1. Materials of biological origin which is commonly used to maintain soil fertility is
A. bordeaux mixture.
B. suphala.
C. compost.
D. urea.

compost

Explanation:

Among the choices mentioned above, it is only "compost" that is biological in origin. That's because it came from organic waste products that were decomposed; thus the name "compost."

Compost consists of essential nutrients (phosphorus, nitrogen and potassium) ideal for fertilizing the soil. This is often added to the soil and used in gardening and farming. It also aids in plant's immunity by resisting plant diseases.

answer; i do believe that the correct answer is; ///mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis;

"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."