The OLFACTORY AND THE GUSTATORY SYSTEMS have receptors which die out after sometimes because of direct exposure to the environment.
The olfactory system has to do with the perception of smell while the gustatory system has to do with taste stimuli. For these two basic sense organs, their perception rate is always highest when they are newly exposed to a stimuli, after continuous exposure to the stimuli their receptors die out.
Answer:
The options
A) "Medications are needed to prevent heart failure."
B) "I will take aspirin, atenolol, and captopril indefinitely."
C) "My blood pressure should be less than 130/80 mm Hg."
D) "Daily estrogen will prevent another heart attack."
The CORRECT ANSWER IS D)
D) "Daily estrogen will prevent another heart attack."
Explanation:
A reduction in the natural hormone estrogen levels could be a causative factor in heart disease increase within post-menopausal women. Estrogen is thought to show a positive impact on the inner layer of artery wall, functioning in such a way to keep blood vessels elastic.
In spite of the advantages of estrogen, the American Heart Association speaks against employing postmenopausal hormone therapy to decrease the likelihood of coronary heart disease or stroke as some research works have revealed that it vividly do not decrase the risk of heart attack but increases the likelihood of blood clots and stroke.
Answer:
Environmental factors can influence natural selection because they can increase or decrease the amount of genetic variation in a population.
Explanation:
Natural selection is a process that involves the survival of species through changes in the expression of their genes, making possible the process of adaptation to environmental changes. It is one of the explanations for the biological evolution of species.
The second premise, necessary for natural selection to be possible, implies the existence of a variability (genetics) of traits among individuals in a population.
The other premises of natural selection are the faculty of traits to be inheritable and that genetic variability should lead to reproductive success and survival.
- <em>The other options are not related to the process of natural selection, since it is not possible for natural selection to increase or decrease the number of chromosomes, in addition to the fact that genetic variability must be observed in a population, not in a single individual, to be considered natural selection </em>
Answer:
Negatively repressible.
Explanation:
A control which occurs through repressor is known as negative control which may be inducible or repressible.
When a small molecule named as allolactose binds this repressor it leads to allosteric repulsion which removes repressor from the operator as a result of which RNA polymerase can start transcription. Allolactose is therefore known as inducer because it induces lac operon expression.
But here, the operator is active (induced) already so there is no need to induce the operon which means that it can only be repressed so that transcription could stop. So the answer is negatively repressible operon.
Answer:
When the oxygen atoms of different water molecules come together, they repel. When the hydrogen atoms of different water molecules come together, they repel.
Hope this helps
