Sweet potato is homologous to

Which of the following is a vestigial organ in humans?

Appearance of ancestral characters in the newborns,such as tail,monstral face,gill slits,multiple mammae,etc.,are known as:

$A$: Blood group analysis shows that human beings are more closely related to apes than to monkeys.
$R$: The blood groups $A$ and $B$ are found in apes but not in monkeys.

Which one of the following is not a vestigial organ in humans?

Reptilian character of $Archaeopteryx$ is . . . . . . .