The answer is "D"
The body's first line of defense is also known as Innate immunity and incudes mucous membranes. Both the intact skin and mucous membranes of the body offer a high degree of protection against pathogens.
A good example is the mucous membrane of the respiratory tract. It is lined up with cilia and covered with mucus. The coordinated beating of the cilia drives the mucus up to the nose and mouth where the trapped bacteria can be expelled.
(Lymph nodes and white blood cells belong to the second line of defense, not the first)
Independent Variable: Scenarios (such as different times of the day or places) used to check if a person will become depressed or not.
Dependent Variable: Number of people diagnosed with depression.
Constant: Amount of people who do not understand depression.
Control: How your setting can impact mood and performance.
Answer:
F1 Females - all wild type
F1 Males - all wild type
F2 Females - - all wild type
F2 Males - 1/2 wild type, 1/2 vermilion
Explanation:
The wild-type allele (Xᵛ⁺) is dominant over vermilion (Xᵛ), which is a sex-linked trait.
Female flies have two X chromosomes, male flies have one X and one Y chromosome.
A homozygous wild-type female fly (Xᵛ⁺Xᵛ⁺) is mated with a vermilion male fly (XᵛY).
The female parent can only produce Xᵛ⁺ gametes.
The male parent can produce either Xᵛ or Y gametes.
When gametes from both parents fuse, the F1 offspring will have the genotypes Xᵛ⁺Xᵛ (females with wild type eyes) and Xᵛ⁺Y (males with wild type eyes).
The F1 females can produce Xᵛ⁺ and Xᵛ gametes. The F1 males can produce Xᵛ⁺ and Y gametes.
When the F1 individuals interbreed, the gametes combine to give rise to the F2 offspring. The possible combination of gametes that will give the different genotypes and phenotypes in the F2 are:
- Xᵛ⁺Xᵛ⁺ females with wild type eyes
- Xᵛ⁺ Y males with wild type eyes
- Xᵛ Xᵛ⁺ females with wild type eyes
- Xᵛ Y males with vermilion eyes
The function of the limb is to help them get around and move. They might be similar in the way they’re structured? I don’t have a picture so I can’t tell. And you can assume that at one point these four animals all shared a common ancestor. Hope I helped!
