These structures are found in both plant and animal cells. They are mitochondria.
Respiration takes place inside them.
Some cells have more mitochondria than
others. Which would you expect to contain
most mitochondria: muscle cells or skin
cells? Explain why.

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Choose the molecule that is described by each phrase. energy used during long activities:

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?