Tag: sexual reproduction & its importance

Questions Related to sexual reproduction & its importance

Monocarpic plants are those which ________________.

biology reproduction in organisms sexual reproduction in organisms sexual reproduction & its importance modes of reproduction

  1. bear flowers with one ovary

  2. flower once and die

  3. bear only one flower

  4. all of the above.

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Correct Option: B
Explanation:

Monocarpic plants are those that flowers once during their Iife time, set seeds and then die, e.g.,bamboos.

Read the following statements about the reproductive cycles in mammals and select the correct ones.
(i) Oestrous cycle occurs in primate mammals.
(ii) In species with oestrous cycle, females are generally sexually active during oestrous phase.
(iii) Both the cycles show monthly recurrence.

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (ii) only

  4. (i), (ii) and (iii)

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Correct Option: C
Explanation:

Oestrous cycle occur in non-primates such as cows, dogs, etc. Menstrual cycle occurs in primates only. Menstrual cycle shows monthly recurrence but oestrous cycle does not.

So, the correct answer is '(ii) only

Oestrous cycle is reported in

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Cows and sheep

  2. Humans and monkeys

  3. Chimpanzees and gorillas

  4. None of these

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Correct Option: A
Explanation:
The females of placental mammals exhibit cyclical changes in the activities of ovaries and accessory ducts as well as hormone during the reproductive phase.
-In non-primate mammals like cows, sheep, deer, dog, tiger, etc., such cyclical changes during reproduction are called oestrus cycle whereas in primates ( monkey, apes and humans)  such cyclical changes are called Menstrual cycle.
So, the correct answer is 'Option A- Cows and sheep'.

The word estrus means

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Heat

  2. Blood

  3. Hormone

  4. None of the above

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Correct Option: A
Explanation:

The reproductive cycle of the non-primate females is called oestrous cycle. For example, in rats, horse etc. It can be divided into four phases proestrus, estrus, metestrus and diestrus. The word estrus means heat. It is a sign of sexual receptivity and fertility.

So, the correct option is A.

Monoestrous  and diestrous can be differentiated by

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Breeding cycle

  2. Reproductive cycle

  3. Ornithine cycle

  4. None of the above

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Correct Option: A
Explanation:

On the basis number of estrous cycle (breeding cycle), females of some species can be monoestrous and diestrous. Monoestrous animals are those in which only one estrous cycle can be seen in a year. For example, dogs, fox etc. Whereas, diestrous animals are those in which two estrous cycles are seen in a year. For example, horse, goats etc. So, the correct option is A.

Which of the following is known as "period of heat"?

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Metestrus

  2. Proestrus

  3. Estrus

  4. None of the above

Show answer
Correct Option: C
Explanation:

The reproductive cycle of the non primate females is called estrous cycle. For example, in rats, horse etc. It can be divided into four phases proestrus, estrus, metestrus and diestrus. Proestrus stage is the building up phase. The ovarian follicle becomes large and secretes estrogen which is necessary for the preparation of estrus and pregnancy. Estrus is the phase when ovulation takes place. It is also known as the period of heat and female is sexually receptive. Metestrus is the phase where corpus luteum forms under the influence of decreased estrogen and increased progesterone level. Diestrus is the phase where corpus luteum becomes functional and the progesterone level increases. So, the correct option is C.

The second half of the estrus cycle is controlled by

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Progesterone

  2. Estrogen

  3. Testosterone

  4. Both A and B

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Correct Option: A
Explanation:

The reproductive cycle of the non-primate females is called oestrous cycle. For example, in rats, horse etc. It can be divided into four phases proestrus, estrus, metestrus and diestrus. 

Proestrus stage is the building up phase. The ovarian follicle becomes large and secretes estrogen which is necessary for the preparation of estrus and pregnancy. 
Estrus is the phase when ovulation takes place. It is also known as the period of heat and female is sexually receptive ( can receive the male gamete). This phase is also regulated by the estrogen. 
Metestrus is the phase where corpus luteum forms under the influence of decreased estrogen and increased progesterone level. 
Diestrus is the phase where corpus luteum becomes functional and the progesterone level increases. So, the correct option is A.

Identify from the following group of animals which exhibit oestrus cycle

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Lion, deer, dog and cow

  2. Cow, monkey, elephant and ape

  3. Monkey, ape, man and elephant

  4. Lion, dog, monkey and ape

Show answer
Correct Option: A
Explanation:
Estrous cycle is a reproductive cycle of females of non-primate vertebrates. The gap between two estrus periods is known as estrous cycle. The females are highly receptive during estrus period. It is an indication of breeding period because one or more periods of estrus may occur during the breeding season of a species. Some animals like dogs are monoestrous as they have only one estrous phase in their breeding cycle. Males can recognize a female in heat by smell of pheromones. Lion, deer, dog and cow are non primates which exhibit estrus cycle.
So, the correct answer is option A.

A polyoestrus animal is

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Man

  2. Cat

  3. Rabbit

  4. Horse

Show answer
Correct Option: C
Explanation:

Estrous cycle is a reproductive cycle of females of non-primate vertebrates. The gap between two estrus periods is known as estrous cycle. The females are highly receptive during estrus period. It is an indication of breeding period because one or more periods of estrus may occur during the breeding season of a species. Polyoestrus are the animals which ovulates more than once in each breeding season. For example, rabbit. Cats are polyestrous but experience a seasonal anestrus in autumn and late winter. Horses are seasonal polyestrous. Humans have menstrual cycle they lack estrous cycle.

So, the correct answer is option C.

Nonprimate mammals have

botany modes of reproduction sexual reproduction in organisms sexual reproduction & its importance reproduction in organisms

  1. Menstrual cycle

  2. Oestrus cycle

  3. Breeding seasons

  4. Non breeding seasons

Show answer
Correct Option: B
Explanation:
A. The reproductive phase of primate animals is called Menstrual cycle. 
B. The reproductive phase of nonprimate animals is called Oestrus cycle. 
C. The seasons in which animals mate and produce offspring are called breeding seasons.
D. The seasons in which animals do not mate and produce offspring are called non-breeding seasons.
Hence, nonprimate mammals have oestrus cycle. So, the correct answer is 'Oestrus cycle'.