Characteristics of Placental Mammals

 

1. i) In these mammals embryo completes its development inside the body of mother in uterus.

 

1. ii) After gestation period, young ones are born.

 

iii) Embryo remains in the uterus and gets its nourishment from mother through umbilical cord.

 

1. iv) Gestation period of these mammals is longer than the other mammals.

 

1. v) Gestation period is different in different animals. In mice it is 21 days, In rabbit it is 30-36 days, in cats and dogs it is 60 days, in cattle it is 250 days and in elephant it is 22 months.

 

1. vi) The condition of young ones of various mammals at birth is different.

 

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