BIO: Chapter 18 (pt 1) Gametes, Male Sexual Reproductive System

Meiosis

When diploid cells divide and you start with a diploid cell and end up with a haploid cell. Known as a reductional division because the number of chromosomes have to be reduced as the cell divides.

Testicular Vein

"Pampiniform Plexus"

Chromosomes and Parents

A full-diploid of chromosomes is 26,

Alleles

Variations of genetic traits, hair color, eye color, height, skin color.

Seminiferous Tubules

(Sperm Tubes) Actual site of sperm production within the testes. Organized into lobules

Somatic Cell

Body cells like skin blood and liver

Vas/Ductus Deferens

Carries sperm from epididynus to inside of body at the time of ejaculation/orgasm. 50cm

Testicular Nerves

Collect sensory information from area to stimulate muscles to contract

Testicular Artery

Delivers oxygen and nutrient rich blood to the testes

Nondisjunction

Duplicated chromosomes don't separate during the process of Meiosis. So instead of each of the gametes having 22 gametes, one might have 24 because they didn't separate.

Zygote

First cell of the new individual when sperm and egg combine. Diploid cell, 2N, 1st cell of potential new organism.

Meiotic Division

First division separates duplicates

Fertilization

Gametes meet and combine genetic material (chromosomes) by ONE sperm cell penetrating the egg cell. The process of meiosis randomly sorts and packages the genetic materials.

Mitosis

How we get skin cells, much simpler than meiosis because you just go from a parent diploid cell creating two identical diploid daughters.

Gametes Slide

In the male, meiosis occurs and four sperm are produced from two divisions of a primary spermatocyte Females produce only one egg from each round of meiosis, investing almost all of the cytoplasm and organelles in one gamete During meiosis, chromosomes are brought into close contact with one another - this contact allows them to exchange alleles, further increasing genetic variation The process of (homologous) chromosomes exchanging segments and alleles is called crossing over

Sertoli Cell

Isolate developing sperm, nourish and protect them from the immune system.

Leydig /Inters

Make testosterone and you will find them between the spermtubes

Testicular Torsion

Occurs when a testical rotates, twisting the spermatic cord. Blood flow reduces, causes pain, most comment from 12-16. Must be reversed in LESS THAN THREE (3) HOURS or can cause permanent damage.

Duct

Passageway

Karyotype

Picture of chromosomes

Fertilization

Process where gametes meet, combine genetics/chromosomes. Male sperm N meets Female egg N to make 2N cell and create full 3 of chromosomes.

Gametes

Sex cells (sperm+egg). It's important that they be haploid (1/2 the full number of chromosomes), also known as N-Number (N#). Cells come from cells but their process is different from regular cell division. Uses Meiosis.

Sexual reproduction requires two genders to perpetuate the species Males contribute sperm Females contribute eggs Fertilization combines a sperm and an egg to produce the first cell of the new individual (the zygote) Fertilization mixes and blends the alleles in the gene pool, creating new genetic combinations, which leads to genetic variation These new genetic combinations are essential to the survival of the species The genetic variation within populations of sexually reproducing organisms is the basis for adaptation of organisms to their environment "More fit" individuals will produce more offspring, thereby increasing the percentage of their alleles in the gene pool

Sexual Reproduction Happens in two steps, males contributing sperm, females an egg. Combine to make Zygotye

Gametogenesis

The process that is the forming of gametes.

Spermatic Cord

The spermatic cord is much like an electrical cord containing multiple wires Located within the spermatic cord: Vas/ducuts deferens Testicular artery Testicular vein Arranged as the pampiniform plexus Lymphatic vessel Nerves