4. Which of these components are found in the cells of all living organisms? A. estrogen and testosterone B. hemoglobin and lymphocytes
C. cytosine and guanine
D. cellulose and chlorophyll

C. cytosine and guanine

Explanation:

A.estrogen and testosterone - estrogen and testosterone are found in many mammals, but are not found in, for example, plants or bacteria.

B.hemoglobin and lymphocytes  - hemoglobin is a protein found in a red blood cells. Lymphocytes white blood cells Again, they are found in organisms with closed circulatory systems and immune systems, but not simple organisms such as insects.

C. cytosine and guanine  - these are the building blocks of DNA, which is a component in all living cells. Therefore, they are found in all living organisms

D.cellulose and chlorophyll - cellulose and chlorophyll are specific to plant cells.

"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."