Help please :)
Which organism fills a similar niche as this organism in a different ecosystem?

A. prairie dog
B. American pika
C. long-tailed weasel
D. lappet-faced vulture

Which element is used in photosynthesis found in atmosphere and fixed by bacteria?

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.