A adaptation is a trait that helps an organism survive and reproduce.
Genetic drift happens by chance and can make an allele disappear completely from a gene pool, even if it was a desirable trait that should have been passed down to offspring. The random sampling style of genetic drift shrinks the gene pool and therefore alters the frequency the alleles are found in the population.
The ileum contains villi that project into the lumen and increase the amount of surface area.
Villi are small finger-like structures that project into the lumen of the small intestine. Villi increase the surface area of the intestinal walls for easy and quick absorption of digested food with the addition of digestive secretions. Villi vary in length from about 0.5 to 1 mm. They are usually found in large numbers at the beginning of the small intestine and they reduce toward the end of the tract.
The phenotype is - 75 % red and 25 %brown.
The genotype is hRhR - 25%
hBkhR - 50%
hBrhBk - 25%.
<h3><u>Explanation:</u></h3>
The cross given here is a simple dominant - recessive relationship between the three types of alleles of hair colour. The genes of this characteristics are present in autosomes, so will be segregated equally among all the sexes of the offsprings.
Now the genotype of auburn and red with black mother is given. So during gametogenesis, the gametes from the parents will be
Father - hBr and hR
Mother - hBk and hR
So, the probable combinations are hBrhBk, hBrhR and hBkhR.
The frequency of the combinations are 25%, 25% and 50% respectively.
The phenotypic ratio will be red : brown as 3:1.
Answer:
At the very bottom
Explanation:
When examining a cross section of rock layers, the oldest layer is on the bottom. This is because over time, newer rock layers continued to form on top of the oldest one.
