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.
Answer: probability that both twins are affected is 0.0625 while the probability that both twins are unaffected is 0.5625
Explanation:
If both parents are heterozygous for albinism, it means they both have one recessive allele (Aa) each.
The possible genotype outcome of one child will be
AA Aa Aa aa
Therefore the possiblility one child will inherit both recessive allele (aa) is 1/4 and the probability that one child is unaffected is 3/4
If the had a dizygoyic twins this means the two children have different DNA.
So also the possibility of the second child to inherit both recessive allele (aa) is 1/4
The probability that both the twins are affected is
1/4 * 1/4 =1/16 = 0.0625
The probability that both are unaffected is
3/4 * 3/4 = 9/16 = 0.5625
A) divergent boundary
B) convergent boundary
C) transform boundary
Add moko adrian depla pre tytor
Answer:
Directional
Explanation:
In population genetics, for natural selection to occur there must be a variation that will favor the survival of an individual.
Directional selection is a form of natural selection that occurs in the extreme end when an environment condition such as food favors one phenotype over the other.
This will make the allele Frequencies to shift towards the direction of the superior phenotype.