Class 12 Biology MCQs Chapter – 3
101. Phase of menstrual cycle that lasts for 7-8 days is :
( A ) Menstruation
( B ) Luteal phase
( C ) Ovulatory phase
( D ) Follicular phase
Answer-( D )
102. Which is not mesodermal in origin :
( A ) Nervous system
( B ) Circulatory system
( C ) Muscular system
( D ) Skeletal tissue
Answer-( A )
103. In uterus , endometrium increases in thickness in response to :
( A ) Oxytocin
( B ) Oestrogen
( C ) LH
( D ) Relaxin
Answer-( B )
104. Which is related to males ?
( A ) Oral pill
( B ) Tubectomy
( C ) Vasectomy
( D ) None of the above
Answer-( C )
105. Conversion of spermatid into a spermatozoon is called :
( A ) spermatogenesis
( B ) spermeiogenesis
( C ) spermatocytogenesis
( D ) gametogenesis
Answer-( B )
106. A primary spermatocyte is :
( A ) diploid
( B ) haploid
( C ) triploid
( D ) polyploid
Answer-( A )
107. Acrosome formation takes place from
( A ) centriole
( B ) golgibody
( C ) mitochondria
( D ) nucleus
Answer-( B )
108. Sperm tail shows the arrangement of microtubules which is :
( A ) 9 + 0
( B ) 9 + 2
( C ) 7 + 0
( D ) 7 + 2
Answer-( A )
109. One of the last event in the transformation of the spermatid into sperm is :
( A ) Acrosome formation
( B ) Microtubules formation
( C ) Tail formation
( D ) Elimination of cytoplasm
Answer-( D )
110. In a mammalian sperm , spirally arranged mitochondria ( Nebenkern ) around the axial filament are present in the region :
( A ) head
( B ) middle piece
( C ) end piece of tail
( D ) main piece of tail
Answer-( B )
111. How many secondary spermatocytes will be required to form 400 spermatozoa ?
( A ) 100
( B ) 200
( C ) 40
( D ) 400
Answer-( B )
112. Human eggs are almost free of yolk and are called :
( A ) microlecithal
( B ) alecithal
( C ) macrolecithal
( D ) mesolecithal
Answer-( B )
113. In telolecithal eggs , yolk is present :
( A ) on both sides
( B ) on one side
( C ) in centre
( D ) throughout the egg
Answer-( B )
114. Autogamy is favoured by :
( A ) homogamy
( B ) heterostyle
( C ) dichogamy
( D ) self sterility
Answer-( A )
