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27 Cards in this Set

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Mitosis
Cell's DNA divided to form two daughter cells that identical to the parent.
Interphase
Chromosomes are replicated, so a copy can be given to daughter cells.

DNA is uncoiled and called chromatin.

Individual chromosomes not visible.
Prophase
1. Chromosomes condense.

2. Centrioles seperate and move to opposite ends of the cell.

3. Nuclear membrane disslves.

4. Spindle fibers interact with chromosome.
Metaphase
1. Spindle fibers attach to each chromatid, and chromosomes align at center of cell.

2. That is the metaphase plate.
Anaphase
1. Centromeres split; sister chromotids seperate.

2. They are pulled to opposite ends of cell.
Telophase
1. Spindle appartus disappears.

2. Nuclear membrane forms around each set of chromosomes (2n chrom)

3. Chrom uncoil
Cytokinesis
Cytoplasm divides into two cells. Cleavage furrom forms, spliting the cell into two.
Meiosis
Sexual reproduction. It produces a haploid number of chromosomes (n). Four haploid cells form (gametes)
First meiotic division produces:
1. Two intermediate daughter cells

2. They have n chromosomes

3. Sister chromatids
Prophase I
1. Chromatin condense to chromosomes.

2. Homologus chromosomes (chrom that code for same traits, from dif parents) come together and intertwine at a point called the synapsis.

3. Sometimes chromatids of homologus chrom break and exchange DNA, this causes genetic variation.
Metaphase I
Homologus pairs (tetrads) line up in center of cell, and its kinetochore is attached to the spindle fiber.
Anaphase I
1. Homologous pairs seperate.
Telophase I
Nuclear membrane forms around each set of sister chromatids.
Second meiotic division
Very similar to mitosis

The new cells have a haploid number of chromosomes.

In women, only one (of the two) daughter cells become a functional gamete.
Asexual Reproductive Mechanisms
1. Fission - DNA replicates, new cell wall and membrane grow with equal amounts of cytoplams. (bacteria, amoebae)

2. Budding - replication of nucleus followed by unequal cytokinesis. New cell is smaller in size but genetically identical. (yeast)

3. Regeneration - Regrowth of lost of injured body part.

4. Parhenogenesis - development of unfertilized egg into adult. (In bees, males come from unfertilized egg and female come from fertilized).
Spermatogenesis
1. Occurs in seminiferous tubules.

2. Diploid spermatogonia produce four haploid sperm of equal size.
Oogenesis
1. Occurs in ovaries

2. One diploid primary female sex cell produces a sinlge mature egg.

Each meiotic divison produces a polar body, which is a small cell that only has a nucleus. These degenerate.
Male reproductive physiology
1. Testes are found in the scrotum.

2. Sperm go through the vas deferens from the testes, to the ejaculatory duct.

3. They go to the urethra next which leads out of the penis.
Primary spermatocytes
Two diploid cells formed from sprematogenia.


They go through the first meiotic division to form two haploid secondary spermatocytes.

The second meiotic division produces four haploid spermatids.

The spermatids undergochanges to form mature sperm, spermatozoa.
Female reproductive system
1. There are thousands of follicles (sac of cells that contain immature ovum) inside of the ovaries.

2. The follicle cells produce estrogen.

3. When the ovum is released once a month, it goes into the abdominal cavity and into the oviduct (fallopian tubes).

4. It then goes into the uterus.

5. The cervix connects the vaginal canal.
Primary oocytes
Immature ovum, all present at birth.

After meiosis I, two daughter cells of unequal size are produced: secondary oocyte and a polar body (degenerated).

Meiosis II occurs at fertilization, and at the end of this a mature ovum and another polar body form. The mature body is the only thing that grows.
Female sex hormones
1. Estrogens - Stimulate the development of female reproductive tract and contribut to the development of secondary sex characteristics and sex drive. (secreted by ovarian follicles and corpus luteum)

Progesterone - Stimulates the development and maintenance of the endometrial walls in prep for implantation (secreted by the corpus luteum during the luteal phase of menstration).
Different phases of menstrual cycle
1. follicular phase

2. ovulation

3. luteal phase

4. menstration
Follicular phase
1. Menstrual flow ends.

2. FSH (follicle stimulating hormone) promotes development of follicle.
Ovulation
1. A mature ovarian follicle bursts and an ovum is released.

2. Caused by LH (luteinizing hormone) that is preceded by a peak in estrogen levels.

3. During menopause, ovaries are less sensitize to FSH and LH (which stimulate follicle development).
Luteal phase
1. Progesterone causes glands of endometrium to mature and prepare for implantation of embyro.
Menstration
1. When ovum does not fertilize, the corpus luteum atrophies.

2. Drop in progesterone and estrogen, which gives rise to menstral flow. (menses).