Human ancestors who left cave paintings were
Neanderthal man
Cro- magnon man
Java ape man
Peking man
A man of blood group- A marries a woman of blood group- AB, which type of progeny would indicate that man is heterozygous?
O
B
A
AB
Balbiani rings are the structural features of
allosomes
polytene chromosomes
autosomes
lampbrush chromosomes
How many sperm cells are present in an average (3 mL) ejaculation?
200 million
300 million
400 million
500 million
The permanent decrease in population number occurs due to
migration
natality
emigration
mortality
Which of the following is not a vestigial structure in Homo sapiens ?
Third molar
Epiglottis
Plica semilunaris
Pyrimidalis muscle
The extra structure that provides nutrition to the embryo is
umbilicus
amnion
chorian
placenta
D.
placenta
Placenta is a connection between foetus and mother formed from fusion of allantois, chorian and uterine endometrium.
Functions:
(a) Provides nourishment
(b) Helps in respiration
(c) Helps in excretion
Amnion and chorian are foetal membranes. Amnion helps in protection and chorian helps in nourishment.