From a human point of view, a habitat is where you live. It might be your city, town, or neighborhood. Your habitat can be altered. Most people move a few times in their lives. But a plant cannot move. An animal may not be suited to live in another area. A habitat is the natural home or environment of an organism. Humans often destroy the habitats of other organisms. The loss of habitat can cause the extinction of species. Extinction is when a species disappears forever. Once a species is extinct, it can never be brought back. Humans cause habitat destruction in many ways. There are two common ways this happens. Land may be cleared. Another way is when an animal or plant is brought to an area where it does not belong.

Question: "What are the two common ways that habitat destruction can occur?"

Response: "Land being cleared & when an animal or plant is brought into an area it does not belong."

A: yes

Living things need non-living matter as well as energy. What do you think matter is used for? One thing is to build bodies. They also need it to carry out the processes of life. Any non-living matter that living things need is called a nutrient. Carbon and nitrogen are examples of nutrients. Unlike energy, matter is recycled in ecosystems. You can see how in Figure 3.11. Decomposers release nutrients when they break down dead organisms. The nutrients are taken up by plants through their roots. The nutrients pass to primary consumers when they eat the plants. The nutrients pass to higher level consumers when they eat lower level consumers. When living things die, the cycle repeats.

Question: "What do living things use non living matter for?"

Response: "Decomposition"

A: no

"What goes up must come down." You have probably heard that statement before. At one time this statement was true, but no longer. Since the 1960s, we have sent many spacecraft into space. Some are still traveling away from Earth. So it is possible to overcome gravity. Do you need a giant rocket to overcome gravity? No, you actually overcome gravity every day. Think about when you climb a set of stairs. When you do, you are overcoming gravity. What if you jump on a trampoline? You are overcoming gravity for a few seconds. Everyone can overcome gravity. You just need to apply a force larger than gravity. Think about that the next time you jump into the air. You are overcoming gravity for a brief second. Enjoy it while it lasts. Eventually, gravity will win the battle.

Question: "How can humans overcome gravity?"

Response: "Climbing stairs"

A:
yes