Mitosis Meiosis

by Tehescmarts
Last updated 7 months ago

Discipline:
Science
Subject:
Biology

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Mitosis Meiosis

Mitosis & Meiosis

Mitosis & Meiosis

Review for Exam

Reproduction

Mitosis & Meiosis

Cell Growth--Before a cell divides it must replicate its DNA. After sister chromatids are pulled apart, cytokinesis begins. This is asexual reproduction and makes a cell with the exact same DNA as the parent cell. In sexual reproduction, gametes (containing half of the chromosomes) combine--egg and sperm. Gametes are the result of meiosis, in which cells divide twice. In the first division of meiosis chromosomes replicate and two cells are formed just as in mitosis. In the 2nd part of meiosis, the two cells are split in half with each cell receiving only half of the DNA/chromosomes. When the two gametes merge, this is called fertilization and the new cell is called an embryo. Seeds and eggs contain embryos. As these grow they must differentiate so that they form a certain type of cell, such as a muscle cell or a nerve cell.

The Cell Cycle--featuring mitosis. An overview with graphics and explanation.

The Cell Cyle

Mitosis begins as the long threads of DNA begin to coil. They form the strands we call chromosomes. Protein fibers grow from the organelles called centrioles forming a latticework of spindles. The nuclear membrane disintegrates. A spindle from each centriole attaches to each one of the chromosomes. The chromosomes move to the center and are then each chromotid is pulled to opposite poles. Other spindles are pushing against each other stretching the cell. The chromatids unwind and the nuclear membranes form. The nuclei and cytoplasm separate and form the beginnings of the new cells.

Stages of Mitosis--InterphaseProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesis

Meiosis starts out like mitosis, but each homologous chromosome finds its counterpart. These have equivilent information--one set from father and one set from mother. Next the two homologues trade genes in a process called crossing over. This forms new chromosomes. Maternal and paternal chromosomes are placed randomly on each side of the midline. This can also lead to genetic variation. Spindle fibers pull the homologues apart. The sister chromatids are pulled apart and contain twice the genetic material the cells will need. Next these cells must be divided in two. This 2nd division produces 4 sets of unique chromosomes. They carry half the genetic information and are called haploid cells. Many will mature into eggs and sperm which are reproductive cells called gametes.

Regeneration of planaria after being sliced into pieces. (Not sure what the Japanese is.)

Great student made video. Mentions tetrads.

I see trees of green Red roses too, They reproduce in a way different than you. and I think to myself, What a wonderful world. Haploid spores grow, into gametophytes, Gametophytes make gametes to fertilize and I think... sperm and egg make a zyogote when they fertilize. A zygote grows into a 2n sporophyte I see sporophytes grow, I give them co2 They photosynthesize for me and you. Through meiosis sporophytes, make spores then we continue the cycle once more. And I think to myself....

Black and white footage of normal and cancer cells. This segment depicts cell growth, with the first segment displaying normal cells, the second segment (1:20) displaying cancer cells and the third segment (2:38) showing both normal and cancer cells. Differences in ruffling (changes in the cell membrane) and movement are emphasized.This video has no audio.

Animation of human fertilization

Animation to show how a baby develops during pregnancy.

Pregnancy, labor, and birth.

Differentiation==stem cells enable the growth of specific cells.

The relationship between surface area and volume.

How Cancer Develops

Mitosis Dance


Comments

  • Tehescmarts 7 years ago

    Tehescmarts's avatar

    Added Mitosis Dance. Do you have any helpful links or ideas for learning mitosis or meiosis.

  • Tehescmarts 7 years ago

    Tehescmarts's avatar

    Thank you Isaiah78.