Answer:
Let the "barred" allele be caller B and the "non-white" allele b. Since chickens use chromosomes 
and 
to determine sex, hens would have chromosomes 
, and roosters would have chromosomes 
. A Z-linked gene is represented as a superscript on the chromosome, 
for the dominant allele and 
for the ressesive allele.
A barred hen would have a copy of B on its Z chromosome, a non-barred rooster would have both copies of b on both Z chromosomes. Using Punnet squares to represent the crosses we get the following cases:
That is a ratio of two barred heterozygote roosters to two non-barred hens. Crossing them we get:
That is a ratio of one barred heterozygote rooster to one barred hen to one non-barred rooster to one non barred hen.
Answer
A. centrioles
higher plant cells do not have centrioles in cell division.
The Sun shines because it is able to convert energy from gravity into light. ... This is what happens to the hydrogen gas in the core of the Sun. It gets squeeze together so tightly that four hydrogen nuclei combine to form one helium atom. This is called nuclear fusion.
Answer:
Atherosclerosis affects arteries, these blood vessels are elastic and flexible in order to allow good blood circulation
Explanation:
The blood vessels are classified into three types: arteries, veins, and capillaries. An artery is a muscular blood vessel that is able to carry blood away from the heart to different parts of the body. Healthy arteries need to be elastic and flexible in order to adjust their diameter and thus control blood flow by maintaining blood pressure. Arteriosclerosis is a chronic disease caused by the accumulation of fatty substances (especially cholesterol) in the artery walls, thereby difficulting blood circulation by thickening and hardening these walls.
Answer:
A. A scientific explanation for a set of observations that can be tested.
Explanation:
Theories can be proven or rejected, just like hypotheses.
Hope this helps!
