The hen. The hen came fist in order to lay the egg. God just the hen on earth
a. 2 > The 23rd pair, the sex chromosomes, differ between males and females (females have two copies of the X chromosome, while males have one X and one Y chromosome). In humans, the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. The other 22 pairs of chromosomes are called autosomes. <em>Chromosomes are thread-like molecules that carry hereditary information (they are made of protein and one molecule of DNA, which contains an organism's genetic instructions).</em>
OA) sugars and phosphates; nitrogen bases
Half, because the ovum from the mother and the sperm from the father fuse together to form the zygote which will develop into the new human being, and the ovum and sperm, being gametes, each have half the number of chromosomes that you usually find in somatic cells (any other cell in the body that is not a gamete).
Because their bodies tell them that they need more oxygen and so breathe faster, and try and get the oxygen their body requires and depends on.
