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.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

When mendel crossed a true-breeding short plant with a true-breeding tall plant all the offspring were tall. which term describes the gene for tallnes?

When a person is exercising the body needs to deliver increased amounts of oxygen to the muscles which component of blood ensures that the muscles will receive it