Time as a word, or time as a construct?
Answer:
The correct answer is b. must be present in a population before natural selection can act upon the population
Explanation:
Genetic variation can be caused by mutation, recombination between chromosomes during meiosis and by fusion of two genetically different gametes during sexual reproduction.
This genetic variation is necessary for the evolution of any population. Natural selection acts on every individual and it decreases the frequency of those alleles that are not suited for the environment and increase the frequency of those alleles which helps the individual to survive in the changing environment.
Therefore genetic variation must be present in the population before natural selection act on the.
During exercise, there is an increase in total blood flow due to a faster and stronger heartbeat and because blood is removed from the “reservoirs” of the veins to the active circulation. There is also a redistribution of blood. In contrast, less total blood flow is distributed to the abdominal organs, slowing digestive processes; less is transported to the kidneys, which decreases urine output to maintain blood volume and blood pressure.
Answer:
Microbial control agents can be described as agents which will inhibit or prevent the growth of microbes. Hence, they will prevent the damages caused by microbes.
Microbial control agents can either inhibit the growth of microbes. In this way, the population of the microbes will not expand and hence, the effect of the microbe on a host will be controlled.
Other microbial control agents kill the microbes and hence, control the effect of microbes.