae.
342. In haplo-diplontic life cycles, meiosis is typically:
ⓐ. In the gametophyte to directly produce gametes
ⓑ. In the embryo to convert diploid tissues into haploid tissues
ⓒ. In the pollen grain before fertilisation to reduce chromosome number
ⓓ. In the sporophyte during spore formation inside sporangia
Correct Answer: In the sporophyte during spore formation inside sporangia
Explanation: In haplo-diplontic cycles, the diploid sporophyte produces haploid spores through meiosis, so chromosome number is reduced at sporogenesis. These spores germinate and form the haploid gametophyte, which then produces gametes by mitosis. Fertilisation restores diploidy by forming the zygote, which grows into the sporophyte by mitosis. This placement of meiosis is called sporic meiosis and is a hallmark of many land plants. Therefore, meiosis occurs in the sporophyte during spore formation.
343. The most appropriate description of the two generations in haplo-diplontic life cycles is:
ⓐ. Both gametophyte and sporophyte are present as multicellular phases, but dominance can differ among groups
ⓑ. Gametophyte is always absent, so only sporophyte is visible as a plant body
ⓒ. Sporophyte is always absent, so only gametophyte is visible as a plant body
ⓓ. Both generations exist only as microscopic single-celled stages without development
Correct Answer: Both gametophyte and sporophyte are present as multicellular phases, but dominance can differ among groups
Explanation: Haplo-diplontic cycles always include both multicellular gametophyte and multicellular sporophyte, but which one is dominant depends on the group. In bryophytes, the gametophyte is prominent and the sporophyte remains nutritionally dependent. In pteridophytes, the sporophyte is dominant and the gametophyte is relatively small and short-lived. Some algae may show roughly similar prominence of both phases. Hence, both phases are multicellular, but dominance varies.
344. Which set is most commonly treated as showing haplo-diplontic life cycle among land plants?
ⓐ. Many green algae like Chlamydomonas and Spirogyra
ⓑ. Bryophytes and pteridophytes
ⓒ. Gymnosperms and angiosperms
ⓓ. Many brown algae like Fucus along with seed plants
Correct Answer: Bryophytes and pteridophytes
Explanation: Bryophytes and pteridophytes show clear alternation between multicellular gametophyte and multicellular sporophyte generations, making them classic examples of haplo-diplontic life cycles in land plants. In bryophytes, the sporophyte remains attached to the gametophyte, while in pteridophytes the sporophyte becomes independent and dominant. This dual multicellular expression is the defining feature of haplo-diplontic pattern. By contrast, seed plants are mainly diplontic in the sense that gametophytes are extremely reduced and dependent. Therefore, bryophytes and pteridophytes fit best.
345. “Isomorphic alternation of generations” within a haplo-diplontic pattern means:
ⓐ. Gametophyte is large but sporophyte is single-celled
ⓑ. Sporophyte is large but gametophyte is only a gamete
ⓒ. Gametophyte and sporophyte are morphologically similar in appearance
ⓓ. Gametophyte and sporophyte are both absent as distinct stages
Correct Answer: Gametophyte and sporophyte are morphologically similar in appearance
Explanation: In isomorphic alternation, both multicellular generations exist and appear similar in external form, even though one is haploid and the other is diploid. This can make it difficult to distinguish the two phases by morphology alone without examining reproductive structures or chromosome number. The key concept is not dominance but similarity of body plan between generations. This is contrasted with heteromorphic alternation where the two generations look different. Hence, isomorphic alternation means the two generations are morphologically similar.
346. A classic example often used for isomorphic haplo-diplontic life cycle in algae is:
ⓐ. Fucus
ⓑ. Spirogyra
ⓒ. Ulva
ⓓ. Pinus
Correct Answer: Ulva
Explanation: Ulva is commonly cited as an alga where both gametophyte and sporophyte are multicellular and broadly similar in appearance, representing isomorphic alternation within a haplo-diplontic pattern. The sporophyte produces spores by meiosis, and spores develop into gametophytes which produce gametes. Fusion of gametes forms the zygote, which develops into the sporophyte. This example is frequently used to connect “haplo-diplontic” with “isomorphic” in conceptual MCQs. Therefore, Ulva is an appropriate example.
