Download presentation
Presentation is loading. Please wait.
Published byAmanda Barnett Modified over 9 years ago
3
Studying humans requires alternative methods. Human geneticists use. Human are 4.3.12 – Deduce the genotypes and phenotypes of individuals in pedigree charts.
4
Label:
5
4.3.12 – Deduce the genotypes and phenotypes of individuals in pedigree charts.
6
Human Pedigree tracing a dominant trait
7
Human Pedigree tracing a recessive trait
8
Human Pedigree tracing a sex-linked trait
9
Human genetic disorders result from. 1.Gene Mutations – Hundreds of human genetic disorders involve defects caused by mutations of Disorders caused by mutated alleles: PKU, cystic fibrosis, sickle cell anemia, Tay-Sachs disease 4.1.3 – Define gene mutation. 4.1.4 – Explain the consequence of a base substitution mutation in relation the process of transcription and translation, using the example of sickle-cell anemia.
10
Sickle Cell Anemia is the result of a gene mutation called a Hemoglobin is found in your. Each hemoglobin molecule is made up of ( -hemoglobin) and ( -hemoglobin) The mutation producing sickle cell hemoglobin is in the gene for -hemoglobin. 4.1.4 – Explain the consequence of a base substitution mutation in relation the process of transcription and translation, using the example of sickle-cell anemia.
13
2.Chromosome mutations – Results from nondisjunction – 4.2.4 – Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21).
14
Extra chromosomesMissing chromosomes
15
Fertilization may result in trisomy or monosomy Trisomy – ○ Example: Down’s Syndrome (Trisomy 21); Klinefelter’s Syndrome (XXY) 4.2.4 – Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21).
16
○ Trisomy 21 - Down Syndrome 3 copies of chromosome 21 Mild to severe mental retardation Many lead productive lives
17
○ Klinefelter Syndrom (XXY condition) Most from non-disjunction in mother Tall, some mental slowness Poor male sex organ development; breast development; usually sterile Personal story
18
Monosomy – ○ Example: Turner Syndrome (XO) 4.2.4 – Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21).
19
○ Turner Syndrome one too few chromosomes (XO) Sterile (cannot have children), shorter than average, heart defects, premature aging, shorter lives ○ YO = LETHAL No babies have been reported being born without an X
20
Nondisjunction of sex chromosomes
21
Some genetic disorders are caused by Examples include: Hemophilia, Color blindness, and Duchenne muscular dystrophy
22
Karyotype - refers to both the chromosome composition of an individual and to a photomicrograph showing the chromosomes Uses: ○ To detect genetic disorders ○ For genetic counseling of prospective parents 4.2.5 – State that, in karyotyping chromosomes are arranged in pairs according to their size and structure.
23
Process: ○ Fetal cells, cells from bone marrow, skin, or blood are cultured and then treated with colchicine (arrests the cell in metaphase) ○ Chromosomes are 4.2.5 – State that, in karyotyping chromosomes are arranged in pairs according to their size and structure.
25
Many birth defects and genetic abnormalities can be detected before birth. 4.2.6 – State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.