Chromosome Abnormalities : Chromosome Abnormalities Project in Biology
GLEN FREDRIE P. AGUILAR Slide 2: - can occur from structural defects in the chromosome or from having either more or fewer than the normal 46 chromosomes. Chromosome abnormalities Slide 3: Genetic Disease .
Here, chromosome 21 has three chromosomes instead of the usual two. This defect causes a genetic disorder known as Down syndrome. Certain genetic diseases are caused by abnormal chromosomes. Slide 4: A defective gene changes red blood cells into the shape of a crescent moon (bottom, left). This odd shape makes it difficult for the cells to pass through blood vessels to deliver oxygen throughout the body. Sickle-Cell Anemia Sickle-cell anemia is a genetic disorder. Sex chromosome aberrations occur in both males and females : Sex chromosome aberrations occur in both males and females Turner's syndrome : Turner's syndrome It arises because one of the two X chromosomes is absent in the female.
This results in a short, blocky physique and lack of sexual development. Klinefelter's syndrome : Klinefelter's syndrome In Klinefelter's syndrome the male usually has two X chromosomes and one Y chromosome, resulting in small genitals, lack of sperm formation, late puberty, and, occasionally, breast development. Slide 8: are caused by interaction of genes with such factors as drugs, radiation, vitamin deficiency, or viruses. Multifactorial Inheritance Disorders Some of the most common birth defects--including congenital heart disease, hip dislocation, cleft lip or palate, pyloric stenosis (obstruction of the lower opening of the stomach), and certain types of epilepsy--occur in this manner. Spina bifida, a neural tube defect that usually develops during the second month of gestation, results in defective closure of the spinal column. Counseling and Diagnosis : Counseling and Diagnosis Slide 10: Couples who are at risk for having a child with a genetic disorder can benefit from genetic counseling. The risk is considered high if genetic disorders have occurred in either the man's or the woman's family, if the couple are blood relatives, or if either of them belongs to a high-risk population. Slide 11: Some developmental disorders can be diagnosed with ultrasound in early pregnancy. Others can be detected by taking a sample of the amniotic fluid that surrounds the fetus in a procedure called amniocentesis or by taking a sample of the early, developing cells of the chorion, part of the placenta, in a procedure called chorionic villus sampling. Slide 12: Prenatal screening is recommended for pregnant women over 35, those who have already had a child with a genetic disorder, or those who have been exposed to radiation or certain drugs early in pregnancy. As more genes that cause specific diseases are being isolated, the use of screening tests to identify those people who unknowingly carry defective genes is becoming more widespread. (See also Disease, Human; Genetics.) Have you ever heard a news reporter talk about DNA? : Have you ever heard a news reporter talk about DNA? Reporters talk about DNA found at the scene of a crime. They talk about police finding DNA “fingerprints.” Police sometimes use DNA as a clue to find out who committed the crime. Slide 14: DNA is a substance that makes up genes.
Everything alive has genes.
Plants have genes.
Animals have genes.
You have genes. DNA WHAT IS DNA? Slide 15: All the features found in living things, such as eye color, the pattern on a butterfly’s wings, or the color of a flower’s petals, are determined by deoxyribonucleic acid (DNA).
DNA is a long, coiled molecule. It is located in structures called chromosomes, found within the nucleus of every cell. © Microsoft Corporation. All Rights Reserved.
Microsoft ® Encarta ® 2008. © 1993-2007 Microsoft Corporation. All rights reserved. DNA Genes : Genes Genes are the basic units of heredity.
Heredity means all the characteristics you inherit from your parents.
You get your genes from your parents.
You inherit half of your genes from your mother.
You inherit half of your genes from your father. Slide 17: A tree’s genes tell what shape its leaves will be.
A cat’s genes tell what color its fur will be.
Your genes tell what color your eyes will be.
Your genes tell what color your hair will be.
Everything about you comes from the code in your genes. Genes are a kind of code. WHERE ARE GENES? : WHERE ARE GENES? Different parts of you are made of different kinds of cells. Your muscles are made of muscle cells. Your skin is made of skin cells. The code in your genes tells your body to make different kinds of cells. The genes in each cell tell the cell how to work. They tell the cell when to make new copies of itself. Genes line up on strands called chromosomes in cells. Everything alive is made up of cells. Chromosomes are in the center, or nucleus, of cells. WHO DISCOVERED GENES? : WHO DISCOVERED GENES? An Austrian monk named Gregor Mendel first saw inherited patterns in pea plants. He experimented with pea plants in the 1860s.
One of the things, or traits, Mendel studied was what makes some pea plants tall and some short. He said that the traits must come from units of heredity passed from the parent plants. These units were later called genes. WHO DISCOVERED GENES? : WHO DISCOVERED GENES? In the mid-1900s, scientists discovered that genes are made of DNA. In the 1970s, scientists learned how to change DNA with genetic engineering. Scientists also learned that problems with certain genes cause diseases.
Muscular dystrophy, cystic fibrosis, and hemophilia are some genetic diseases—diseases caused by problems in genes. Today, scientists are looking for ways to cure genetic diseases by altering genes through a process called gene therapy. Slide 21: In the 1860s, Austrian monk Gregor Mendel discovered the basic laws of heredity by experimenting with pea plants. Gregor Mendel Microsoft ® Encarta ® 2008. © 1993-2007 Microsoft Corporation. All rights reserved. Thank you!!! : Thank you!!! Submitted to:
Miss Lotis Cruz