The appropriate answer is D. Alfalfa. Alfalfa is a legume and these plants play a key role in the nitrogen cycle. These plants house nitrogen fixing bacteria on their roots. The bacteria are housed in tiny round structures of leguminous plant roots. Once the nitrogen is fixed in the soil it can now be used by other plants to make food. These plants include beans peas and peanuts. <span />
B. Eukaryotes have membrane-bound organelles. Prokaryotes have few special structures
Im not 100% sure but i want to say main sequence stars
Explanation: Elephants have been extensively hunted for ivory for more than 300 years, natural selection is often proposed as the underlying mechanism for an increase in the proportion of tuskless or small-tusked elephants in a population.
Answer: The first and the fourth figure is showing the two stages of metamorphosis in beetle. The first figure represents the adult stage of beetle and the last figure represents the larvae stage of beetle. Metamorphosis is the biological process by which an organism goes through differentiation of cells. As a result of this differentiation the structure of the organism changes from one to another. There are four stages egg, larvae, pupa, adult.
The second figure shows regeneration in cnidaria. They repair their body and reproduce asexually by this process. They show two stages polyp and medusae. Medusae have less ability to regenerate but poly stage can regenerate from small parts. This ability helps corals to heal back after being destroyed by predators.
The third figure represents cow and this is an unique feature of mammals to produce milk by their mammary gland. During the lactation period the cow produces milk that is used by cattle and human beings.
