How many embryonic and adult tissue layers are found in jellyfish, hydras, and sea anemones?
a. 1
b. 2
c. 3
d. 4
a. specialized vascular tissue.
b. absorption alone.
c. absorption and transpiration.
d. osmosis and diffusion.

Malthus studied limited resources and the impact of limited resources on human populations. how did these ideas contribute to darwin's ideas? a. limited resources in an environment means that the individuals of a species cooperate so that all individuals survive. b. limited resources in an environment forces some individuals to survive without food. c. limited resources in an environment means that not all individuals of a species will survive or reproduce at equal rates. d. limited resources in an environment forces more genetic changes in individuals, allowing the species to evolve more quickly.