Answer:
I think that birds have different bill lengths because of their habitats and their diet. Also natural selection and evolution has also played a factor due to the fact that birds have not always looked the way that they do now, for example the Archaeopteryx a bird that lived around the time of the dinosaurs had a shorter and more powerful bill to grind insects and small mammals
Explanation:
Answer:
The correct ansqwer is- Vitamin D
Explanation:
Vitamin D is the vitamin that can be synthesized by the human body itself therefore it is not an essential vitamin for human beings. Human skin is the part that helps in making this vitamin in humans.
The natural form of vitamin D is vitamin D3 which is formed by the sunlight exposure on the skin. When we expose our skin in the sunlight the UV radiation penetrated our skin and converts provitamin D3 into pre-vitamin D3 then this previtamin can be isomerized into the natural form of vitamin D Which is vitamin D3. So the right answer is vitamin D.
Answer:
A new mutation
Explanation:
A mutation refers to the random changes in the DNA of organisms. A mutation changes the allele and genotype frequencies by the introduction of a new allele in the gene pool.
However, mutations are not the major factor responsible for changes in the gene pool of a population as mutations are rare. The rate of mutations is very slow and does not allow it to serve as a major factor to change the allele and genotype frequencies.
