What is the difference between selective and cross breeding​

What causes an unsaturated fatty acid to have a different shape than a saturated fatty acid? o a. unsaturated fatty acids have more hydrogen atoms. o b. unsaturated fatty acids have double carbon bonds. o c. unsaturated fatty acids have more nitrogen atoms. o d. unsaturated fatty acids have single carbon bonds.

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?