Sexual Reproduction in Flowering Plants — Page 9 | NEET Biology

Q81

Formation of gametophyte directly from sporophyte without meiosis is

A Apospory

B Apogamy

C Parthenogenesis

D Amphimixis

Correct Answer

Option A

Solution

(a) Apospory: gametophyte forms from sporophyte without meiosis.

Q82

Which is the most common type of embryo sac in angiosperms?

A Bisporic with two sequential mitotic divisions.

B Tetrasporic with one mitotic stage of divisions.

C Monosporic with three sequential mitotic divisions.

D Monosporic with two sequential mitotic divisions.

Correct Answer

Option C

Solution

(c) Monosporic Polygonum-type embryo sac is the most common, developing after one meiosis and three successive mitoses.

Q83

In oogamy, fertilization involves

A a small non-motile female gamete and a large motile male gamete

B a large non-motile female gamete and a small motile male gamete

C a large non-motile female gamete and a small non motile male gamete

D a large motile female gamete and a small nonmotile male gamete

Correct Answer

Option B

Solution

(b) Oogamy: large non-motile egg and small motile sperm.

Q84

An ovule which becomes curved so that nucellus and embryo sac lie at right angles to the funicle is

A Hemitropous

B Campylotropous

C Anatropous

D Orthotropous

Correct Answer

Option A

Solution

(a) Hemitropous: body of ovule at right angles to funicle; micropyle and chalaza in a horizontal plane.

Q85

Which one of the following represents an ovule where the embryo sac becomes horseshoe shaped?

A Amphitropous

B Circinotropous

C Atropous

D Antropous

Correct Answer

Option A

Solution

(a) Amphitropous: both ovule body and embryo sac are curved; embryo sac horseshoe-shaped.

Q86

Through which cell of the embryo sac does the pollen tube enter?

A Egg cell

B Persistent synergid

C Degenerate synergid

D Central cell

Correct Answer

Option C

Solution

(c) The pollen tube pierces and enters through the degenerate synergid.

Q87

The arrangement of the nuclei in a normal embryo sac in the dicot plants is

A 3+2+3

B 2+3+3

C 3+3+2

D 2+4+2

Correct Answer

Option A

Solution

(a) 3 (egg apparatus at micropylar end) + 2 (polar nuclei in centre) + 3 (antipodals at chalazal end).

Q88

Which one of the following pairs of plant structures has haploid number of chromosomes?

A Megaspore mother cell and antipodal cells

B Egg cell and antipodal cells

C Nucelus and antipodal cells

D Egg nucleus and secondary nucleus

Correct Answer

Option B

Solution

(b) Egg cell and antipodal cells are both haploid (products of meiosis).

Q89

Male gametes in angiosperms are formed by the division of

A generative cell

B vegetative cell

C microspore mother cell

D microspore.

Correct Answer

Option A

Solution

(a) Generative cell divides mitotically to produce two male gametes.

Q90

Which one of the following is surrounded by a callose wall?

A male gamete

B egg

C pollen grain

D microspore mother cell

Correct Answer

Option D

Solution

(d) The microspore mother cell (MMC) is surrounded by a callose wall.