Development of gametophyte directly from the vegetative cells of the sporophyte without the formation of spores is known as:

Consider the following statements and choose the correct answer:
1. Spores of pine are borne in cones
2. In pine, the sporophyte is the smaller generation and after germination is dependent
3. In pine, there are two kinds of spores - microspores and megaspores
4. The male gametophyte of pine is a dependent structure and is reduced to six cells

A

Only 2 and 3 are true

B

Only 1, 2 and 4 are true

C

Only 1, 3 and 4 are true

D

Only 2 and 4 are true

The x-axis shows the temperature and the y-axis shows the killing time. This is with respect to spores in a suspension. Curve a = 100,000 spores/ml and b= 1,000 spores/ml. Above curve a is the region of spores killed and below the region b is the region of spores survived. Which of the following do we comprehend from the above?

A

Greater the spore concentration, more heat resistant the suspension

B

Spores of a given strain, all have the same heat resistance

C

Spores of the same strain have many spores of low heat resistance

D

Spores of the same strain have very few spores of high heat resistance

Which of the following statements is/are correct regarding vegetative propagation of plants? 1. Vegetative propagation produces a clonal population. 2. Vegetative propagation helps in eliminating the virus 3. Vegetative propagation can be practised most of the year. Select the correct answer using the code given below.

A

1 only

B

2 and 3 only

C

1 and 3 only

D

1, 2 and 3

In alternation of generation in plants, a sporophyte alternates with a gametophyte or vice- versa. Which of the following statements is INCORRECT for a sporophyte?

A

Sporophyte is dominant in Pinus.

B

Sporophyte is always diploid.

C

It is always independent and photosynthetic.

D

It produces spores.

Formation of gametophyte directly from sporophyte without meiosis is

A

Apospory

B

Apogamy

C

Parthenogenesis

D

Amphimixis

Which of the following statement(s) is/are CORRECT for antigen activated effector T cells?
P. CD4+ cells make contact with macrophages and stimulate their microbicidal activity.
Q. CD4+ cells make contact with B cells and stimulate them to differentiate into plasma cells.
R. CD8+ cells make contact with B cells and stimulate them to differentiate into plasma cells.
S. CD8+ cells make contact with virus infected cells and kill them.

A

Q only

B

Q and S only

C

P, Q and S only

D

P, Q, R and S

In the question two statements are given, followed by two conclusions, I and II. Read all the conclusions and then decide which of the given conclusions logically follow/s from the given statements. Statements: All white blood cells are red blood cells. Some blood cells are red blood cells. Conclusions: I. All blood cells are red blood cells, is a possibility. II. Some red blood cells are not blood cells.

A

Both conclusion I and conclusion II follow

B

Neither conclusion I nor conclusion II follow.

C

Only conclusion II follows.

D

Only conclusion I follows.

Ploidy level of Gametophyte and Sporophyte are . . . . . . . . and . . . . . . . . , rescpectively.

A

n, n

B

2n, n

C

2n, 3n

D

n, 2n

Vegetative cells are much more sensitive to heat than are spores.

A

True

B

False

Sporophyte bears spores in ___________

A

Capsule

B

Seta

C

Foot

D

Strond

Development of gametophyte directly from the vegetative cells of the sporophyte without the formation of spores is known as:

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