In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
Answer:
The correct answer is option C.
Explanation:
As it is given that, a Mendelian cross is performed between two parents resulted by cross the parents. This suggests that the parents or P generation has zero recombination hence the genotype of Parents would be AA and aa in nature. Therefore, all the F1 generation offspring were Aa in nature. The selfing of the F1 offspring will be:
A a
A AA Aa
a Aa aa
Genotype: AA: Aa: aa :: 1:2:1
Phenotype: Dominant: recessive :: 3:1
Answer:
having crops that can grow at any temperature is the answer!
Answer:
Electrons Can Donate - 0
Electrons Can Receive- 2
Valence - 2
Explanation:
The electronic configuration of oxygen is 
. Thus in the p-orbital there is deficiency of two electrons. Hence, it can receive/share electron but it cannot donate electrons. This makes oxygen as a good electron acceptor. Since there is a deficiency of two electrons in the outermost shell of oxygen, the valence of oxygen in thus -2
