Complete question:
A female is born with attached earlobes, which is a recessive phenotype. Which of the following statements about her parents must be true?
a. neither has the codominant allele.
b. Her father has an inactivated allele.
c. Both parents have the recessive allele.
d. Her mother carries the dominant allele.
Answer:
c. Both parents have the recessive allele.
Explanation:
A recessive trait is expressed in homozygous recessive genotypes only. If a female expresses the attached earlobe phenotype, she should be homozygous for the allele since the attached earlobe is a recessive trait. If allele "a" gives attached earlobe phenotype in homozygous genotype, the genotype of the female would be "aa". This means that the female has got one copy of the allele "a" from her either parents. Therefore, both her parents should have at least one copy of the recessive allele "a".
Answer:
A mutation
Explanation:
This is abnormal and can only be described as a mutation.
Answer: B. They allow for specific substance to travel throughout the cell.
Explanation: I know this because carrier proteins and channel proteins are some types of embedded proteins.
<span>Muscle cells are uniquely adapted to contractile function due to three main things. FIrst, they have a large capacity for storage of readily available glycogen to use for work. Second, they contain the actin and myosin cross-bridge cycling structure to perform a contraction of a muscle fiber. Finally, each fiber has central nervous innervation to control contraction and relaxation of the muscle fibers.</span>
