Answer:
this is not science questions it is of maths
This statement is true.
In the case of autosomal dominant disease, the person is either homozygous (which is very rare) or heterozygous. On the molecular level, either the mutation produced a new deleterious protein for the organism, or the mutation affected an existing protein in the physiological state and that a 50% activity is not enough to compensate for the needs. of the body.
In case of autosomal recessive disease, the sick person is always homozygous. If the two loci each have a different mutant allele, it is called a "composite heterozygote". People with autosomal recessive inheritance disorder have "mandatory heterozygote" parents.
The square denotes male. One parent is recessive, so X must have at least one recessive allele. B is the right answer.
Endosymbiosis is important because it is a theory that explains the origin of chloroplast and mitochondria. It is also a theory that explains how eukaryotic cells came to be.
I believe RNA
I hope this helps!
Have a great day!