Tag: modes of reproduction

Questions Related to modes of reproduction

Monoestrus animals have

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

  1. One ovulation each month

  2. One egg

  3. One breeding season in a year

  4. One menses each month

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. 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.
So, the correct answer is option C.

Estrus cycle is indication of

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

  1. Breeding period

  2. Estrogen secretion

  3. Pregnancy

  4. Menopause

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Correct Option: A
Explanation:

Estrus cycle is the indication of the breeding period because it is a reproductive cycle of females of non-primate vertebrates and it is the period in which the female is highly receptive. 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 oestrous phase in their breeding cycle. Males can recognize a female in heat by the smell of pheromones.

So, the correct answer is option A.

What would be the number of chromosomes in the aleuronic cells of a plant with $42$ chromosomes in the root tip cells?

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

  1. $21$

  2. $42$

  3. $63$

  4. $84$

Show answer
Correct Option: A

Which of the following cannot be seen during estrus cycle?

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

  1. Estrogen produces strong sex surge

  2. Menstruation at the end of the estrous cycle

  3. Ovulation takes place during estrus phase

  4. None of the above

Show answer
Correct Option: B
Explanation:
  •  Animals that have estrus cycles resorb the endometrium if conception does not occur during that cycle. 
  • Animals that have menstrual cycles shed the endometrium through menstruation if conception does not take place.
  • So, the correct option is 'Menstruation at the end of the estrus cycle'.

Which of the following statement is true?
A) Sexual receptivity occurs all through the menstrual cycle.
B) Estrus prepares the female reproductive tract for copulation.
C) The hypertrophic lining is sloughed off as menstrual flow.

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

  1. Only A

  2. Both A and B

  3. Both A and C

  4. Both B and C

Show answer
Correct Option: D
Explanation:

Sexual receptivity is the stage when the female accepts the sperms for fertilization during the process of intercourse. The female becomes sexually receptive during the estrus phase of the menstrual cycle. 

There are two phases in the animals called as the estrus and the non-estrus phase in the reproductive cycle. The estrus is the receptive phase fro the females. This is the period when the female reproductive tract is ready for accepting the sperms for fertilization. 
The uterus is prepared for implantation by proliferation of the cells. This hypertrophic lining is removed and shed during the menstrual flow, if the egg does not gets fertilized. 
Thus, the correct answer is option D. 

Which of the following statement can be related to metestrus phase of an estrus cycle?

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

  1. The hypertrophy of glands of uterine mucosa

  2. Corpus luteum develops

  3. In absence of fertilisation the corpus luteum degenerates

  4. All of the above

Show answer
Correct Option: D
Explanation:
  • Metestrus phase is characterized by the activity of the corpus luteum, which produces progesterone. 
  • The uterine lining begins to appear and hypertrophy of glands is observed due to increased progesterone.
  • Just like menstrual cycle, absence of fertilisation leads to degeneration of corpus luteum in estrus cycle.
  • So, the correct option is 'All of the above'.

The estrus frequency of cow is

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

  1. 18 days

  2. 15 days

  3. 21 days

  4. !7 days

Show answer
Correct Option: C
Explanation:


  • Estrus cycle is the period of sexual activity in female mammals except for higher mammals, during which they are in heat i.e. ready to mate.
  • Cows can go into heat several times per year.
  • Estrus frequency of cow is 21 days i.e. it goes into heat with a duration of 21 days.
  • So, the correct option is '21 days'.

Proestrus bleeding in dogs is caused due to 

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

  1. Increase of the estradiol-17 hormone

  2. Inflammatory response of WBC

  3. Ovulation

  4. All of the above

Show answer
Correct Option: A
Explanation:

The reproductive cycle of the non primate females is called estrous cycle. It can be divided into four phases: proestrus, estrus, metestrus and diestrus. Proestrus stage is the building up phase. There is bleeding found in dogs during the proestrus phase. There is increase in the level of estradiol-17 hormone. This results in the movement or diapedesis of the red blood cells in the blood vessels which causes bleeding. 

Thus, the correct answer is option A. 

The female cat stays in heat for

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

  1. 18-21 days

  2. 16-21 days

  3. 14-21 days

  4. None of the above

Show answer
Correct Option: C
Explanation:
  • Estrus is the period in the sexual cycle of female mammals, except the higher primates, during which they are in heat—i.e., ready to accept a male and to mate.
  • The female cat stays in heat for 14-21 days i.e. it is ready to mate for this duration.
  • So, the correct option is '14-21 days'.

A difference between estrous and menstrual cycles is that

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

  1. Non-mammalian vertebrates have estrous cycles, whereas mammals have menstrual cycles

  2. The endometrial lining is shed in menstrual cycles but reabsorbed in estrous cycles

  3. Estrous cycles occur more frequently than menstrual cycles do

  4. Ovulation occurs before the endometrium thickens in estrous cycles

Show answer
Correct Option: B
Explanation:

Menstrual cycle occurs in primates (monkeys, apes and human beings). This cycle consists of the menstrual phase, the proliferative phase and the secretory phase and the broken endometrium is passed out during menstruation. The oestrous cycle occurs in non-primates such as cows, dogs, etc. It consists of a short period of estrus or heat followed by anoestrus or passive period. The broken endometrium is reabsorbed during the oestrous cycle.

So the correct option is 'the endometrial lining is shed in menstrual cycles but reabsorbed in the oestrous cycle'.