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Medical
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Match the items given in Column I with those in Column II and select the correct option given below : 

  Column I   Column II
a. Proliferative Phase i. Breakdown of endometrial lining
b. Secretory Phase ii. Follicular Phase
c. Menstruation iii. Luteal Phase

 

  • Option 1)
    a b c
    ii iii i

     

  • Option 2)
    a b c
    i iii ii
  • Option 3)
    a b c
    iii ii i
  • Option 4)
    a b c
    iii i ii
 

Correct answer: Option 1  

Medical
513 Views   |  

The contraceptive 'SAHELI'

  • Option 1)

    is an IUD.

  • Option 2)

    increases the concentration of estrogen and prevents ovulation in females.

  • Option 3)

    blocks estrogen receptors in the uterus , preventing eggs from getting implanted.

  • Option 4)

    is a post - coital contraceptive.

 

Option 3 is aright answer

 

Medical
209 Views   |  

The difference between spermiogenesis and spermiation is

  • Option 1)

    In spermiogensis spermatozoa from sertoli cells are released into the cavity of seminiferous tubules , while in spermiation spermatozoa are formed .

  • Option 2)

    In spermiogenesis spermatozoa are formed , while in spermiation spermatids are formed .

  • Option 3)

    In spermiogensis spermatids are formed , while in spermiation spermatozoa are formed.

  • Option 4)

    In spermiogenesis spermatozoa are formed , while in spermiation spermatozoa are released from sertoli cells into the cavity of seminiferous tubules.

 

As we learnt in

Sperms -

The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis

-

Spermiation -

After spermiogenesis, sperm heads become embedded in the Sertoli cells, and are finally released from the seminiferous tubules by the process called spermiation

-

Spermiogenesis is transformation of spermatids into spermatozoa whereas spermiation is the release of the sperms from sertoli cells into the lumen of seminiferous tubule.

 


Option 1)

In spermiogensis spermatozoa from sertoli cells are released into the cavity of seminiferous tubules , while in spermiation spermatozoa are formed .

This is incorrect.

Option 2)

In spermiogenesis spermatozoa are formed , while in spermiation spermatids are formed .

This is incorrect.

Option 3)

In spermiogensis spermatids are formed , while in spermiation spermatozoa are formed.

This is incorrect.

Option 4)

In spermiogenesis spermatozoa are formed , while in spermiation spermatozoa are released from sertoli cells into the cavity of seminiferous tubules.

This is correct.

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Medical
122 Views   |  

Hormones secreted by the placenta to maintain pregnancy are

  • Option 1)

    hCG , hPL , progestogens , estrogens

  • Option 2)

    hCG , hPL , estrogens , relaxin , oxytocin

  • Option 3)

    hCG , hPL , progestogens , prolactin

  • Option 4)

    hCG , progestogens , estrogens , glucocorticoids

 
As we learnt in Foetal ejection reflex. - The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex. - wherein This triggers release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further secretion of...
Medical
348 Views   |  

Which of the following has proved helpful in preserving pollen as fossils ?

  • Option 1)

    Oil content

  • Option 2)

    Cellulosic intine

  • Option 3)

    Pollenkitt

  • Option 4)

    Sporopollenin

 

As we learnt in 

Structure of pollen grains -

The hard outer layer called the exine is made up of sporopollenin which is one of the most organic material known. It can withstand high temperatures and strong acids and alkali. No enzyme that degrades sporopollenin is so far known. Pollen grains exine has prominent apertures called germ pores where sporopollenin is absent.

- wherein

Pollen grains are well preserved as fossils because of the presence of sporopollenin.

 

 Sporopollenin cannot be degraded by enzyme; strong acids and alkali, therefore it is helpful in preserving pollen as fossil.

Pollenkitt – Help in insect pollination.

Cellulosic Intine – Inner sporoderm layer of pollen grain known as intine made up cellulose & pectin.

Oil content – No role is pollen preservation.

 


Option 1)

Oil content

This is incorrect.

Option 2)

Cellulosic intine

This is incorrect.

Option 3)

Pollenkitt

This is incorrect.

Option 4)

Sporopollenin

This is correct.

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Medical
371 Views   |  

Offsets are produced by

  • Option 1)

    Parthenocarpy

  • Option 2)

    Mitotic divisions

  • Option 3)

    Meiotic divisions

  • Option 4)

    Parthenogenesis

 

As we learnt in

Vegetative reproduction -

A form of asexual reproduction in plants.

- wherein

In plants, the units of vegetative propagation such as runner, rhizome, sucker, tuber, offset, bulb are all capable of giving rise to new offspring. These structures are called vegetative propagules

 

 

Offset is a vegetative part of a plant, formed by mitosis. Meiotic divisions do not occur in somatic cells. Parthenogenesis is the formation of embryo from ovum or egg without fertilisation. Parthenocarpy is the fruit formed without fertilisation, (generally seedless)


Option 1)

Parthenocarpy

This is incorrect.

Option 2)

Mitotic divisions

This is correct.

Option 3)

Meiotic divisions

This is incorrect.

Option 4)

Parthenogenesis

This is incorrect.

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Medical
71 Views   |  

Which of the following flowers only once in its life-time ?

  • Option 1)

    Mango

  • Option 2)

    Jackfruit

  • Option 3)

    Bamboo species

  • Option 4)

    Papaya

 
Medical
102 Views   |  

Pollen grains can be stored for several years in liquid nitrogen having a temperature of

  • Option 1)

    -196oC

  • Option 2)

    -80oC

  • Option 3)

    -120oC

  • Option 4)

    -160oC

 

3

Medical
100 Views   |  

Double fertilization is

  • Option 1)

    Fusion of two male gametes with one egg

  • Option 2)

    Fusion of one male gamete with two polar nuclei

  • Option 3)

    Fusion of two male gametes of a pollen tube with two different eggs

  • Option 4)

    Syngamy and triple fusion

 

As we learnt in

Primary Endosperm Cell (PEC) -

Since two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilisation, an event unique to flowering plants. The central cell after triple fusion becomes the primary endosperm cell (PEC) and develops into the endosperm while the zygote develops into an embryo.

-

 

 There are two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilization.

 


Option 1)

Fusion of two male gametes with one egg

This is incorrect.

Option 2)

Fusion of one male gamete with two polar nuclei

This is incorrect.

Option 3)

Fusion of two male gametes of a pollen tube with two different eggs

This is incorrect.

Option 4)

Syngamy and triple fusion

This is correct.

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