2. What do all echinoderms have in common? A. None of them can move.

B. They have tiny, tube feet.

C. They have an exoskeleton.

D. They breathe air with lungs.

Arafura file snakes are large, aquatic, non-venomous snakes found in the flood-plains of australian rivers. they feed only on fish found in the rivers. it has been observed that heavy rainfall in the wet season in one year leads to prolonged inundation of the floodplains lasting a year or longer. it has also been observed that these snakes remain in good physical condition after a flood. explain how the file snake population in a region is likely to be affected by the prolonged inundation of a flood-plain.

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim