Ques:Q: Plant-like protists produce oxygen through which process? Read this paragraph and choose the correct option from the provided answers: Plant-like protists are essential to the ecosystem. They are the base of the marine food chain, and they produce oxygen through photosynthesis for animals to breathe. They are classified into a number of basic groups ( Table below ). Choices: - respiration - metamorphosis - glycolysis - photosynthesis A:

Ans:photosynthesis
-----
Ques:Q: Lacking blood vessels, nerve endings, or glands, the epidermis is the outer layer of what? Read this paragraph and choose the correct option from the provided answers: The epidermis is the outer layer of skin. It consists almost entirely of epithelial cells. There are no blood vessels, nerve endings, or glands in this skin layer. Nonetheless, this layer of skin is very active. It is constantly being renewed. How does this happen?. Choices: - liver - brain - lungs - skin A:

Ans:skin
-----
Ques:Q: Which theory explains how populations of organisms can change over time? Read this paragraph and choose the correct option from the provided answers: The theory of evolution by natural selection explains how populations of organisms can change over time. As environments change, so must the traits of organisms if they are to survive in the new conditions. Evolution by natural selection explains how this happens. It also explains why there are so many different species of organisms on Earth today. You can see examples of the incredible diversity of living animals in Figure below . You can read more about the theory of evolution in the chapter Evolution. Choices: - free by natural selection - changes by natural selection - intelligent selection - evolution by natural selection A:

Ans:evolution by natural selection
-----
Ques:Q: What explains why two different species cannot occupy the same niche in the same place for very long? Read this paragraph and choose the correct option from the provided answers: A given habitat may contain many different species, but each species must have a different niche. Two different species cannot occupy the same niche in the same place for very long. This is known as the competitive exclusion principle . If two species were to occupy the same niche, what do you think would happen? They would compete with one another for the same food and other resources in the environment. Eventually, one species would be likely to outcompete and replace the other. Choices: - evolution - natural selection - survival exclusion princple - competive exclusion princple A:

Ans:
competive exclusion princple
-----