A.vibrates with the frequency of the received sound
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.
Endangered species are going to be extinct if they don't get help. An endangered species is considered to be in more immediate danger of extinction than a threatened species. Threatened animals are considered at risk...
Chemotherapy is a process of intense treatment for cancer. It includes one or more anti-cancer drugs. However, most people become sick after they go through with chemotherapy. This can last for days or longer. Hopefully, nobody gets cancer and has to go through this procedure.
The species likely living in an ecosystem on the other side of the mountain farthest from the coast is the cactus.
- Cacti are evergreen plants. Their stems might be meaty or succulent, cylindrical or flattened.
- The stems are green in colour and photosynthetic, usually fulfilling this job instead of leaves, which are scarce or nonexistent in most adult cacti.
Most cactus species are well-defended by spiky bristles and spines that repel most animals.
- Cacti are xerophytic plants, which means they are physiologically and morphologically suited to the high water shortages of dry ecosystems like deserts.
- Cacti's xerophytic adaptations include (1) succulent, water-retaining stems, (2) a thick, waxy cuticle, and few or no leaves to decrease water losses through transpiration.
Learn more about cactus here,
brainly.com/question/16636755
# SPJ9
