Animal Reproduction

What is asexual reproduction?

1. The production of genetically identical offspring from a single parent

2. mitosis

3. Examples: Bacteria and Starfish

What is parthenogenesis?

parthenogenesis is the development of an egg into an embryo without fertilization. (Asexual reproduction)

What is sexual reproduction?

Reproduction involving 2 parent organisms combining genetic material to create diverse offspring.

What is oviparous?

Eggs hatch outside the mother's body. It requires yolk to support development.

(e. birds and reptiles)

What is ovuliparity?

aquatic reproduction in which eggs are released and sperm fertilizes them in the water. (ex. frogs)

What is ovoviviparous?

eggs hatch inside body (ex. seahorses)

What is viviparous?

organisms give birth to live young (ex. humans)

In humans, how soon after an egg is release must it be fertilized?

~24 hours

How long do embryos develop in fallopian tubes before embedding in uterus?

6 days

What type of hormone is measured for a pregnancy test?

human chorionic growth hormone (hCG)

What is a morula?

solid ball of cells

What is a blastocyst?

hollow ball of cells

What is a gastrula?

multi-layered embryo (endoderm, mesoderm, ectoderm)

What is an ectoderm?

"outer" "skin"

Gives rise to skin, nervous system, hair, and teeth

What is the mesoderm layer?

Middle layer, forms blood supply, muscles, & bones (organs in general)

What is the endoderm layer?

inner lining of digestive tract and respiratory system

What is the first organ system to develop?

central nervous system

When does an embryo heart start beating?

5th week

When does an embryo's organs all function?

10th week

Why are human babies born so early in development?

Because mothers can't support the baby metabolically

How many weeks must a fetus be to be viable outside the womb?

22 weeks

What has to occur for a couple to be considered infertile?

if a couple failed to achieve pregnancy after one year of regular unprotected sex

What are the primary causes for male and female infertility?

a. Male infertility normally due to low sperm count and/or a large number of abnormal sperm.

b. Female infertility is influenced by age, weight and hormone levels.

What is IUI (intrauterine insemination)?

Female injects hormones to make the body ovulate and the male sperm sample is cleaned and injected past the cervix into uterus

What is IVF (in vitro fertilization)?

The egg is fertilized outside the woman's body and then implanted back into her uterus.

What is GIFT (gamete intrafallopian transfer)?

Sperm and egg mixed outside the woman's body and then placed into the oviduct immediately.

What are some pregnancy issues?

a. ectopic pregnancy (egg is implanted in fallopian tube)

b. Placenta Previa (placenta covers or partially covers the cervix)

Where does spermatogenesis occur?

testes

During spermatogenesis, what type of sperm cells is produced from the stem cells?

haploid cells (meaning it has 1/2 of DNA)

What is oogenesis?

production of female gametes (egg cells)

What type of feedback is used during child-birth?

Positive feedback, in order to produce oxytocin