Menstrual cycles occur in:
1. all animal females
2. all female mammals
3. female monkeys, apes, and humans
4. only in human females
Identify the incorrectly matched pair:
|
Organism |
Chromosome number in a meiocyte |
1. |
Ophioglossum |
630 |
2. |
Housefly |
12 |
3. |
Maize |
20 |
4. |
Butterfly |
380 |
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 |
A reproductive strategy that involves the development of a female (rarely a male) gamete (sex cell) without fertilization is called:
1. | Parthenogenesis | 2. | Parthenocarpy |
3. | Panmixis | 4. | Amphimixis |
Consider the two statements:
I: | Organisms exhibiting external fertilisation show great synchrony between the sexes. |
II: | Such organisms release a large number of gametes into the surrounding medium (water). |
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. | Both I and II are incorrect. |
A major disadvantage of external fertilization is:
1. | Lack of variation in the progeny |
2. | The number of progeny produced can only be one or few |
3. | The offspring are extremely vulnerable to predators threatening their survival up to adulthood |
4. | The progeny have a very short life span and a low reproductive potential |
When compared to external fertilization, in cases where internal fertilization takes place in sexually reproducing organisms:
1. | The progeny are afforded better protection |
2. | The number of male gametes are highly reduced while the number of female gametes is increased |
3. | Male gamete is non-motile and the female gamete has to reach it |
4. | In seed plants the non-motile male gametes are carried to the female gamete by pollen tubes |
I. | Only I and II are correct |
II. | Only III and IV are correct |
III. | Only I and IV are correct |
IV. | Only II and III are correct |
What would be correct for haploid cells in the body of a higher animal like humans?
1. | They are a typical example of human cells. |
2. | They are caused by allelic variation. |
3. | They are gametes, which allow sexual reproduction. |
4. | They contain 46 chromosomes. |
Birds in captivity (as in poultry farms) :
1. | lay eggs seasonally |
2. | can be made to lay eggs throughout the year |
3. | exhibit estrous cycles |
4. | exhibit menstrual cycles |
Identify the correct statements:
I. | Clear-cut vegetative, juvenile, and senescent phases are seen only in perennial plants. |
II. | Neelakurinji flowers once in 12 years. |
III. | Bamboo flowers only once in their lifetime. |
1. | Only III |
2. | Only II and III |
3. | Only I and II |
4. | I, II, and III |