347. In haplo-diplontic life cycles, the gametophyte produces gametes by:
ⓐ. Mitosis, because the gametophyte is haploid and cannot reduce chromosome number further
ⓑ. Meiosis, because gametes must always be produced by reduction division
ⓒ. Mitosis, because the gametophyte is diploid and needs to maintain diploidy
ⓓ. Meiosis, because spores and gametes are formed in the same way
Correct Answer: Mitosis, because the gametophyte is haploid and cannot reduce chromosome number further
Explanation: The gametophyte is haploid, so meiosis is not the appropriate process for producing gametes; meiosis would require diploid cells. Instead, gametes are formed by mitosis in the gametophyte, maintaining haploidy in the gametes. Fertilisation then restores diploidy by forming the zygote, initiating the sporophyte generation. This division-of-labour between generations is central to alternation of generations. Therefore, gametes are produced by mitosis in the haploid gametophyte.
348. A key feature that makes haplo-diplontic life cycle different from diplontic life cycle is:
ⓐ. Meiosis occurs in the zygote in haplo-diplontic but in gametes in diplontic
ⓑ. Zygote is absent in haplo-diplontic but present in diplontic
ⓒ. Spores are absent in haplo-diplontic but present in diplontic
ⓓ. Haplo-diplontic has a multicellular gametophyte, while diplontic lacks a multicellular gametophyte
Correct Answer: Haplo-diplontic has a multicellular gametophyte, while diplontic lacks a multicellular gametophyte
Explanation: The defining contrast is the presence of an independent or distinct multicellular gametophyte generation in haplo-diplontic cycles. In diplontic cycles, the organism is predominantly diploid and the haploid phase is usually restricted to gametes, so a multicellular gametophyte does not occur. In haplo-diplontic cycles, spores form by meiosis and germinate into multicellular gametophytes. This creates a true alternation between two multicellular generations. Hence, multicellular gametophyte presence distinguishes haplo-diplontic from diplontic.
349. Which life-cycle statement is correct for pteridophytes within the haplo-diplontic pattern?
ⓐ. Gametophyte is always dominant and sporophyte remains permanently attached
ⓑ. Sporophyte is dominant and independent, while gametophyte is smaller but free-living
ⓒ. Sporophyte is absent and zygote undergoes immediate meiosis
ⓓ. Both generations are always identical and cannot be distinguished even by structures
Correct Answer: Sporophyte is dominant and independent, while gametophyte is smaller but free-living
Explanation: In pteridophytes, both generations are multicellular, but the sporophyte is the dominant, independent vascular plant body. The gametophyte is typically a small prothallus that can live independently but is short-lived compared to the sporophyte. Spores formed by meiosis develop into gametophytes, and fertilisation on the gametophyte produces the zygote that grows into the sporophyte. This fits the haplo-diplontic definition because both phases are multicellular. Therefore, dominant independent sporophyte with smaller free-living gametophyte is correct.
350. Which description best represents “haplo-diplontic” in one line for exam use?
ⓐ. Only zygote is diploid, rest of the life cycle is haploid
ⓑ. Only gametes are haploid, rest of the life cycle is diploid
ⓒ. Both haploid gametophyte and diploid sporophyte occur as multicellular phases with alternation
ⓓ. Only spores exist, and fertilisation is not part of the life cycle
Correct Answer: Both haploid gametophyte and diploid sporophyte occur as multicellular phases with alternation
Explanation: Haplo-diplontic means the life cycle alternates between a multicellular haploid gametophyte and a multicellular diploid sporophyte. The sporophyte produces haploid spores by meiosis, and spores grow into gametophytes. Gametophytes produce gametes, and fertilisation forms a diploid zygote that develops into the sporophyte. This captures the essential alternation and the presence of two multicellular generations. Therefore, the most accurate one-line exam definition is multicellular alternation of haploid and diploid phases.
351. In brown algae, the characteristic pigment that masks chlorophyll and gives the brown colour is:
ⓐ. Phycoerythrin along with phycocyanin in the phycobilisome complex
ⓑ. Chlorophyll b as the major accessory pigment in the light-harvesting system
ⓒ. Xanthophylls without any chlorophyll participation in photosynthesis
ⓓ. Fucoxanthin as a dominant accessory pigment along with chlorophyll a and c
Correct Answer: Fucoxanthin as a dominant accessory pigment along with chlorophyll a and c
Explanation: Brown algae show a typical pigment set where chlorophyll a is present for primary photosynthesis, while chlorophyll c and fucoxanthin act as important accessory pigments. Fucoxanthin absorbs light efficiently in blue-green wavelengths and visually dominates, giving the brownish appearance by masking green chlorophyll. This pigment pattern is a standard diagnostic feature used to separate brown algae from green and red algae in classification questions. Because pigments correlate with habitat and light conditions in water, this feature is repeatedly tested. Hence, fucoxanthin with chlorophyll a and c is the correct combination.
