Explanation:
The problem says that the hairless phenotype never breeds true. That means that it's not the result of a homozygous genotype (H₁H₁ or H₂H₂), so it is caused by the heterozygous genotype (H₁H₂).
The <u>expected </u>offspring from the cross between two Mexican hairless would be:
<h3>P
H₁H₂ x
H₁H₂</h3><h3>F1 1/4
H₁H₁, 2/4
H₁H₂ and 1/4
H₂H₂.</h3>
And the <u>expected</u> phenotypic ratio 3:1. However, the observed offspring shows a 2:1 ratio. What's happening?
If the observed phenotypic ratio in the offspring of a monohybrid cross (a single gene with two alleles) is 2:1, we can suspect that one of the genotypes is lethal in homozygosis and therefore does not appear in the progeny (the puppies are born dead).
If we proposed that the H₂ allele is lethal in homozygosis, then:
- The H₁H₁ genotype would cause normal puppies --> 1
- The H₁H₂ genotype would cause hairless puppies --> 2
- The H₂H₂ is lethal and causes the death of puppies --> 0
The phenotypic ratios change to 2:1, as observed in the experiment.
Answer:
C. Four Haploid Sperm Cells
Explanation:
Meiosis is a cell division measure that creates four haploid cells (gametes) from a solitary diploid germline cell. In males, meiosis is essential for spermatogenesis, the cycle to produce sperm. Sperm are the haploid cells that are produced in meiosis.
Meiosis is a profoundly moderated cell division measure in eukaryotes that produces 4 cells (gametes) from a solitary cell (mother). Nonetheless, Nondisjunction in the male of Drosophila causes much of the time sperm with an addition or loss of chromosomes.
Answer:
A scale and a tape measure.
Explanation:
Use the tape measure to get the volume and the scale to get the mass.
The neck is the Cervicis.
Hope this helps
