Class 12 Biology Sexual Reproduction in Flowering Plants: NCERT Solutions for Question 4
With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
An ovule is a female megasporangium where the formation of megaspores takes place.
The various parts of an ovule are –
(1) Funiculus – It is a stalk-like structure which represents the point of attachment of the ovule to the placenta of the ovary.
(2) Hilum – It is the point where the body of the ovule is attached to the funiculus.
(3) Integuments –They are the outer layers surrounding the ovule that provide protection to the developing embryo.
(4) Micropyle – It is a narrow pore formed by the projection of integuments. It marks the point where the pollen tube enters the ovule at the time of fertilization.
(5) Nucellus – It is a mass of the parenchymatous tissue surrounded by the integuments from the outside. The nucellus provides nutrition to the developing embryo. The embryo sac is located inside the nucellus.
(6) Chalazal – It is the based swollen part of the nucellus from where the integuments originate.
More Questions From Class 12 Biology - Chapter Sexual Reproduction in Flowering Plants
- Q:- With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
- Q:- What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
- Q:- What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.
- Q:- Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.
- Q:- What is apomixis and what is its importance?
- Q:- Differentiate between:
(a) Hypocotyl and epicotyl
(b) Coleoptile and coleorrhiza
(c) Integument and testa
(d) Perisperm and pericarp - Q:- Why is apple called a false fruit? Which part(s) of the flower forms the fruit?
- Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:- Explain the role of tapetum in the formation pollen-grain wall.
- Q:- Arrange the following terms in the correct developmental sequence:
Popular Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- What do you think is the significance of reproductive health in a society?
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Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine. - Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
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10 Comment(s) on this Question
Give full answer with diagram
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Long type answer lag raha hai
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