Free Biodiversity and Variety of Life MCQs with Answers
3,130 Biodiversity and Variety of Life MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Biological classification uses taxonomic ranks, binomial nomenclature and shared characteristics to organize life into kingdoms. The major groups include prokaryotes, protists, fungi, plants and animals, with comparisons based on cell type, cell wall, nutrition, body organization, reproduction and evolutionary relationships; prokaryotes lack a membrane-bound nucleus.
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- A. Mitotic division
- B. Formation of thick wall
- C. Differentiation
- D. Meiotic division
Explanation: In angiosperms, microsporogenesis i.e., formation of microspores (or pollen grains) occurs by the meiotic divisions of diploid microspore…
Correct answer: Meiotic division- A. Emergence of radicle
- B. Absorption of water for seed germination
- C. Initiation of pollen tube
- D. Release of male gametes
Explanation: In a pollen grain, exine is thin or absent at certain places. These areas may have thickened intine or deposition of callose.
Correct answer: Release of male gametes- A. Bees
- B. Butterflies
- C. Birds
- D. Wind
Explanation: Anemophily is an abiotic means of pollination by wind and, being nondirectional, a wasteful process as the pollen would reach the stigma…
Correct answer: Bees- A. Citrus
- B. Gossypium
- C. Triticum
- D. Brassica
Explanation: In nucellar polyembryony, some of the nucellar cells surrounding the embryo sac start dividing.
Correct answer: Citrus- A. Legumes
- B. Lilies
- C. Grasses
- D. Orchids
Explanation: Wind pollination is common in grasses because they typically have small, inconspicuous flowers that lack showy petals and nectar to…
Correct answer: Grasses- A. Embryo sac
- B. Ovule
- C. Endosperm
- D. Pollen sac
Explanation: In angiosperms, the functional megaspore develops into the embryo sac, which is a structure within the ovule that contains the female…
Correct answer: Embryo sac- A. It brings about the opening of the pollen tube
- B. It guides the pollen tube from a synergid to the egg
- C. It helps in the entry of the pollen tube into a synergid
- D. It prevents the entry of more than one pollen tube into the embryo sac
Explanation: Within the embryo sac three cells are grouped together at the micropylar end and constitute the egg apparatus.
Correct answer: It helps in the entry of the pollen tube into a synergid- A. Egg cell
- B. Persistent synergid
- C. Degenerated synergids
- D. Central cell
Explanation: The pollen tube enters into the embryo sac at the micropylar end. This entry may be between egg and one synergid or between wall of embryo…
Correct answer: Persistent synergid- A. Central cell
- B. Antipodal cells
- C. Egg cell
- D. Synergids
Explanation: On reaching of pollen tube inside the embryo sac, the 2 male gametes are discharged through a subterminal pore in pollen tube.
Correct answer: Synergids1990. In grasses, what happens in the microspore mother cell for the formation of mature pollen grains?
- A. One meiotic and two mitotic divisions
- B. One meiotic and one mitotic division
- C. One meiotic division
- D. One mitotic division
Explanation: Grass is a monocot plant. Primary sporogenous cell gives rise to microspore mother cells or pollen mother cells.
Correct answer: One meiotic and one mitotic division- A. Only monosporic
- B. Only bisporic
- C. Only tetrasporic
- D. Any of these
Explanation: On the basis of number of megaspore nuclei taking part in development of female gametophyte or embryo sac, there are 3 types of embryo…
Correct answer: Only monosporic- A. Two polar nuclei and one male gamete
- B. One polar nucleus and one male gamete
- C. Ovum and male gamete
- D. Two polar nuclei and two male gametes
Explanation: Double fertilization is the simultaneous occurrence of syngamy and triple fusion.
Correct answer: Two polar nuclei and one male gamete- A. Two cotyledons
- B. Many cotyledons
- C. No cotyledon
- D. One cotyledon
Explanation: Sunflower (Helianthus) belongs to Family Asteraceae of dicotyledons. A dicot embryo has an embryonal axis and 2 cotyledons attached to it…
Correct answer: Two cotyledons- A. Cotyledons
- B. Endocarp
- C. Endosperm
- D. Integuments
Explanation: Double fertilization is the simultaneous occurrence of syngamy and triple fusion.
Correct answer: Endosperm- A. 16
- B. 12
- C. 8
- D. 4
Explanation: Pollen grains or microspores are formed inside anther, which is the fertile portion of stamen or microsporophyll.
Correct answer: 16- A. 75
- B. 100
- C. 25
- D. 50
Explanation: Pollen grains or microspores are formed inside anther, which is the fertile portion of stamen or microsporophyll.
Correct answer: 25- A. Tomato
- B. Potato
- C. Citrus
- D. Turmeric
Explanation: Presence of more than one embryo inside the seed is called polyembryony. It is more common in gymnosperms than angiosperms.
Correct answer: Citrus- A. Angiosperms
- B. Anatropous
- C. Gymnosperms
- D. Bryophytes
Explanation: Double fertilisation is the characteristic feature of angiosperms. This phenomenon first observed by Nawaschin, 1898 in Lilium and…
Correct answer: Angiosperms- A. Cells of apical meristem
- B. Cells of lateral meristem
- C. Microspores and anther wall
- D. Microsporocytes
Explanation: Meiosis is best observed in dividing microsporocytes. Microsporocytes or microspore mother cells after meiosis give rise to microspore.
Correct answer: Microsporocytes- A. Two eggs
- B. Two eggs and polar nuclei with pollen nuclei
- C. One male gamete with egg and other with synergid
- D. One male gamete with egg and other with secondary nucleus
Explanation: Double fertilization is the simultaneous occurrence of syngamy and triple fusion.
Correct answer: One male gamete with egg and other with secondary nucleus