Tag: human system

Questions Related to human system

How does the sperm break through the egg cell membrane? Choose the option you think is right.

biology human system reproductive systems different stages of growth reproductive system in humans

  1. Tears a hole in the membrane

  2. Dissolves the membrane with chemicals

  3. Bites through the membrane with teeth

  4. Squeezes through gaps in the membrane

Show answer
Correct Option: A

During the development of embryo which of the following occur first 

biology division for growth and reproduction reproductive systems different stages of growth reproductive system in humans human system

  1. Differentiation of tissue

  2. Differentiation of cells

  3. Differentiation of organs

  4. Differentiation of organ system

Show answer
Correct Option: B
Explanation:

Blastula differentiate into various regions and cells (blastomeres) of a particular region form a particular part of adult body, hence these areas are called presumptive areas and at this stage if cells of a particular area removed the adult lacks a particular part from its body.

Which distinguishes a morula from a blastula 

biology division for growth and reproduction reproductive systems different stages of growth reproductive system in humans human system

  1. Presence of more yolk

  2. Absence of yolk

  3. Presence of a cavity

  4. Absence of a cavity

Show answer
Correct Option: D
Explanation:

In microlecithal eggs or alecithal eggs, the cleavage results in the production of closely packed blastomeres. The stage in which solid mass of blastomeres appears is said to be morula, whereas blastula is hollow with a cavity known as blastocoel.

The events in sexual reproduction are
(i) pre-fertilisation
(ii) fertilisation
(iii) post-fertilisation
The sequential order of their occurence is

biology division for growth and reproduction reproductive systems different stages of growth reproductive system in humans human system

  1. (ii) - (i) - (i)

  2. (ii) - (ii) - (i)

  3. (i) - (ii) - (iii)

  4. (i) - (iii) - (iv)

Show answer
Correct Option: C
Explanation:

In spite of their morphological, anatomical and physiological differences, the fundamental events in sexual reproduction are the same. These events can be categorized as follows:

1. Pre-fertilization events: All the preparatory events which occur before the fusion of gametes are called pre-fertilization events. These include Gametogenesis and gamete transfer.
2. Fertilization: Fusion of two entire gametes ( one male and another female) to form a zygote.
3. Post-fertilization: All the events that occur during sexual reproduction after the fusion of gametes are called post-fertilization events.
So, the correct answer is '(i)-(ii)- (iii)'.

Match column I with column II and select the correct options from the codes given.

Column I Column II
A. Hypothalamus (i) Sperm lysins
B. Acrosome (ii) Estrogen
C. Graafian follicle (iii) Relaxin
D. Leydig's cells (iv) GnRH
E. Parturition (v) Testosterone
biology division for growth and reproduction reproductive systems different stages of growth reproductive system in humans human system

  1. A - (iv), B - (i), C - (ii), D - (iii), E - (v)

  2. A - (ii), B - (i), C - (iv), D - (iii), E - (v)

  3. A - (ii), B - (i), C - (v), D - (iv), E - (iii)

  4. A - (iv), B - (i), C - (ii), D - (v), E - (iii)

Show answer
Correct Option: D
Explanation:

The hypothalamus is a small region of the brain. It's located at the base of the brain, near the pituitary gland. It secretes hypothalamic hormone such as the GnRH or Gonadotropin stimulating hormone which further has effects on the pituitary gland. The acrosome is the anterior covering on the head of the sperm that consists of enzymes called lysins that can lyse the ovum membrane to penetrate and fertilize it. A Graafian follicle is a developed tertiary follicle and is responsible for the ovulation that occurs as a result of the surge in FSH and LH levels responsible for estrogen production. Leydig cells in the seminiferous tubules are responsible for the secretion of androgens such as testosterone. Parturition is the process of the delivery of the fetus and during this process, Relaxin is a hormone produced by the ovary and the placenta with important effects in the female reproductive system and during pregnancy. 

So, the correct option is 'A - (iv), B - (i), C - (ii), D - (v), E - (iii)'.

Match column I (terms) with column II (definitions) and select the correct options from the codes given.

Column I Column II
A. Parturition (i) Attachment of embryo to endometrium
B. Gestation (ii) Release of egg from Graafian follicle
C. Ovulation (iii) Delivery of baby from uterus
D. Implantation (iv) Duration between pregnancy and birth
E. Conception (v) Formation of zygote by fusion of the egg and sperm
(vi) Stoppage of ovulation and menstruation
biology division for growth and reproduction reproductive systems different stages of growth reproductive system in humans human system

  1. A - (ii), B - (iv), C - (i), D - (v), E - (vi)

  2. A - (iv), B - (iii), C - (i), D - (v), E - (ii)

  3. A - (v), B - (vi), C - (ii), D - (iii), E - (iv)

  4. A - (iii), B - (iv), C - (ii), D - (i), E - (v)

Show answer
Correct Option: D
Explanation:

Parturition is the delivery or childbirth of baby from the uterus. Gestation is the period of development during the carrying of an embryo or fetus inside viviparous animals and the duration between pregnancy and birth. Ovulation is the process of release of the ovum from the Graafian follicle as it ruptures. Implantation is the process of attachment of the zygote to the endometrial lining of the uterus. Conception refers to the post-fertilization fusion of the egg and sperm into the zygote.

So, the correct option is 'A - (iii), B - (iv), C - (ii), D - (i), E - (v)'.

Which of the following is related to the morphological changes during aging?

different stages of growth reproductive system in humans division for growth and reproduction human system biology

  1. The number of taste bud decreases.

  2. Decreased rate of cardiovascular functions.

  3. The reduction in the nephron.

  4. All of the above

Show answer
Correct Option: D
Explanation:
  • Ageing is a complex process that varies as to how it affects different people and even different organs. Most gerontologists (people who study aging) feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors.
  • Morphological changes during aging include the number of taste bud decreases, Decreased rate of cardiovascular functions and The reduction in the number of nephrons.
  • So, the correct answer is 'All the above'.

............... is the pigment which is mainly released due to degradation of phospholipids in the cell membrane and actively participates in the ageing.

different stages of growth reproductive system in humans division for growth and reproduction human system biology

  1. Lipofuchsin

  2. Free radical

  3. Cellular proteins

  4. None of the above

Show answer
Correct Option: A
Explanation:
  • Ageing is a complex process that varies as to how it affects different people and even different organs. Most gerontologists (people who study aging) feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors.
  • Lipofuscin (age pigment) is a brown-yellow, electron-dense, autofluorescent material that accumulates progressively over time in lysosomes of postmitotic cells, such as neurons and cardiac myocytes. It participates in the ageing phenomenon.
  • Hence Lipofuchsin is the pigment which is mainly released due to degradation of phospholipids in the cell membrane and actively participates in the ageing.
  • So, the correct answer is 'Lipofuchsin'.

Which of the following process can be related to ageing? 

different stages of growth reproductive system in humans division for growth and reproduction human system biology

  1. Mutation

  2. Chromosomal abbreviations

  3. Genetic recombinations

  4. Both A and B

Show answer
Correct Option: D

According to immunity theory, ageing is due to

different stages of growth reproductive system in humans division for growth and reproduction human system biology

  1. Accumulation of errors

  2. Reduced functioning of endocrine glands

  3. Degeneration of thymus

  4. Accumulation of waste products

Show answer
Correct Option: C
Explanation:

According to immunity theory, the immune system is programmed to decline its functions over time, and this fact is the main cause of aging. Thymic involution (shrinking of the thymus with age) is believed to be the main age-related change in the immune system, and this alteration begins after puberty.

So, the correct option is ‘Degeneration of thymus’.