Acactus with long spines protects itself from animals better than a cactus with short spines. according to natural selection,

1. short-spined cacti will survive longer and reproduce more often than
2. long-spined cacti long-spined cacti will survive longer and reproduce more often than short-spined cacti
3. over time, the population will become entirely made of short-spined cact
4. over time, cacti with long spines will completely die out

2. or B.

long-spined cacti will survive longer and reproduce more often than short-spined cacti.

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."