Answer: Option A
Explanation:
Birds attach the bur of the plant which helps in the pollination. The birds sit on the plant and the burs of the plant gets attached in the legs of the birds which is transferred from one place to another.
Seeds at a different place will help in reproduction and growth of the plants. In this case the birds are carrier of the burs.
This is how the birds help in the reproduction of the plants by becoming the messenger.
Crossing over is termed as a process by which genetic materials are exchanged by non-sister chromatids during meiosis.
Crossing over results in the new combination of information in genetic for, the cell for a specific trait.
It ensures that organisms are identical from one generation to another. Genetic recombination allows variations in genetic materials which are passed through generations.
Answer:
They provide the body with energy.
Explanation: