Bio1110 Reproduction

Gametic meiosis

the production of haploid gametes, diploid cells undergo meiosis and become haploid

What does it mean to be oogamous?

an organism reproduces asexually using two different types of gametes, and egg and a sperm

Oogamy cells

egg cells and sperm cells

What are gonads?

primary reproductive organs that both produce gametes and secrete sex hormones, testes and ovaries

What is fertilization?

the union of gametes (plasmogamy and karyogamy)

Through sexual reproduction offspring are …

unique through genetic variation

Some animals can also reproduce how?

asexually

Egg cells are large and …

stationary

sperm cells are small and …

can move around, they have a small flagellum for movement

Fertilization is what kind of event?

a timed one that requires communication

External fertilization

both types of gametes are released into the environment, and swimming sperm cells are attracted to egg cells through hormones

Internal fertilization

solves the terrestrial problem for swimming sperm, gonads and accessory organs for copulation

testicle includes the …

scrotum and the testis

Vas deferens

the muscular duct, how sperm leave the testicle during ejaculation

Epididymis

where sperm finish development and become motile, its 6 meters of tubing and takes 3 weeks for the sperm to travel all 6 meters

Seminiferous tubules of testis

where sperm begin development, takes 7 weeks to develop here

Sperm follow what path to leave the reproductive system?

they start in the seminiferous tubules, then they go through the epididymis, then the Vas deferens, then the ejaculatory duct, and lastly the urethra

Spermatogenesis

development and maturation of sperm cells

The hypothalamus produces a hormone, GnRH that signals to the anterior pituitary to produce …

LH (Luteinizing hormones) and FSH (follicle stimulating hormone)

LH is recognized by what cells?

Leydig cells, tells them to produce testosterone

Testosterone promotes …

spermatogenesis

FSH signal what cells to nourish developing sperm cells in spermatogenesis?

Sertoli cells, they also make inhibin FSH, which is a hormone that goes back to the anterior pituitary to slow the production of FSH

Testosterone also goes back to the hypothalamus to inhibit the production of …

more testosterone and FSH

Males constantly produce sperm once they reach puberty, inhibin-FSH and testosterone maintain …

a steady amount of sperm production

Why are the testes found in the scrotum?

because sperm production requires the temperature to be 2-4 degrees cooler than the rest of the body, and the scrotum provides the cooler setting

What is semen?

sperm + secretions from seminal vesicles, prostate gland, and bulbourethral gland, contains mucus, nutrients and buffering agents, material that helps sperm swim

Why does semen need a buffering agent?

because the urine passes through the same erectile tissue so this helps keep it “sanitary”

Know which organs are which