Lab 7 - 13

• Cell theory is the idea that all living things are made of cells, and all cells come from preexisting cells.
• Cell division is the cell’s ability to generate more cells.
• Mitosis is the basic form of cell division that occurs for growth, damage repair, or asexual reproduction.
• Meiosis is the cell division to produce sex cells for sexual reproduction.
• Life history is what happens during an organism’s life. A cell’s life history is the cell cycle.
• The phases of the cell cycle include interphase, mitosis, and cytokinesis.
• There are three phrases of interphase: G1, S, and G2.
• List the phases of mitosis (5 terms).

  prophase, prometaphase, metaphase, anaphase, telophase
• During prophase (mitosis), chromosomes condense, the nuclear membrane disassembles, and mitotic spindles begin to form.
• During prometaphase (mitosis), the spindle fibers attach to the centromeres of each chromosome.
• During metaphase (mitosis), spindle fibers line the chromosomes up along the metaphase plate.
• During anaphase (mitosis), spindle fibers pull the sister chromatids apart.
• During telophase (mitosis), the spindle fibers disassemble, identical chromosomes reach opposite sides of the cell, and the nuclear membrane reforms.
• Cytokinesis is when the cell membrane pinches to create 2 daughter cells during cell division.
• Animal cells show a cleavage furrow, and plant cells use a cell plate during telophase.
• What are the two mechanisms that cells use (animal, plant) to split during telophase and cytokinesis?

  cleavage furrow, cell plate
• Gametogenesis is the production of sex cells. It only occurs in reproductive organs.
• A gamete is a sex cell, while somatic cells are those not involved in gametogenesis.
• Sister chromatids are identical chromosomes joined by a centromere. Homologous chromosomes are those which contain similar, but not identical genetic information.
• During prophase I, the homologous chromosomes undergo synapsis to form a tetrad
• Recombination is the crossing over of alleles between homologous chromosomes, which create a recombinant chromosome.
• During metaphase I, spindle fibers attach to the tetrads, which line up at the metaphase plate.
• Independent assortment is the random alignment of tetrads along the metaphase plate.
• What are the two sources of genetic diversity that occurs during meiosis?

  recombination, independent assortment
• At the end of meiosis I, each daughter cell has one homologous chromosome, or two sister chromatids.
• Reduction division is cell division that results in daughter cells with half the number of chromosomes.
• In meiosis II, the same process as meiosis I occurs, but instead, the sister chromatids are pulled apart.
• Ploidy is the total number of sets of chromosomes in the somatic cells of organisms.
• Haploid cells only have one copy of each chromosome. Diploid cells have a pair of chromosomes.
• Fertilization is the fusion of a female and male gamete. A zygote is produced.
• The embryo is the first stage of development that occurs after a zygote undergoes cell division.
• Spermatogenesis is the production of sperm in males. It occurs in the seminiferous tubules.
• Hormone production occurs between the seminiferous tubules, in the interstitial space.
• Primary spermatocytes haven’t undergone meiosis yet, while secondary spermatocytes have completed meiosis.
• Oogenesis is the production of ova in females. There are four stages, where the primary oocyte matures into the secondary oocyte.
• The ___ ___ matures into the ___ ___ during oogenesis.

  primary oocyte, secondary oocyte
• The follicle is composed of the oocyte, the egg, and granulosa OR follicular cells.
• What are the two components of the follicle?

  oocyte, granulosa follicular cells
• The primary follicle is surrounded by 2 layers of granulosa cells.
• The secondary follicle has pockets of fluid between the granulosa cells and the primary oocyte.