Tag: life processes in living organisms- part 2

Questions Related to life processes in living organisms- part 2

Menstruation is triggered by an abrupt decline in the amount of

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Estrogen

  2. Progesterone

  3. Luteinizing hormone

  4. Follicle-stimulating hormone

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Correct Option: B
Explanation:

Progesterone belongs to a group of steroid hormones called progestogens. It is mainly secreted by the corpus luteum in the ovary during the second half of the menstrual cycle. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. Progesterone, a hormone secreted by the female reproductive system that functions mainly to regulate the condition of the inner lining (endometrium) of the uterus. When a woman has her menstrual period, her progesterone level is usually low during the first few days.

So the correct option is 'progesterone'.

The direct function of GnRH is to

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Stimulate production of estrogen and progesterone

  2. Initiate ovulation

  3. Inhibit secretion of pituitary hormones

  4. Stimulate secretion of LH and FSH

Show answer
Correct Option: D
Explanation:

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are called gonadotropins because stimulate the gonads - in males, the testes, and in females, the ovaries. They are not necessary for life but are essential for reproduction. These two hormones are secreted from cells in the anterior pituitary called gonadotrophs. Most gonadotrophs secrete only LH or FSH, but some appear to secrete both hormones.

So the correct option is 'stimulate secretion of LH and FSH'.

Peaks of LH and FSH production occur during

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Flow phase of the menstrual cycle

  2. Follicular phase of the ovarian cycle

  3. Period surrounding ovulation

  4. End of the luteal phase of the ovarian cycle

Show answer
Correct Option: C
Explanation:

Menstruation is the shedding of the lining of the uterus (endometrium) accompanied by bleeding. The menstrual cycle is regulated by hormones. Luteinizing hormone and follicle-stimulating hormone, which are produced by the pituitary gland, promote ovulation and stimulate the ovaries to produce estrogen and progesterone. The follicular phase ends when the level of luteinizing hormone increases dramatically (surges). The surge results in the release of the egg (ovulation) and marks the beginning of the next phase.

So the correct option is 'period surrounding ovulation'.

What is the source of increase in concentration of estrogen in the proliferative phase of menstrual cycle?

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Hypothalamus

  2. Anterior pituitary

  3. Ovary

  4. Corpus luteum

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Correct Option: D
Explanation:

  • The estrogen is secreted by the follicles and corpus luteum along with progesterone during the luteal phase of the menstrual cycle in. Its stimulation is done by the LH or luteinizing hormone which is secreted by the anterior pituitary.

So the correct option is 'Corpus luteum'

Development of an embryo directly from an egg cell without the participation of a male gamete is termed as 

botany life processes in living organisms- part 2 parthenocarpic fruits parthenogenesis the life cycle of plants

  1. Apospory

  2. Parthenogenesis

  3. Apogamy

  4. Both B and C

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Correct Option: D
Explanation:

Parthenogenesis is a form of asexual reproduction in which growth and development of embryos occur without fertilization. Parthenogenesis occurs naturally in many plants. The word parthenogenesis comes from the Greek; parthenos meaning virgin and genesis meaning birth.