Answer:
The correct answer is genetic drift.
Explanation:
The phenomenon of changing the frequency of an allele in a specific population with time is known as genetic drift. The mentioned gene variation or the modification in the frequency of the allele is required to take place abruptly so that the phenomenon of genetic drift can take place. The environmental factors do not play an essential role in the phenomenon of genetic drift to take place.
The process of genetic drift occurs generally due to random sampling of organisms, it illustrates the random change in the number of gene variants within a population. When the existence of the different forms of a gene, that is, alleles, enhances or reduces by chance with time within a population, the phenomenon of genetic drift occurs. Thus, the mentioned case is an illustration of genetic drift.
It is mostly likely the cell membrane.
The cell membrane is a structure of a cell composed of double layer of lipids and proteins. It surrounds a cell and separates the cytoplasm from its surrounding environment. The cell membrane is selectively permeable (semi-permeable), which means that it only lets certain molecules enter and exit. It can also control the amount of some substances that go into or out of the cell.
Neurotransmitters are the chemical molecules, which help in transfer of the signals from one neuron to another. Inside the neurons, the signals are transferred as electrical signals, but at junction of two neuron, which is known as synapse, the signals are transferred in chemical forms.
These neurotransmitters have a definite shape and are recognized by the receptors present in the receptor site of the succeeding neuron. The neurotransmitters from the synapse binds to the receptor site of the receiving neuron. binding of the neurotransmitter to the receptor causes excitation of the receiving neuron, which also known as postsynaptic neuron.
Hence, Like a key in a lock, the shape of the neurotransmitter must bind with the receptors of the receiving neuron.
Atherosclerosis refers to the build-up of fats and cholesterol in the walls of blood vessels (Option A).
<h3>What is atherosclerosis?</h3>
Atherosclerosis is a disease characterized by the build-up of fats and cholesterol in the walls of blood vessels.
This build-up of fats narrows the blood vessels, thereby difficulting the movement of blood in the bloodstream.
The symptoms of atherosclerosis include, among others, chest pain, shortness of breath and fatigue.
Learn more about atherosclerosis here:
brainly.com/question/4142223
Answer:
Seminal vesicle
Explanation:
Seminal vesicle secretes an alkaline and viscous fluid that constitutes about 60% of the volume of semen. The fluid secreted by seminal vesicle contains fructose which is a monosaccharide sugar, prostaglandins, and clotting proteins. The alkaline nature of the seminal fluid neutralizes the acidic environment of the male urethra and the female reproductive tract. This is required as the acidic conditions inactivate and kill sperm.
The fructose sugar serves a fuel for ATP production by sperm. Prostaglandins are responsible for sperm motility and viability as they stimulate smooth muscle contractions within the female reproductive tract. Therefore, a malfunctioning seminal vesicle would result in low semen volume and reduced motility due to the scarcity of energy.
