Ur answer is number 2 i'm almost sure of i
In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
The difference is really simple, it's basically whether it's an plant or animal
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
Answer:
A meter is a metric unit of length used worldwide by scientists to measure lengths and distances between objects.