Botany MCQs on “Plant Kingdom – Gymnosperms-2”.
1. Which of the following is incorrect about reproduction in Gymnosperms?
a) Microsporangium contain microsporocytes that undergo meiosis to form microspores
b) Microspores further undergo reduction division to form microgametophyte
c) Microgametophyte is also called as Pollen grain
d) Wind, water and insects act as dispersal agents for pollination
Answer: b
Clarification: Microsporangia contain microsporocytes that undergo meiosis to form microspores. Microspores further undergo reduction division to form microgametophyte. Microgametophyte is also called as Pollen grain. Wind, water and insects act as dispersal agents for pollination.
2. Which among the following are incorrect about Gymnosperms?
a) In Ginkgo, female cones are absent
b) Gymnosperms may be either dioecious or monoecious
c) The embryo that grows after fertilization is exoscopic in nature
d) Companion cells in phloem are absent
Answer: c
Clarification: Female cones are absent in Ginkgo, Cycads and Taxus. Gymnosperms may be either dioecious or monoecious i.e. they may be either homosporous or heterosporous. The embryo that grows after fertilization is endoscopic in nature. Vessels in xylem and companion cells in phloem are absent in Gymnosperms.
3. Which among the following are incorrect about Gymnosperms?
a) On reaching female gametophyte, the pollen grains produce a tube like structure that carries sperms to the egg
b) Fertilization in Gymnosperms can also be described as siphonogamic
c) Ovules in Gymnosperms are unprotected unlike that of angiosperms
d) Every megaspore that is produced after meiosis undergoes mitosis to form a female gametophyte
Answer: d
Clarification: On reaching female gametophyte, the pollen grains produce a tube like structure that carries sperms to the egg. Fertilization in Gymnosperms can also be described as siphonogamic. Ovules in Gymnosperms are unprotected unlike that of angiosperms. Among the four megaspores that are formed after meiosis only one megaspore is functional and the rest becomes defunct.
4. Gymnosperms and Angiosperms are together called as __________
a) Spermatophyta
b) Sporophyta
c) Dermitophyta
d) Embryophyta
Answer: a
Clarification: Gymnosperms (Gymno = Naked, spermae = seeds) and Angiosperms (Angio = Covered, spermae = seeds) are together called as Spermatophyta (Spermae = seeds, phyta = plants).
5. The megasporangium tissue acts as nutritive element for the embryo.
a) True
b) False
Answer: a
Clarification: After fertilization, the zygote develops into an embryo and the megasporangium tissue provides nutrition for the development of the embryo. Apart from providing nutrition to the embryo, megasporangium tissue plays a vital role in the development of the female gametophyte.
6. Which among the following is incorrect?
a) The reduced male gametophyte is termed as pollen grains
b) Pollen grains may be monosaccate, disaccate, trisaccate or non-saccate
c) Megasporangium tissue is soft and non-woody
d) After mitosis, a megaspore forms female gametophyte with two or three archegonia that undergoes fertilization
Answer: c
Clarification: The reduced male gametophyte is termed as pollen grains. Pollen grains may be monosaccate, disaccate, trisaccate or non-saccate. Megasporangium tissue is hardy and woody in nature. After mitosis, a megaspore forms female gametophyte with two or three archegonia that undergoes fertilization.
7. A fertilized embryo takes several years to form seeds in the case of Gymnosperms.
a) True
b) False
Answer: b
Clarification: A fertilized embryo takes several years to mature and form seeds in the case of Gymnosperms. Polyembryogeny is very common in case of Gymnosperms.
8. The covering outside an ovule in Gymnosperms is called as __________
a) Integument
b) Air sac
c) Embryo sac
d) Carpel
Answer: a
Clarification: The covering outside an ovule in Gymnosperms is called integument. It has a tiny hole at one end that allows germination of pollen grains that are carried to female gametophyte through air and water.
9. Pollen grains are covered with __________
a) Integument
b) Air sac
c) Embryo sac
d) Carpel
Answer: b
Clarification: Pollen grains are dispersed to different parts of the world through air, water and insects. They are equipped with wings (some don’t have wings) and are covered with an air sac.
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