1 / 44

Human Genetics

Human Genetics. Chapter 27 pp 565-583. Chromosome Number. Human sperm or egg cell has 23 chromosomes Human body cell has 23 pairs of chromosomes, or 46 chromosomes total Different organisms have different numbers of chromosomes. Amniocentesis. Way of looking at the chromosomes of a fetus

lumina
Download Presentation

Human Genetics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Human Genetics Chapter 27 pp 565-583

  2. Chromosome Number • Human sperm or egg cell has 23 chromosomes • Human body cell has 23 pairs of chromosomes, or 46 chromosomes total • Different organisms have different numbers of chromosomes

  3. Amniocentesis • Way of looking at the chromosomes of a fetus • Amniotic fluid is removed to extract fetal skin cells • Cells are grown for about 10 days to study chromosomes during cell division

  4. Sex Chromosomes • Human females have two X chromosomes in each body cell • Human males have one X and one Y chromosome in each body cell

  5. Autosomes • Chromosomes that do not determine the sex of the offspring • These are the same in males and females

  6. Human Characteristics • Two different forms of the same gene – one on each chromosome • Dominant – keep other genes from showing their traits • Recessive – do not show their trait when a dominant gene is present

  7. Punnett Square • Way to show which genes can combine when egg and sperm combine

  8. Incomplete Dominance • Neither gene is totally dominant over the other • New trait is expressed • Mixture of the dominant and recessive traits

  9. Codominance • Two genes are dominant over a third, but not dominant over each other

  10. Sex-linked Traits • Y chromosome does not have all of the gene located on the X chromosome • Genes on the X chromosome controls the traits

  11. Human Blood Types • Although three genes control blood type, a person only has two genes • A and B are dominant to O • They are not dominant to each other

  12. O AB A B OO AB AA or AO BB or BO Blood Types & Genes

  13. Type O blood

  14. Type A blood

  15. Type B blood

  16. Type AB blood

  17. Sickle-cell Anemia • Genetic disorder in which some red blood cells are shaped like sickles • Sickle cells do not carry oxygen as well as round blood cells

  18. Genotypes • RR = normal blood cells • RR’ = normal and sickle cells • R’R’ = sickle cell anemia

  19. Hemophilia • Rare recessive disorder in which a person’s blood does not clot • Small cuts may bleed for hours • Usually occurs in males

  20. Dyslexia • Dominant condition in which people see and write some letters or parts of words backwards • Also called word blindness

  21. The dyslexic may reverse letters like b and d, or p and q, either when reading or writing. • He may invert letters, reading or writing n as u, m as w, d as q, p as b, f as t. • He may mirror write letters and perhaps numbers, ‘ε’ for ‘3’. • He may read or write words like no for on, rat for tar, won for now, saw for was. • He may read or write 17 for 71.

  22. Color Blindness • Condition in which reds and greens look like shades of gray or other colors • Males are more likely to be color blind

  23. Genetic Counseling • The use of genetics to predict and explain traits in children

  24. Pedigree • Diagram that can show how a certain trait is passed along in a family

More Related