Double Fertilisation

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.

Three features which distinguish angiosperms are:

1. Naked seeds, flowers, double fertilization

2. Double fertilization, covered seeds, flowers

3. Dominant gametophyte, covered seeds, flowers

4. Dominant sporophytes, naked seeds, double fertilization

Q.

The contents of pollen tube are released into the

1. Cytoplasm of egg cel

2. Cytoplasm of synergid cell

3. Cytoplasm of central cell

4. Cytoplasm of antipodal cell

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. 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 egg cell with one male gamete and fusion of polar nuclei with one male gamete.
3. Fusion of the synergids with male gametes.
4. An event in which there is fusion of two diploid gametes.

Q. Which of the following shows triploid nature in flowering plants?

1. Megaspore
2. Microspore
3. Embryo
4. Endosperm

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

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

Q. What is the fate of the male gametes discharged in the synergid?

1. One fuses with the egg and other fuses with central cell nuclei
2. One fuses with the egg, other(s) degenerate in the synergid
3. All fuse with the egg
4. One fuses with the egg, other(s) fuse(s) with synergid nucleus

Q. A total of nuclei are involved in double fertilisation.

1. two
2. three
3. four
4. five

Q. The seeds of angiosperms contain reserve food material termed .

1. perisperm
2. endosperm
3. nucellus
4. pericarp

Q. The embryo sac in angiosperms is _________ celled and ________ nucleated structure.

1. seven and eight
2. eight and seven
3. four and five
4. two and three

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 angiosperms, each embryo-sac has a

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

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

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

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. Double fertilization is unique to

1. pteridophytes
2. bryophytes
3. gymnosperms
4. angiosperms

Q. Fertilisation leading to the formation of endosperm refers to

1. fusion of male gamete with diploid secondary nucleus
2. fusion of female gamete with diploid secondary nucleus
3. fusion of two diploid vegetative cells
4. fusion of two male gametes

Q. Which one of the following statements is wrong?

1. When pollen is shed at two-celled stage, double fertilization does not take place
2. Vegetative cell is larger than generative cell
3. Pollen grains in some plants remain viable for months
4. Intine is made up of cellulose and pectin

Q.

The diploid number of chromosomes in maize plant is 20.

1. True

2. False

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 egg cell with one male gamete and fusion of polar nuclei with one male gamete.
3. Fusion of the synergids with male gametes.
4. An event in which there is fusion of two diploid gametes.