D. cellular respiration and photosynthesis
<span>Temperate Decidous Forest.. </span>
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.
Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads, and exchange DNA. The nucleolus and nuclear envelope disappear.
Answer:
The answer is B, extensive research of an individual organism over many years.
Explanation:
The question is asking, what best describes Darwin's studies that led to the theory of evolution, it would be a lot of research over a long period of time. Think, if you were to do a school project, would you get your best results over a short or long period of time with little or a lot of evidence/research? So, B is the best answer, I believe.
(PLEASE BRAINLIEST)