Answer:
Mutations in the HBB gene cause sickle cell disease. The HBB gene provides instructions for making one part of hemoglobin. Hemoglobin consists of four protein subunits, typically, two subunits called alpha-globin and two subunits called beta-globin.
Explanation:
Answer:
Energy decreases as it moves up trophic levels because energy is lost as metabolic heat.
Explanation:
When the organisms from one trophic level are consumed by organisms from the next level. ... A food chain can usually sustain no more than six energy transfers before all the energy is used up.
Answer:
A. Migration
Explanation:
Migration is one of the evolutionary forces that change the allele frequencies of the population. Migration refers to the movement of individuals from one population to another. As the individuals move out of a population, transfer of alleles also takes place. When the immigrated individuals interbreed in a new population, they add new alleles to the gene pool of that population.
In the given example, 200 garter snakes moved out of the population resulting in changed allele frequency of the original population. Since the changed allele frequency was due to the movement of snakes, it represents migration.
Answer: Option B
Explanation:
The male sparrow does not takes care of the baby sparrow. Such kind of baby sparrow's has very less chances of survival and fledging. They die before this stage due to lack of parental care.
Generally the female sparrow takes care of the baby sparrow and the males fly away. They get involved in mating with the other female sparrow and fathering more eggs.
Hence, the correct answer is option B.
D. Predators
Predators keep populations of other species in check. This was pretty clearly demonstrated in Yellowstone National Park after the wolves were eradicated there. The deer populations increased to the point that the aspen trees nearly disappeared due to the saplings' being eaten by deer. Since the reintroduction of wolves to the park, the aspen trees have begun to flourish once again.