Answer:
D.both A and B
Explanation:
because if there some option,like abcd and the letter d. is both a and b that is the correct answer.
Answer: DNA
Explanation:
A chromosome is a thread-like material with a long structure found in the cell nucleus. It mainly contains DNA and proteins. Due to the presence of DNA in chromosomes, it carries several genes.
The total number of chromosomes in human cell is 46: 44 are non-sex chromosomes while 2 are sex chromosomes
Answer:
C. Vaccination
Explanation:
vaccination is the administration of a vaccine to help the immune system develop protection from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism.
Answer:
Natural selection is least likely to occur in this population if:
- The resources are continuously available
For a species to survive in an area, it is essential that the place has enough resources like nutrients, space, water etc. If these resources are available then there will be less chances of competition which will lead to lesser chances of natural selection.
- The number of of death rates is equal to the number of of birth rates
In an balanced ecosystem, the number of birth rates is equal to the number of death rates for a population. If the number of death rates is lesser to the number of birth rates then the competition for resources will lead to natural selection.
