Mutations/genetic Disorders Flashcards
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
Food web
Complex interactions of energy exchange within a ecosystem
Ecological pyramid
Energy pyramid shows movement of energy from 1 tropic level to the next
Shows how the amount of energy decreases
How much energy is transferred from one tropic level and why
Only 10 percent because some energy is lost as heat
Biomass pyramid
Shows the amount of living tissue decreases as you move up the pyramid
Pyramid of numbers, why
Shows that the number of individuals decreases as you move up the pyramid
Not enough energy available
Galactosemia
- condition in which the body can’t metabolize galactose
- if an infant is given milk galactose it will build up in the infants system
- it leads to damage in the brain, kidneys, liver, and the eyes
- must avoid galactose for life
Cystic fibrosis
- more common in people who originated in northern Europe
- results in the production of excessive mucus
- this interferes with breathing and digestive processes
Sickle cell anemia
- affects one out of 500 African-Americans
- results from a single point substitution which results in glutamic acid instead of valine in the recipe for hemoglobin
- The hemoglobin is not as soluble and often sticks together in long strands
- this results in the red blood cell being sickle shaped
- these new cells can block bloodflow due to rigidness
- results in physical pain and weakness and damage to the brain, heart, and spleen.
- and be fatal
Why are African-Americans more likely to get sickle cell
- it is more common because heterozygous individuals are resistant to malaria
- heterozygous individuals produce normal and abnormal cells
- The abnormal cells destroy malaria
Multiple allele traits
Blood type
Blood type
- A B and O
- results from the presence of certain proteins on the red blood cell called antigens
Explain each blood type
- blood type a has anti-b antibodies and antigen A
- B has anti-a anti-bodies and antigen b
- A B has no anti-bodies but if to much of one type of an antigen, it will attack the other
- o has anti-b anti-a antibodies and no antigens
