In older women or women determined to be at high risk for conceiving babies with genetic abnormalities, procedures called Amniocentesis and Chorionic Villi Sampling can be conducted to get the karyotype of the developing fetus. Thus chromosomal abnormalities can be determined early in development.ġ6 Down’s Syndrome Extra or absent autosomes often lead to spontaneous abortion of the fetus. This procedure can be seen below:ġ4 Amniocentesis & Chorionic Villi Sampling The resulting karyotype should show 22 pair of autosomes and 2 sex chromosomes (X or Y). After photographing the metaphase chromosomes, the individual chromosome images are cut out and matched up by homologous pairs. This is a photographic record of an individual’s chromosomes. Genetic Errorsġ2 Karyotype A karyotype can identify chromosomal aberrations. Chromosomal aberrations may be fatal to a developing embryo or may lead to profound physical or mental problems. But this can also present major problems. This can be a simple source of genetic variety. Sometimes a chromosomal separation during meiosis doesn’t go right and errors result . The fourth source of genetic variation is mutation. ![]() Three of these occur during meiosis and are as follows: 1) the independent assortment of chromosomes during metaphase I 2) the presence of different information on the two chromosomes of a homologous pair 3) crossing over to create new gene combinations. The process that creates diploid cells is called mitosis A comparison of mitosis and meiosis can be seen in the next slide.ġ0 Genetic Variation There are four main sources of variability in sexually reproducing organisms. Meiosis The process that creates haploid cells is called meiosis. All cell divisions after fertilization are mitotic divisions The process that creates haploid cells is called meiosis.Ħ Mitosis vs. The union of sperm and egg then creates a new fertilized egg cell (zygote) that has the diploid number of chromosomes. Why does this occur? Because otherwise the number of chromosomes would double in the cells of each new generation of individuals! Sperm and eggs are gamete cells, which are haploid.ĥ Meiosis Mature sperm and eggs are haploid cells (1N) that have half the normal number of chromosomes. This is the N#, otherwise referred to as Haploid. Before fertilization can take place, the number of chromosomes must be reduced to half their normal number. All of our somatic cells are diploid.Ĥ Sperm & Eggs The only exception to this occurs during the production of gametes (sperm or eggs). In human cells that have 46 chromosomes, N = 23. A diploid cell has a 2N number of chromosomes, where N equals the number of chromosomes in the cells of that species. Any cell that has two sets of chromosomes is said to be a diploid cell. In sexually reproducing organisms, one of these sets was inherited from each of the parents. You will not post it on public websites or share with your coworkers or peers.In eukaryotes, such as us, a cell has two sets of chromosomes. By purchasing this product, you agree not to share this item and use it for personal use only. By purchasing this product you acknowledge that you have read and understood the Terms of Use. Disregarding the copyright is a violation of the Digital Millennium Copyright Act and subject to legal action. It is a violation for individuals, schools, and districts to redistribute, edit, sell, or post this item on the Internet or to other individuals. Purchase of the product is for single classroom use by the purchaser only. ☆ Click on the Preview for a High-Resolution Look at this Handout! The digital version is in Google Slides with clickable video link and pre-formatted text boxes that your students can type directly into. ⭐ Save $$$ by purchasing this resource and other Amoeba Sisters video handouts in this Growing Bundle! Click HERE to view! ⭐ The Video Includes the Following Topics ⭐ A Mix of Crossword Puzzles, Matching, Labeling Diagrams, True or False Questions and/or Graphic Organizers ![]() Multiple Choice Questions in order of the video They include 2 pages of questions that are differentiated for beginning biology students.Īll video handouts in this series include: ![]() ![]() These handouts, made by Science Is Real, are designated for standard and lower-level biology students. This handout was not made by the Amoeba Sisters. Meiosis video made by The Amoeba Sisters and hosted on YouTube. ⭐ ⭐ ⭐ ⭐ PDF, Google Slides, and Answer Key Included! This video handout is for the Mitosis vs.
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