Double Fertilisation

Q. The total number of nuclei involved during double fertilisation are:

1. 2
2. 4
3. 5
4. 3

Q. What is the difference between parthenocarpy , apomixis and polyembryony ?

Q.

In the majority of angiosperms

1. there are numerous antipodal cells

2. egg has a filiform apparatus

3. a small central cell is present in that embryo sac

4. reduction division occurs in the megaspore mother cells

Q. Assertion: In angiosperms, each of the cells of an embryo-sac is haploid.
Reason: The embryo sac formation is preceded by meiosis.

1. Both A and R are correct and R is the correct explanation of A.
2. Both A and R are correct and R is not the correct explanation of A.
3. A is correct but R is incorrect.
4. Both A and R are incorrect

Q. To form four fully developed polygonum type of embryosacs in angiosperms, total number of meiosis and mitosis divisions generations required are respectively

1. 4, 12
2. 1, 3
3. 4, 4
4. 1, 12

Q. The egg apparatus inside the embryo sac in angiosperms is

1. two celled
2. three celled
3. seven celled
4. one celled

Q. During double fertilization, one male gamete fuses with egg and the other male gamete fuses with the ___________.

1. antipodals
2. secondary nucleus
3. synergids
4. PEN

Q. Which among the following is not a haploid structure in angiosperms?

1. Antipodals
2. Endosperm
3. Egg
4. Synergid

Q.

The embryo sac is also known as

1. Megasporangium

2. Megasporangium

3. Microsporangium

4. Megagametophyte

Q. Which of the following parts of the mature embryo sac start to degenerate after double fertilization?

I) Polar nuclei
II) Antipodal cells
III) Synergids
IV) Central cell

1. II, III, and IV
2. I, IV and II
3. I and III
4. II and III

Q. Embryo develops from the ___(a)_____at the ___(b)______ of the embryo sac.

1. (a) - zygote, (b) - chalazal end
2. (a) - PEN, (b) - micropylar end
3. (a) - zygote, (b) - micropylar end
4. (a) - PEN, (b) - chalazal end

Q. Which of the following statements describe double fertilisation in flowering plants?

1. An event in which two zygotes are formed in a single embryo sac.
2. Fusion of the synergids with male gametes.
3. An event in which there is fusion of two diploid gametes.
4. Fusion of the egg cell with one male gamete and fusion of polar nuclei with one male gamete.

Q. Label the following:

1. A - degenerating antipodal cells, B - zygote, C - PEC, D - PEN, E - degenerating synergids
2. A - degenerating synergids, B - endosperm, C - zygote, D - nucleus, E - degenerating antipodal cells
3. A - degenerating synergids, B - zygote, C - primary endosperm cell, D - primary endosperm nucleus, E - degenerating antipodal cells
4. A - degenerating antipodal cells, B - egg, C - central cell, D - polar nuclei, E - degenerating synergids

Q.

The ploidy of (i) male gamete, (ii) zygote, (iii) egg cell, (iv) polar nuclei and (v) PEN is

1. (i)- n, (ii)-2n, (iii)-n, (iv)-2n, (v)- 3n

2. (i)-n, (ii)-2n, (iii)-4n, (iv)-3n, (v)- 2n

3. (i)-2n, (ii)-n, (iii)-3n, (iv)-n , (v)- 2n

4. (i)-n, (ii)-2n, (iii)-3n, (iv)-n , (v)- n

Q. Double fertilization is fusion of

1. One male gamete with egg and other with secondary nucleus
2. Two eggs
3. Two eggs and polar nuclei with pollen nuclei
4. One male gamete with egg and other with synergid

Q. Assertion: Double fertilisation is unique to angiosperms.​
Reason: Triple fusion is the fusion of one of the sperm nuclei with the egg nucleus to form zygote.​

1. If assertion is true but reason is false​
2. If both assertion and reason are true but reason is not the correct explanation of assertion​
3. If both assertion and reason are false​
4. If both assertion and reason are true and reason is the correct explanation of assertion​

Q. In angiosperms, each embryo-sac has a

1. one-celled egg apparatus
2. three-celled egg apparatus
3. four-celled egg apparatus
4. two-celled egg apparatus

Q. In angiosperms, pollen tube liberate their male gametes into the

1. central cell
2. antipodal cell
3. egg cell
4. synergid

Q. Which of the following describes the function of the two male gametes and vegetative cell of the pollen grain?

1. One male gamete fuses with egg cell. The other male gamete and vegetative cell fuse with polar nuclei.
2. Both the male gametes fuse with the egg cell and vegetative cell forms the pollen tube.
3. One male gamete fuses with the egg cell, another male gamete fuses with polar nuclei and vegetative cell forms the pollen tube.
4. None of these.

Q. Post fertilisation, ________ develops into seed and ovary develops into ________.

1. ovules, seed coat
2. nucellus, fruit
3. integuments, fruit
4. ovule, fruit

Q. The phenomenon of double fertilization

1. involves the formation of an embryo only
2. involves the formation of an endosperm only
3. is a characteristic feature of gymnosperms
4. involves five nuclei

Q.

Explain why sexual reproduction in angiosperms is said to take place through double fertilisation and triple fusion. Also draw a labelled diagram of embryo sac to explain the phenomena.

Q. In a mature fertilised ovule of angiosperms, the haploid (n), diploid (2n) and triploid (3n) structures, respectively are the

1. egg, secondary nucleus and embryo
2. synergids, embryo and endosperm
3. antipodals, embryo and zygote
4. synergids, endosperm and antipodals

Q. Tegmen of the seed develops from

1. perisperm
2. funiculus
3. inner integument
4. outer integument

Q. Select the diploid structure present in the embryo sac

(a) Antipodal cells
(b) Definitive nucleus
(c) Zygote
(d) Synergid cells
(e) Egg cell

Q.

Embryo sac occurs in

1. Embryo

2. Axis part of embryo

3. Ovule

4. Endosperm

Q.

How is a zygote formed?

Q. The cell with filiform apparatus is present towards the __(a)____end of the embryo sac and it_____(b)__________after fertilisation.

1. a - chalazal, b - degenerates
2. a - micropylar, b - forms endosperm
3. a - micropylar, b - degenerates
4. a - chalazal, b - forms endosperm

Q. In Pteridophyta, reduction division occurs when :

1. Prothallus is formed
2. Spores are formed
3. Sex organs are formed
4. Gametes are formed

Q. Draw a neat labelled diagram of the different stages of an embryo sac. [3]