Answer:
Genetic drift
Explanation:
Genetic drift is defined as the random change in allelic frequencies from one generation to the other.
Genetic drift is an evolutionary mechanism in which the allelic frequencies in a population change through many generations. Its effects are harder in a small-sized population, meaning that this effect is inversely proportional to the population size. Genetic drift results in some alleles loss, even those that are beneficial for the population, and the fixation of some other alleles by an increase in their frequencies. The final consequence is to <u>randomly</u> fixate one of the alleles. Low-frequency alleles are the most likely to be lost. Genetic drift results in a loss of genetic variability within a population.
Genetic drift has important effects on a population when this last one reduces its size dramatically because of a disaster -bottleneck effect- or because of a population split -founder effect-.
Answer:
A = Activator
B = Effector
Explanation:
An activator is a protein which typically binds to a short (50–1500 bp) region of DNA which might be located either upstream (mainly) or downstream of a gene so as to cause increased transcription. This particular region of DNA is known as enhancer and activator is also known as transcription factor. Activator is a trans-acting factor which binds to the cis-acting factor which is enhancer so as to enhance transcriptional expression.
But another protein named as effector may restrict activator from binding to the enhancer leading to a decrease in transcriptional expression by binding to the activator allosterically. Allosteric binding of effector to the activator causes conformational change in activator so it can no longer bind the enhancer.
A I think I hope this helped
Answer:
Arteries transport blood away to the different parts of the body from the heart. Arteries are the largest blood vessels in the whole body with elastic walls.
Hence arteries match with carries blood away from the heart and largest blood vessel in diameter
Capillaries take blood from various parts of the body. It exchanges nutrients, oxygen, and waste with tissues or cells. These are the smallest blood vessels.
Hence capillary matches with exchanges nutrients with tissues and single walled.
Veins transport the blood to the heart from the body. These vessels have a thin endothelial layer.
Hence Vein matches with carries blood to the heart and has a thin endothelial layer.
