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:
Watson and Crick discovered that DNA has a double helix shape, consisting of two polynucleotide chains held together by bonds between complementary bases. DNA replication is semi-conservative: half of the parent DNA molecule is conserved in each of the two daughter DNA molecules.
Explanation:
I looked it up lol
Sickle cell disease has a benefit in malaria infection because it makes the parasites easier to eliminate. This makes a person with sickle cell disease is more likely to survive the malaria infection, which found many in Africa.
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Sickle cell disease has a few drawbacks because it makes the red blood cells less durable, which lead to the destruction of more red blood cells. In normal condition(where malaria doesn't exist like in America), this gene will make the organism less likely to survive than those who don't have the gene.</span>
