What is a niche? as in related to biology?

Suppose you are estimating the size of a blue crab population. what is the population size if the number marked in the first catch is 40, the total number in the second catch is 200, and the number marked in the second catch is 50?

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.

7. describe two strategies that parents can use to cope with stress. 8. describe the three types of childcare available to families. 9. what can parents do to be more involved in their children's education at home and at school? 10. which factors should a parent consider when choosing a childcare option?