Which one of the following statements is false in respect of viability of mammalian sperm ?

  • Sperm is viable for only up to 24 hours

  • Survival of sperm depends on the pH of the medium and is more active in alkaline medium

  • Viability of sperm is determined by its motility

  • Viability of sperm is determined by its motility


A.

Sperm is viable for only up to 24 hours

Sperms are viable for 24 h to 48 h , whereas the human ovum is viable only for 24 h.

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Which one of the following events in not associated with ovulation in human female?

  • Decrease in oestradiol

  • Full development of Graafian follicle

  • Release of secondary oocyte

  • Release of secondary oocyte


A.

Decrease in oestradiol

Oestradiol levels fall after ovulation and before mensuration while, its level peak prior to ovulation. Oestradiol are not associated with ovulation. Decrease in oestradiol level result in the cessation of menstruation. 

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Which one of the following is wrong about Chara?

  • upper oogonium and lower round antheridium

  • Globule and nucule present on the same plant

  • Upper antheridium and lower oogonium

  • Upper antheridium and lower oogonium


C.

Upper antheridium and lower oogonium

Both antheridium and oogonium are the males and the female reproductive structure respectively. They have sterile jackets on their surface. In almost all algae of class - Chlorophyceae, the structure like globule ( male sex organ) present lower side, while the nucule (female sex organ) present upper side of sterile vegetative (leaf-like) structure. 

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Cycas and Adiantum resemble each other in having 

  • seeds

  • motile sperms

  • cambium

  • cambium


B.

motile sperms

Multiciliated motile sperms are found in both Cycas (gymnosperm) and Adiantum or walking fern (pteridophyte). Seeds and cambium are present in Cycas (quite common in gymnosperm) but absent in pteridophytes. Vessels are absent in both.

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Which of the following layers in an antral follicle is acellular?

  • Granulosa

  • Theca interna

  • Stroma

  • Stroma


D.

Stroma

Follicles that form an antrum during maturation are called antral follicle or Graafian follicle.
During the development of the follicle, a glycoprotein polymer capsule called the zona pellucida which is acellular, forms around the oocyte, separating it from the surrounding granulosa cells. 
This layer remains with the oocyte after ovulation and contains enzymes that catalyse with sperm to allow penetration. 

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