A motor unit is defined as an axon and all of the: 1. muscle fibers that the branches contact 2. sarcomeres that its dendrites 3. contact fascicle that the branches contact.

Correct answer is Option 1. muscle fibers that the branches contact.

Explanation:

A motor unit is made up a motor neuron also known as an axon and the number of muscle fibers that the branches have contact with.

Motor units function in such a way that they organise the contractions of one muscle when they receive a signal from the brain.

Motor units can come in

a. Large sizes : an example is the muscle in the limbs

b. Small sizes: an examples is the muscle in the eyes

"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 menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.