GN 301 Module 2: Gametogenesis, Nondisjunction, Fertilization, and Early Development

Placenta

an organ in the uterus that nourishes the embryo, develops 2 weeks after fertilization, created by both the fetus and the mother.

Implantationis

the stage where the embryo attaches to the uterus and forms the placenta.

hollow center

The lumen is the ________ of the tubule where formed sperm are released into the the duct system.

Fertilization

when male sperm penetrates a female egg, which join together.

Syngamy

where the nuclei of the egg and the sperm fuse to form a zygote (4- 5 hr after fertilization)

HCg

Human Chorionic Gonadotrophin, which is a hormone produced during pregnancy that helps support an embryo and stops menstruation.

Amnion

the inner membrane surrounding embryo, created by the fetus.

Gametes

can be produced with abnormal chromosome numbers sometimes.

Chorion

outer membrane surrounding embryo, created by both the fetus and the mother.

uterus

where a fertilized egg is implanted during pregnancy, where a baby will develop until birth.

Females

born with about 1 million egg cells that are in the prophase I stage of meiosis.

largest cell

An egg is the ________ in the human body.

cilia help

The ________ push the immobile fertilized egg into the Fallopian tubes after fertilization.

epididymis

a coiled structure that receives immature sperm and stores it for several days.

Amnion

the inner membrane surrounding embryo, created by the fetus

Chorion

outer membrane surrounding embryo, created by both the fetus and the mother

Spermatogenesis

Occurs in the seminiferous tubes of men

How long to make mature sperm?

9-11 weeks

How many sperm produced per week?

1 billion

Spermatogonium

**primary spermatocytes** 🡪 **secondary spermatocytes** 🡪 **spermatids** 🡪 **spermatozoa**

Polar Body

the small cell that is a byproduct of an oocyte meiotic division, which usually just disappears

What are consequences of nondisjunction?

Gametes are produced with abnormal chromosome numbers. If these gametes are fertilized, individuals can be born with an abnormal number of chromosomes which leads to genetic disorders.

Zygote

A cell that has been fertilized by 2 gametes

Embryo

An unborn offspring in the process of developing, up to 8 weeks

Fetus

An developing offspring 8 weeks after conception

Fallopian Tube (oviduct)

The tubes provide a passageway for a fertilized egg to make its way to the uterus.