Mutations/genetic Disorders Flashcards
(36 cards)
What are the 2 types of mutations
Gene mutations and chromosomal mutations
What are mutations
Changes in the genetic sequence that can be good, bad, or have no effect at all
What is a gene mutation
Produce changes in a single nucleotide
What is a point mutation
Results in changes in one or a few nucleotides
What is a substitution
It usually affects a single amino acid
What is a deletion or insertion
It usually effects all the amino acids after the mutation
What is another name for deletions or insertions
Frames shift mutations
What is a chromosomal mutation
It involves the change in the number or structure of chromosomes
Deletion
A piece of the chromosome is lost
Duplication
Extra parts of a chromosome
Inversion
A piece of a chromosome breaks off and reattaches backwards
Translocation
A piece of the chromosome breaks off and attaches to another chromosome
Nondisjunction
Occurs in meiosis 1 when homologous chromosomes fail to separate. This results in abnormal number of chromosomes. EFFECTS OFFSPRING
Polyploidy
Condition that occurs when an organism has extra sets of chromosomes.
Triploid/tetraploid plants are stronger than diploid
Dominant human traits
Require only 1 type of the allele to be expressed
Widows peak, hitchhikers thumb, cleft chin
Dominant doesn’t mean it is the most common
Dominant autosomal genetic disorders
Achondroplasia, huntingtons disease,hypercholesterolemia
Achondroplasia
- Males and females equally likely to inherit
- From of dwarfism that effects the growth of long bones
- Dd-dwarf DD-dwarf dd-normal height
- Most cases are spontaneous mutations
Huntingtons disease
- results in progressive loss of muscle control and mental function until death occurs
- symptoms do not appear until age 30-50
- death occurs 10-15 years after symptoms occur
Hypercholesterolemia
-condition characterized by higher levels of cholesterol in the blood which can lead to heart disease/clogged arteries
Recessive genetic disorders
Require 2 copies to be expressed
Can be carrier and not expressed
PKU
- lack the enzyme required to break down phenylalanine, an amino acid found in milk and other things
- this amino acid will accumulate in the brain and lead to mental retardation
- today infants are tested and if positive, they are fed a special diet until the central nervous system is fully developed
- mothers with PKU must eat a diet while pregnant
Tay Sachs
- more prominent in Jewish people of central and Eastern European ancestry
- individuals lack the ability to break down gangliosides (lipid) in nervous system
- leads to breakdown of the nervous system
- symptoms appear 3-6months of age
- regression of motor skills, deafness, blindness, seizures
- death usually occurs before age 5
Albinism
- caused by a mutation of 1 of several genes that provide the info for melanin production
- results in little to no color(pigment) in the skin, hair, and eyes
Food chain
Series of steps that show the transfer of energy from 1 organism to the next