Amino acids arë Fequired for the synthesis of p biosynthetic pathways to synthesize at least proteins. S while other E. coli strains cannot eukaryote, can synthesize tryptophan, while other S. cerevisiae strains cannot roteins. Living cells typically have some of the amino acids used in making J4. ome strains of E. coli, a prokaryote, can synthesize the amino acid tryptophan, . Similarly, some strains of the yeast S. cerevisiae, a hich of the following describes the most likely source of genetic variation found in the tryptophan synthesis pathways of both species? a. Exchange of genetic information occurs through crossing over b Viral transmission of genetic information required to synthesize tryptophan occurs c. Random assortment of chromosomes leads to genetic variation d. Errors in DNA replication lead to genetic variation

d. Errors in DNA replication lead to genetic variation is the correct option.

"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."

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.