Exam 4 | Reproductive pt. 1

Question 1

What is the most common form of reproduction among organisms in the domain Eukarya?

Answer 1

Sexual reproduction

Question 2

What are the benefits for sexual reproduction?

Answer 2

• enhanced genetic diversity in a population
• selection for adaptations that enhance an organism’s fitness
• form close social connections with members of one’s own species
• establish a social hierarchy in a population

Question 3

What does the term sex refer to?

Answer 3

The term sex refers to the genetic/ biological factors that determine one’s reproductive anatomy. This term is used to describe reproductive anatomy and physiology in all organisms, including humans.

Question 4

What does the term gender refer to?

Answer 4

The term gender is used exclusively when discussing human sexual behavior and identity. This is unique to human’s and a social construct

Question 5

What are the 2 most important functions of the reproductive system?

Answer 5

1) to produce gametes (sperm in males & eggs in females)
2) to produce sex hormones (testosterone in males & estrogen and progesterone in females)

Question 6

Where is sperm produced and how often?

Answer 6

Sperm are produced in the testicles (testes) in males, and the production of sperm is governed by the presence of testosterone, which fluctuates on a circadian (24-hour) cycle.

Question 7

Where are eggs produce and how often?

Answer 7

Eggs are produced in the ovaries in females, and each female produces one egg per month, and the time at which the egg is produced (known as ovulation) varies by each individual’s menstrual cycle.

Question 8

How is the male reproductive system divided up?

Answer 8

By external & internal structures

Question 9

What are the external structures for the male reproductive system?

Answer 9

Penis & scrotum

Question 10

What are the internal structures for the male reproductive system?

Answer 10

Accessory glands, vas deferens, epididymis, and testes

Question 11

What’s the role of the testes?

Answer 11

the testes (testicles) are where sperm and testosterone are produced

Question 12

How many accessory glands are there and what are their roles?

Answer 12

there are three accessory glands which produce other glandular secretions/ fluids that help to protect and carry sperm throughout the reproductive tract.

Question 13

Where does spermatogenesis occur?

Answer 13

In the testes

Question 14

At what temperature should the testes stay at and why?

Answer 14

The testes should be kept at a relatively constant temperature of no more that 35 degree celsius in order to produce viable sperm

Question 15

When do the testes descend from inside the body?

Answer 15

At approximately 7 months of gestation, the testes descend from inside the body to the scrotum

Question 16

What is cryptorchidism?

Answer 16

This is a rare condition in which the testes fail to descend during development, and can lead to increased risk of sterility (infertility) and testicular cancer.

Question 17

Where is the specific site of sperm production?

Answer 17

The seminiferous tubules which are coiled structures found inside the testes; these tubules have 2 specific cells inside that aid in spermatogenesis

Question 18

What are the 2 cells that aid in spermatogenesis? What does each one do?

Answer 18

Sertoli & Leydig cells; Sertoli cells are most closely associated with spermatogenesis while Leydic cells are mainly aiding in testosterone production which is necessary for stimulating spermatogenesis as well as maturing the spermatozoa

Question 19

Why is testosterone considered to be an androgen?

Answer 19

It’s a steroid hormone associated with males

Question 20

Why is testosterone’s aid in production of estrogen important?

Answer 20

It is particularly important for the masculinization of the brain during development.

Question 21

Describe the feedback loop of testosterone.

Answer 21

It both inhibits the release of GnRH, FSH and LH, as well as stimulates the production of sperm in the seminiferous tubules by binding to its receptor(s) on Sertoli and Leydig cells.

Question 22

Define spermatogenesis.

Answer 22

It is the process of producing new spem cells; specifically at the seminferous tubules

Question 23

What process is spermatogenesis most similar to?

Answer 23

It involves a single round of mitosis followed by a single round of meiosis

Question 24

Describe the step by step process of spermatogenesis.

Answer 24

1) The first cell to be produced (or rather, copied) is the spermatogonium, which is an undifferentiated diploid (2n) cell. These spermatogonia undergo a single round of mitosis to produce the primary spermatocyte.

2) After the primary spermatocyte is produced, this cell undergoes Meiosis I to produce two haploid (1n) cells known as secondary spermatocytes.

3) These secondary spermatocytes further divide in Meiosis II to produce four haploid (1n) cells known as spermatids.

4) Finally, the process of differentiation (which requires the presence of chemical cues, including sex hormones) produces the mature spermatozoa (sperm) cells which exhibit the necessary morphology (most notably the flagellum) to swim and fertilize an egg.