In which kind of ovule, nucellar tissue intervenes between the micropyle and the embryo sac and must be penetrated by the pollen tube?

Consider the following statements and choose the correct answer:
1. In angiosperms the pollination consists of transference of the pollen grains from the anther to the stigma either by self-pollination or by cross-pollination
2. Pollen grain is shed from the pollen sac in the two-celled stage
3. The exine of each microspore grows out into a tube, called the pollen tube
4. The growth of pollen tube is stimulated by sugary substances secreted by the stigma

A

Only 1, 2 and 3 are true

B

Only 1, 3 and 4 are true

C

Only 1, 2 and 4 are true

D

1, 2, 3 and 4 are true

Consider the following statements regarding recurrent type apomixis and choose the correct answer:
1. There is meiosis during the formation of megaspore
2. The embryo sac is diploid in nature
3. The embryo sac never develops from a cell of the archesporium
4. The development of embryo from a cell of an embryo sac other than egg is known as apospory

A

Only 1, 2 and 3 are true

B

Only 1 and 4 are true

C

Only 2, 3 and 4 are true

D

Only 2 and 4 are true

Consider the following statements and choose the correct answer:
1. In Oenothera type of monosporic embryo sac, the embryo develops from the micropylar megaspore of the tetrad
2. Antipodal cells are altogether absent in Oenothera type
3. The genus Trapa forms an 8-nucleate embryo sac of the Polygonurn type
4. Oenothera type of embryo sac development has been found to be a characteristic feature of the entire family Onagraceae

A

Only 1, 2 and 3 are true

B

Only 2, 3 and 4 are true

C

Only 1, 2 and 4 are true

D

1, 2, 3 and 4 are true

Consider the following statements regarding the germination of pollen grain and choose the correct answer:
1. The content of the pollen is a true male gametophyte
2. The pollen tube comes out due to the protrusion of the exine through the germ pore
3. When the pollen grain has germinated, the pollen tube penetrates the stigma through the stigmatic papillae
4. Some stigmas have a continuous cuticle in which pollen tubes penetrate by enzyme action

A

Only 2, 3 and 4 are true

B

Only 1, 2 and 3 are true

C

Only 1, 3 and 4 are true

D

Only 1, 2 and 4 are true

In which of the following modes of entry, the pollen tube enters the ovule through the side of the integument nearest to the placenta, curves round the channel of the micropyle and reaches the embryo sac through the nucellus ?

A

Porogamy

B

Basigamy

C

Acrogamy

D

Mesogamy

Ovule is straight with funiculus, embryo sac, chalaza and micropyle lying on one straight line. It is

A

Orthotropous

B

Anatropous

C

Campylotropous

D

Amphitropous

Consider the following statements regarding Xenia and choose the correct answer:
1. If a white variety (yy) is pollinated with pollen from a yellow variety (YY), one of the male gametes (Y) will unite with the egg (y) to produce a hybrid embryo (Yy) which will act as a heterozygote for yellow endosperm in the next generation
2. The second male gamete (Y) will unite with the two polar nuclei (y, y) and produces the primary endosperm nucleus (Yyy) which is triploid
3. If a yellow endosperm variety (YY) is crossed with pollen from a white grained variety, the grains produced are white like the pollen parent

A

Only 1 and 2 are true

B

Only 2 and 3 are true

C

Only 1 and 3 are true

D

1, 2 and 3 are true

Determine the correctness or otherwise of the following Assertion (A) and the Reason (R).
Assertion: Somatic embryogenesis in plants is a twostep process comprising of embryo initiation followed by embryo production.
Reason: Embryo initiation is independent of the presence of 2, 4-dichlorophenoxyacetic acid, whereas embryo production requires a high concentration of 2, 4-dichlorophenoxyacetic acid.

A

Both (A) and (R) are true and (R) is the correct reason for (A)

B

Both (A) and (R) are true and (R) is not the correct reason for (A)

C

(A) is true but (R) is false

D

(A) is false but (R) is true

In which of the following genera the synergids of the embryo sac degenerate even before the entry of the pollen tube?

A

Mimusops

B

Taccawormia

C

Portulaca

D

Plumbagella

Pollen tube is attracted to the _____ end of the embryo sac.

A

micropylar

B

hilum

C

synergid

D

generative

In which kind of ovule, nucellar tissue intervenes between the micropyle and the embryo sac and must be penetrated by the pollen tube?

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