Clam shells such as the one shown in the photograph build and shape
structures by providing the nutrients necessary to form reef frameworks.
other organisms in the ecosystem depend on these structures. which term
best describes the clam's role in its marine habitat?

a. biotic factor

b. abiotic factor

c. protist

d. producer

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?

Type the correct answer in the box. use numerals instead of words. fiona has a lovely flower bed in her yard. she wants to add a fence along one side of the flower bed. the fence material is sold in meters. fiona knows that her flower bed is 200 centimeters in length. how much fencing material does fiona need in meters? fiona needs meters of fencing material for her flower bed.

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays