Answer:
Option 1.
Explanation:
r-selected species may be defined as the species that has higher growth rate, shows less parental care and the rate of survival of the off spring is low as compared with k selected species.
Black widow spiders have the ability to produce 1000 offspring. Their chances of survival are extremely low and only few species of black widow spiders survive. Hence, black widow spider is r-selected species.
Thus, the correct answer is option (1).
Answer:
1. Slash and Burn agriculture refers to a technique of farming that requires plants in a forest or woodland to be decimated to create a cultivable expanse of land.
Some of these plants are usually homes to wild chimpanzees. The more they are cut down, the deeper into the forests they would migrate, that's if they ever find a place like it.
2. When compared to the other primates such as monkeys, baboons, etc their larger body size, puts them at a disadvantage. This is because when they are placed in a restricted space, they need more food which in turn translates to increased height and weight.
Cheers!
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.
Skeletal muscles have an abundant supply of<span> blood vessels and nerves.</span>
