<span>The answer is
c. .mitochondrion</span>
Answer:
Explanation: The basic unit of a DNA is a Nucleotide. The nucleotide comprises of: the nitrogenous bases, a deoxyribose sugar and a phosphate group. The nitrogenous bases are the purines and pyrimidines . The include, Adenine, guanine, Thymine and cytosine
Genotype refers to the complete genetic make-up and can also be referred to as the alleles an organism carries on a particular gene.
John's genotype with unattached being dominant is Aa.
- Using A to represent the alleles
- Since his mother has attached earlobes, her condition can only be inherited in the recessive condition (aa).
- So for John to have an unattached earlobe, his father has to be either AA or Aa.
- Therefore John's genotype would be Aa
Learn more about genotype: brainly.com/question/22117
Answer:
D. If all of the offspring are short-tailed, the unknown individual is the homozygous dominant genotype.
Explanation:
The short tail phenotype is completely dominant over the long tail phenotype. When a short tailed salamander with unknown genotype is crossed with a homozygous recessive long tailed salamander, the cross is called testcross. Lets assume that the allele "S" gives "short tail" phenotype while the allele "s" gives "long tail" phenotype.
If the "short tailed salamander" with unknown genotype is homozygous dominant (SS), the process of the testcross will express only dominant trait (cross 1). On the other hand, if the "short tailed salamander" with unknown genotype is heterozygous dominant (Ss), segregation of alleles during gamete formation would form two types of gametes (cross 2). The 50% progeny would express the "long tail" phenotype while rest 50% will express the "short tail" phenotype.