Tag: the life cycle of animals

Questions Related to the life cycle of animals

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

Animals having both the sexes in one body are called __________.

  1. Nematods

  2. Hermaphrodite

  3. Parasite

  4. Pseudocoelomate

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Certain animals like earthworm have both the sexes i.e., male and female reproductive system in one body itself. Such organisms are called as hermaphrodite. They tend to reproduce sexual by copulating.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

HeLa cells used in cell biology are 

  1. Cancerous cells grown in cancer research laboratory

  2. Cervical cancer cell derivatives

  3. Both (A) and (B)

  4. None of the above

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

HeLa cells, are cancerous cells  belonging to a cultured strain isolated from a patient suffering from cervical cancer. The designation HeLa is derived from the name of the patient, Henrietta Lacks. This cell line has been extensively used in cell biology research like cancers, effect of various carcinogens and xenobiotics on human cells etc. 

So.option C is correct.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

Which of the following cells are present in mammalian testes and help to nourish sperms 

  1. Leydig cells

  2. Oxyntic cells

  3. Interstitial cells

  4. Sertoli cells

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sertoli cells are non-gametic cells in the seminiferous tubules which provide nourishment for developing sperms.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

Assertion : There is generally monospermy in most of animals.

Reason : Vitelline membrane of ovum checks polyspermy.

  1. Both Assertion and Reason are true and Reason is a correct explanation of Assertion

  2. Both Assertion and Reason are true but Reason is not a correct explanation of Assertion

  3. Assertion is true but Reason is false

  4. Both Assertion and Reason are false

  5. Assertion is false but reason is true.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Entrance of a single sperm into an oocytes called monospermy generally monospermy is found in most of the animals. Cortical granules are extruded in the perivitelline space by exocytosis and some of these are attached along the inner surface of vitelline membrane which now thickens and becomes impervious to any other sperm entry. It is now called fertilization membrane. It prevents the polyspermy.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

In most of the mammals the testes are situated outside the abdominal cavity because 

  1. Sperms produced in scrotal sac are more in number

  2. Sperms produced in abdominal cavity are provided with less motility

  3. Sperms produced in scrotal sac require lesser temperature for their best fertilization capacity

  4. Sperms produced in scrotal sac are bigger

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Testes in mammals are present out side the abdominal cavity because maturation of sperm needs low temperature. The temperature of scrotum is below (2 to 4$^{o}C$) than abdominal cavity.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

Assertion : In morula stage, cells divide without increase in size.

Reason : Zona pellucida remain undivided till cleavage is complete.

  1. Both Assertion and Reason are true and Reason is a correct explanation of Assertion

  2. Both Assertion and Reason are true but Reason is not a correct explanation of Assertion

  3. Assertion is true but Reason is false

  4. Both Assertion and Reason are false

  5. Assertion is false but reason is true.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Zygote divide vertically to form two blastomeres. This is followed by a vertical division and a horizontal division. Now, several divisions occur forming equal sized blastomeres called morula. There is no increase in size of cells. Zona pellucida is a transparent non cellular layer surrounding egg cell. It remains undivided till the cleavage is complete.

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

In crocodiles male sex is predominant at

  1. Low temperature

  2. Intermediate temperature

  3. High temperature

  4. Ratio is genetically determined.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In crocodilians, sex determination is temperature-dependent. Males are typically produced at higher temperatures, while females are produced at lower temperatures.