Non-disjunction involving the x-chromosome may occur during oogenesis and produce two kinds of eggs. if normal sperm fertilize these two types, which of the following pairs of genotypes are possible?

a. xx and xy
b. xxy and xo
c. xyy and xo
d. xyy and yo

The correct answer will be option-B

Explanation:

Non-disjunction is the process of the failure of the separation of the homologous chromosomes during cell division which could be observed during the meiosis I, meiosis II or mitosis.

If Non-disjunction takes place during the oogenesis then the resultant cells will be formed with XX and O gametes.

When a normal male sperm with XY fertilizes the cells then they will form four combinations:

1. XX  + X = XXX

2. XX + Y  = XXY

3. O + X = XO

4. O + Y = YO

Thus, in the given question option-B is the correct answer.

i think it's they require warm air

explanation:

tornados usually happen when it's raining right so when it's raining it cools down so if the temperature keeps changing then i think a tornado occurs sorry if it's wrong

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.