)Sexual reproduction maintains a constant level of variation in the population and requires less energy.
Fission reaction in sun..
<span>Letter A is the answer. Almost all plant cells have single large central vacuole. These large central vacuoles of the plant cells are filled with water and can take over 80% of its cell volume. This is surrounded by a single membrane called tonoplast. The role of the central vacuole is maintaining the plant cell's pressure.</span>
Polygenic traits are those traits that are controlled by more than one gene. Such traits may even be controlled by genes located on entirely different chromosomes. Human height, eye and hair color are examples of polygenic traits. Skin color is another polygenic trait for humans and a variety of other animals
Convection currents are caused by the colliding of cold and warm air. At night, air above water is warm and air above land is cold. The opposite is true in daytime. When the warm air hits the cold air, which is more dense, it is pushed upward. Then it travels laterally until it cools. It comes back down and pushes up the former cold air, which is now warm. This repeats many times.