During sexual reproduction, each parent contributes A
a double helix of chromosomes.

B
one strand of chromosomes, or half of the new organism's DNA.

C
a dominant gene and a recessive gene.

D
multiple mutated cells.

Explanation:

Sexual reproduction involves gametes. These are sex cells (sperm for males and eggs/ovum for females).

These sex cells are formed during meiosis. During this process, two rounds of cellular division occur, so there are four resulting haploid cells. Haploid means they contain half of the genetic information.

These cells are haploid because during fertilization, a sperm and egg fuse to form a zygote. Each parent contributes half of the DNA to create one complete set of DNA.

Therefore, the best answer choice is B. one strand of new chromosomes or half of the new organism's DNA.

answer: b

coz red blood cells marrow and circulates the body for 120 days.