You have to measure the distance between them
The male
human has a sperm cell and the female has an egg cell. The cells from the male
and female that combine to form a zygote are called gametes. The human sperm
and egg cells each contain 23 chromosomes. . A combination of gametes forms a
zygote with 46 chromosomes. The type of cell division that produces gametes
with half the normal chromosome number is the meiosis. Meiosis is the type of
cell division used in sexual reproduction. It will occur in the testes and
ovaries.<span>Chromosomes get
shuffled when eggs and sperm are made. Though most adult cells contain two sets
of chromosomes, sperm and egg cells are different. These special cells have
just one chromosome from each pair. Which chromosome they get from each pair is
random, making each sperm or egg cell unique. There is also a bit of mixing
before the chromosomes are sorted into individual sperm or egg cells.
Chromosomes from each pair in a mother or father, respectively, make contact
and exchange pieces of DNA, creating hybrid chromosomes. </span>
When a mutation has an effect that helps a species adapt to an environment, and specimens of both genders have it, it will end up taking over, causing evolution to gradually happen.
Answer:
Pupillary light reflex refers to the contraction that the pupils present when they light up. In cases of injury to the optic nerve, when the eye where the injured optic nerve is illuminated, since it cannot conduct the stimulus to the brain, neither pupil closes.
Explanation:
Pupillary light reflex refers to the reaction that causes the pupil to close with light thanks to the contraction of the sphincter of the pupil and to open in the dark thanks to the relaxation of that muscle by not receiving any stimulus. A light stimulus reaches the eye and in the retina it is transformed, through a chemical reaction, into an electrical stimulus that will be transmitted through the optic nerve and the visual pathways to the brain. The visual cells of the retina, rods and cones, also act as light receptors that control the pupil's motor activity. Thus, pupil-motor thresholds to light follow the same spectral sensitivity deviations as visual thresholds, which are a function of the state of light adaptation of the retina.