352. The reserve food material in many red algae is best identified as:
ⓐ. Floridean starch stored in the cytoplasm (not in chloroplast pyrenoids)
ⓑ. Starch stored in pyrenoids inside chloroplasts as in typical green algae
ⓒ. Laminarin stored in vacuoles along with mannitol as a sugar alcohol
ⓓ. Glycogen stored as the main carbohydrate reserve as in many fungi
Correct Answer: Floridean starch stored in the cytoplasm (not in chloroplast pyrenoids)
Explanation: Red algae characteristically store carbohydrates as floridean starch, which is deposited in the cytoplasm rather than within chloroplast pyrenoids. This point is used frequently to distinguish Rhodophyceae from Chlorophyceae, where starch is commonly associated with pyrenoids. The reserve food type, along with pigment phycoerythrin, forms a strong paired diagnostic for red algae. In exam questions, “floridean starch” is one of the most stable memory anchors for Rhodophyceae. Therefore, floridean starch in the cytoplasm is correct.
353. A plant group in which sporophyte is dominant, independent, and bears sporangia on sporophylls is best identified as:
ⓐ. Bryophytes, because the sporophyte is nutritionally dependent on the gametophyte
ⓑ. Thallophytes, because true sporophyte generation is absent as a distinct plant body
ⓒ. Fungi, because sporangia occur only on hyphae and not on sporophylls
ⓓ. Pteridophytes, because they are vascular and have a dominant sporophyte generation
Correct Answer: Pteridophytes, because they are vascular and have a dominant sporophyte generation
Explanation: Pteridophytes are the first vascular land plants in which the sporophyte becomes the dominant, well-differentiated and independent plant body. Sporangia are produced on specialized leaves called sporophylls, and in many ferns these are organized into sori. The gametophyte exists but is comparatively small and short-lived, often as a prothallus. This sporophyte dominance is a key evolutionary step and is frequently tested in life-cycle pattern MCQs. Hence, pteridophytes fit the described features.
354. “Seed habit” direction in heterosporous pteridophytes is best linked with:
ⓐ. Immediate formation of fruits around seeds due to ovary development after fertilisation
ⓑ. Increasing protection and reduction of female gametophyte associated with the megaspore
ⓒ. Complete elimination of fertilisation because spores convert directly into embryos
ⓓ. Replacement of spores with flowers, resulting in petals and nectar production
Correct Answer: Increasing protection and reduction of female gametophyte associated with the megaspore
Explanation: Heterospory produces microspores and megaspores, leading to male and female gametophytes that are often reduced and more protected than in homosporous forms. The megaspore is larger and supports development of the female gametophyte, and evolutionary trends favor retention and protection of this female side, improving embryo safety and nutrition. This resembles the logic of seed habit where the developing embryo is protected and provisioned. It does not mean true fruits or flowers, which are angiosperm features. Therefore, reduced and protected female gametophyte linked to megaspore is the correct idea.
355. The most accurate anatomical statement for typical gymnosperms regarding conduction is:
ⓐ. Xylem mainly has vessels and phloem has companion cells for rapid translocation
ⓑ. Xylem lacks tracheids and uses only parenchyma for water transport under pressure
ⓒ. Xylem uses sieve tube elements for water conduction and phloem uses vessels for sugars
ⓓ. Xylem mainly has tracheids and phloem commonly has sieve cells with albuminous cells
Correct Answer: Xylem mainly has tracheids and phloem commonly has sieve cells with albuminous cells
Explanation: In typical gymnosperms, water conduction is mainly through tracheids rather than vessel elements, which is a classic comparative point against angiosperms. Their phloem generally shows sieve cells (not well-developed sieve tube elements) and associated albuminous cells, reflecting a distinct conducting system. This anatomical package is repeatedly asked in “compare gymnosperms vs angiosperms” questions. It also connects to evolutionary trends in vascular tissue specialization. Hence, tracheids in xylem and sieve cells with albuminous cells in phloem is correct.
