Tag: modes of reproduction

Conjugation is an exchange of genetic material i.e, mode of sexual reproduction in lower organisms.
Scalariform conjugation: It takes place during the night and between the recently divided cells of the conjugating participating filaments. Opposite cells of two filaments develope a conjugation tube by lying side by side and parallel to each other. The conjugation tube between two filament looks like a ladder, through which gamete from one gametangia passes through to fuse with the passive gamete of another filament.

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. Swelling in vulva and vagina can be noticed which indicates the preparation of sexual receptivity. The glands of uterus show hypertrophy due to the heat. 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 D.

• Hysterical pregnancy is the appearance of signs and symptoms associated with pregnancy when the person is not actually pregnant.
• It is also known as false pregnancy, phantom pregnancy, pseudopregnancy or pseudocyesis, 
• False pregnancy may sometimes be purely psychological.
• So, the correct option is 'All of the above'.

Estrous cycle comprises of the recurring physiologic changes that are induced by reproductive hormones in females of mammals. Monoestrous means having one estrous cycle per year. Diestrous means having two estrous cycles per year. Polyestrous means having many estrous cycles per year. A female dog is an example of diestrous. 

• Anestrus is a state or interval of sexual inactivity between periods of activity in periodically breeding mammals.
• The first phase (proestrus) of the estrous cycle is the building-up phase. During this phase the ovarian follicle (under the influence of FSH and LH) enlarges and begins to secrete estrogens.
• The end of sexual receptivity marks the beginning of metestrus, the post-ovulatory phase dominated by corpus luteum function. 
  
• So, the correct option is 'Anestrus'.

• The first phase (proestrus) of the estrous cycle is the building-up phase. During this phase the ovarian follicle (under the influence of FSH and LH) enlarges and begins to secrete estrogens.
  
• Estrus is the period of sexual receptivity. It is primarily initiated by the elevation in estrogens from mature follicles just prior to ovulation.
  
• The end of sexual receptivity marks the beginning of metestrus, the post-ovulatory phase dominated by corpus luteum function. 
  
• Anestrus is a state or interval of sexual inactivity between periods of activity in periodically breeding mammals.
  
• So, the correct option is 'Anestrus'.

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 ( can receive the male gamete). 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 B.

• The first phase (proestrus) of the estrous cycle is the building-up phase. During this phase the ovarian follicle (under the influence of FSH and LH) enlarges and begins to secrete estrogens.
• The end of sexual receptivity marks the beginning of metestrus, the post-ovulatory phase dominated by corpus luteum function. 
  
• Anestrus is a state or interval of sexual inactivity between periods of activity in periodically breeding mammals.
  
• So, the correct option is 'Anestrus'.

The reproductive cycle of the non primate females is called estrous cycle. The phase when the female is sexually receptive is called as estrus and the phase when the female is not sexually receptive is called as anestrus. When the pineal gland is exposed to light, there is release of the hormone melatonin. The hormone causes stimulation and repression of reproduction in different kind of breeders. This hormone regulated the activity and the release of GnRH (gonadotropin releasing hormone).

Estrous cycle is the reproductive cycle seen in non-primates female. It is the time from one heat period (estrous) to another heat period (estrous). This time period can vary from one species to another species. In goat the estrus frequency is of 21 days. So, the correct option is D.