Answer:
C. On average, 25% of the children are affected by the autosomal recessive disease if both parents are carriers.
Explanation:
A recessive trait is always expressed in homozygous genotype only. To have progeny with recessive traits from two normal parents, both the parents should be heterozygous carriers. For example, two normal parents with genotype "Aa" have 25% of the chances to have a child with homozygous recessive genotype (Aa x Aa = 1/4 AA: 1/2 Aa: 1/4 aa).
An autosomal trait is equally expressed in both males and females. Inbreeding increases the homozygosity and thereby, increases the risk of expression of recessive traits which are otherwise masked in heterozygous genotype.
Answer is Middle Paleozoic era.
Paleozoic era was in 542 Ma - 245 Ma and it has 6 periods as Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian.
360-280 Ma - forming of vascular plants with woody tissues, seeds and veins.
430 - 410 Ma - forming of jawed fishes and first amphibians.
420 Ma - forming of scorpions
360 Ma - forming of crustaceans.
It’s the last one jeheuehekaiwjsdn
