There is no natural death in single-celled organisms like Amoeba and bacteria because:
1. They cannot reproduce sexually
2. They reproduce by binary fission
3. Parental body is distributed among the offspring
4. They are microscopic
The term ‘clone’ cannot be applied to offspring formed by sexual reproduction because:
1. | Offspring do not possess exact copies of parental DNA |
2. | DNA of only one parent is copied and passed on to the offspring |
3. | Offspring are formed at different times |
4. | DNA of the parent and offspring are completely different. |
Encystation during unfavorable conditions followed by multiple fission and sporulation when favorable conditions return is seen in:
1. | Sponges | 2. | Penicillium |
3. | Amoeba | 4. | Hydra |
Match the asexual reproductive structure in COLUMN I with organisms in COLUMN II and select the correct option from the codes given:
|
COLUMN I |
|
COLUMN II |
A. |
Zoospore |
a. |
Penicillium |
B. |
Conidia |
b. |
Chlamydomonas |
C. |
Buds |
c. |
Sponge |
D. |
Gemmule |
d. |
Hydra |
Options: | (A) | (B) | (C) | (D) |
1. | a | b | c | d |
2. | d | c | b | a |
3. | c | d | a | b |
4. | b | a | d | c |
Match vegetative propagules in COLUMN I with plants in COLUMN II and select the correct option from the codes given:
|
COLUMN I |
|
COLUMN II |
A. |
Rhizome |
a. |
Bryophyllum |
B. |
Bulbil |
b. |
Eichhornia |
C. |
Leaf buds |
c. |
Ginger |
D. |
Offset |
d. |
Agave |
Options: | (A) | (B) | (C) | (D) |
1. | a | b | c | d |
2. | d | c | b | a |
3. | c | d | a | b |
4. | b | a | d | c |
In the given diagrams each part A, B, C and D shows a reproductive structure in an organism marked as ‘X’. Select the option where all parts are correctly matched:
A. |
B. | ||
B. |
D. |
1. | A: Oogonium of Chara; B: Archegoniophore of Marchantia; C: Conidia of Penicillium; D: Offset of Eicchornia |
2. | A: Antheridium of Chara; B: Antheridiophore of Marchantia; C: Sporangiophores of Penicillium; D: Offset of Eicchornia |
3. | A: Oogonium of Chara; B: Antheridiophore of Marchantia; C: Conidia of Penicillium; D: Offset of Eicchornia |
4. | A: Antheridium of Chara; B: Archegoniophore of Marchantia; C: Conidia of Penicillium; D: Stolon of Eicchornia |
Consider the two statements:
I: | Eichhornia crassipes, the ‘terror of Bengal’ is an invasive weed. |
II: | It was introduced in India for its beautiful flower and shape of leaves. |
1. | Both I and II are correct and II explains I. |
2. | Both I and II are correct but II does not explain I. |
3. | I is correct but II is incorrect. |
4. | I is incorrect but II is correct. |
The ability to produce adventitious buds is exploited by gardeners for commercial propagation of:
1. | Bryophyllum | 2. | Agave |
3. | Water hyacinth | 4. | Ginger |
With the advent of adverse conditions, an organism capable of reproducing both asexually and sexually, will most likely:
1. | shift to asexual mode of reproduction |
2. | shift to sexual mode of reproduction |
3. | equally reproduce by both modes |
4. | die |
In several simple plants like algae, bryophytes, and pteridophytes, water is the medium through which gamete transfer takes place. To increase the chances of fertilization, such plants:
1. | Produce a large number of female gametes that are non-motile |
2. | Produce a large number of male gametes that is several thousand times the number of female gametes produced |
3. | Produce a large number of female gametes that is several thousand times the number of male gametes produced |
4. | Do not have the capability of reproducing asexually |