What best describes a Gene pool

Which of the following is a cost of urbanization? a-cities can provide a high standard of living. b-cities are hubs of entertainment and education. c-paving over land changes the environment. d-job opportunities are greater in urban centers.

Name the plastid and pigment likely to be found in the cells of (a) petals of sunflower (b) ripe tomato.

What kinds of molecules can pass through the cell membrane without any problem?