Answer:D
Explanation:
Both parent are Heterozygous for the sickle cell allele.
Both parent have sickle cell trait in which the both posses one abnormal allele of the hemoglobin beta gene (AS heterozygous genotype)
When two AS parents mate, probability of giving birth to a sickle cell anemia child is 1/4
AS + AS= AA, AS, AS, SS
First four are made of rock and rest are made of gases.
Atmospheres of all the planets are made of gases.
Answer:
A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow). This can occur only when the sun, Earth and moon are aligned (in "syzygy") exactly, or very closely so, with the Earth in the middle.
Explanation:
A. Extinction is a natural part of life on earth