Answer:
1/2
Explanation:
Let's assume that the allele "p" is responsible for PKU in the homozygous state. According to the given information, both the parents are unaffected by the disorder but have an affected child. This means that both the parents carry at least one copy of the recessive allele responsible for the disease. Therefore, the genotype of each of the parents is Pp. A cross between Pp and Pp would produce progeny in following ratio=
Pp x Pp = 1/4 PP: 1/2/ Pp: 1/4 pp
Therefore, the probability that their next child will carry just one recessive allele is 1/2.
2. This statement rephrases the principle of uniformitarianism. The correct option among all the options that are given in the question is the third option or the penultimate option.
3. A worm would would stand a poor chance of being fossilized because worms have no hard parts. The correct option among all the options that are given in the question is the third option.
A bone is tissue. It forms a part of the skeletal system which is made up bones, joints, ligaments and cartilage.
Cells work together in groups known as tissues. A tissue is defined as a group of similar cells working together to carry out a certain task. Examples are skin, bone, blood.
Tissues in turn are grouped together to form organs. An organ is defined as a group of tissues that work together to carry out a certain task . Examples are heart, lungs, liver.
Is part of the eath's layers and outer core of the earth