356. A moss sporophyte described as “foot–seta–capsule” indicates that:
ⓐ. The sporophyte is free-living and nutritionally independent like a fern plant body
ⓑ. The sporophyte is attached to the gametophyte and is structurally differentiated into these parts
ⓒ. The gametophyte is absent and the sporophyte arises directly from spores
ⓓ. The capsule is a fruit-like structure formed from an ovary wall after fertilisation
Correct Answer: The sporophyte is attached to the gametophyte and is structurally differentiated into these parts
Explanation: In mosses, the sporophyte develops from the zygote but remains attached to the gametophyte and depends on it for nourishment, especially through the foot. The seta acts as a stalk elevating the capsule, which is the spore-producing region. This “foot–seta–capsule” organization is a standard diagnostic description of moss sporophyte morphology. It also reinforces the concept that bryophytes have dominant gametophyte and dependent sporophyte. Therefore, the statement about attachment and differentiation is correct.
357. A life cycle in which both haploid and diploid phases are multicellular, but the two generations are morphologically distinct (one large, one small) is best termed:
ⓐ. Diplontic with gametic meiosis, because haploidy is restricted to gametes only
ⓑ. Haplontic with zygotic meiosis, because diploidy is restricted to zygote only
ⓒ. Haplo-diplontic with heteromorphic alternation of generations
ⓓ. Asexual cycle, because alternation of generations requires absence of fertilisation
Correct Answer: Haplo-diplontic with heteromorphic alternation of generations
Explanation: Haplo-diplontic indicates that both gametophyte (haploid) and sporophyte (diploid) exist as multicellular phases in the life cycle. If the two look different in form and size, it is heteromorphic alternation of generations. This is common across several plant groups where one generation becomes dominant and the other becomes reduced, yet both remain multicellular. The key is not equal appearance but the presence of two multicellular generations. Hence, haplo-diplontic heteromorphic alternation is the correct term.
358. In a diplontic life cycle, the haploid phase is mainly limited to:
ⓐ. A free-living multicellular gametophyte that dominates the vegetation
ⓑ. Gametes produced by meiosis in the diploid organism
ⓒ. Spores that germinate into a multicellular haploid thallus
ⓓ. The zygote, which undergoes meiosis immediately after formation
Correct Answer: Gametes produced by meiosis in the diploid organism
Explanation: Diplontic cycles have a dominant diploid organism, and chromosome reduction occurs during gamete formation by meiosis (gametic meiosis). Haploidy is therefore brief and usually restricted to gametes, which fuse quickly during fertilisation. The zygote remains diploid and develops by mitosis into the diploid organism, so there is no multicellular gametophyte stage. This definition is a frequent exam trap because students confuse it with haplontic cycles. Therefore, haploidy is mainly limited to gametes in diplontic life cycles.
359. The best reason angiosperms can form fruits whereas gymnosperms cannot is:
ⓐ. Angiosperms have spores but gymnosperms have only seeds, so fruit forms from spores
ⓑ. Gymnosperms have flowers but angiosperms lack flowers, so fruit forms only in gymnosperms
ⓒ. Fruits form from cone scales in angiosperms, while gymnosperms have ovaries that stay open
ⓓ. Angiosperms have an ovary that develops into a fruit; gymnosperms lack an ovary so seeds remain exposed
Correct Answer: Angiosperms have an ovary that develops into a fruit; gymnosperms lack an ovary so seeds remain exposed
Explanation: Fruit is fundamentally a post-fertilisation development of the ovary in angiosperms, enclosing the seeds formed from ovules. Gymnosperms do not possess a true ovary because ovules are borne exposed on sporophylls or cone scales, so there is no ovary wall to transform into a fruit wall. This directly explains “flowers + fruits” as a defining angiosperm character and “naked seeds” as a defining gymnosperm character. The concept is central to classification and frequently asked. Hence, ovary presence in angiosperms and absence in gymnosperms is the correct reason.
360. In Chlorophyceae, the reserve food and its typical association is best stated as:
ⓐ. Floridean starch stored in cytoplasm, typically linked with phycoerythrin dominance
ⓑ. Laminarin stored with mannitol, typically linked with fucoxanthin pigmentation
ⓒ. Starch stored in chloroplasts, often associated with pyrenoids
ⓓ. Glycogen stored in hyphae, typically linked with chitin in cell wall
Correct Answer: Starch stored in chloroplasts, often associated with pyrenoids
Explanation: Green algae (Chlorophyceae) characteristically store reserve food as starch, and a common exam detail is its association with pyrenoids within chloroplasts. This differentiates them from brown algae (laminarin/mannitol) and red algae (floridean starch in cytoplasm). The reserve food type is tightly linked with pigment and cell wall traits used in classification. Because these combinations are stable, they form a frequent “match the following” style pattern in exams. Therefore, starch stored in chloroplasts, often with pyrenoids, is correct.