Genetics (exam 1) Flashcards
What sugar makes up DNA?
Deoxyribose
What are the codons in DNA and how do they pair?
A-T
G-C
What are the codons in RNA and how do they pair?
A-U
G-C
Transcription
DNA to mRNA
In nucleus
Translation
mRNA to protein
In ribosome
Gene splicing
Introns spliced out
Exons kept
Polymorphisms
Mutation
Changing of genes
Normal changes in alleles
Least pathologic
Point Mutation
Change 1 base
Base Pair Substitution
Type of point mutation
1 pair replaces another
Frameshift Mutation
Insertion or Deletion
Most pathologic
Insertion
Insert 1 or more pairs
Not in group of 3
Change reading frame
Deletion
Delete 1 or more pairs
Not in group of 3
Change reading frame
Inversion
Section of DNA is reversed
How many chromosomes are there?
46 total
23 pairs
How many autosomes are there?
22 pairs
44 total
Mutagens
Agents that increase the frequency of mutations
Euploid Cells
Correct number of chromosomes
Polyploidy
More than normal copies
Ex: Triploidy (3 copies, 69 chromosomes)
Ex: Tertraploidy (2 copies, 92 chromosomes)
Euploidy
Correct # of chromosome
2 pairs, 46 chromosomes
Aneuploidy
Wrong # of chromosomes
Does not contain 23 chromosomes
Not a set of chromosomes wrong
Trisomic/ Trisomy
3 copies of one chromosome
Monosomy
Presence of only one copy of a chromosome
LETHAL of any chromosome, unless a male sex chromosome
Nondisjunction
An error where homologous chromosomes fail to separate during meiosis
Partial Trisomy
An extra portion of a chromosome is present in each cell
Chromosomal Mosaics
Body has 2 or more different cell lines
Trisomy 13
Patau Syndrome
Most pathologic
Trisomy 18
Edwards Syndrome Pretty Pathologic (50% die w/ in 1st week, rest w/ in 1st year)
Trisomy 21
Down syndrome
Risk increases with mothers age
Most common
Least pathologic
Trisomy X
XXX
Most common aneuplodies
47 chromosomes
Monosomy X
XO
45 chromosomes
Klinefelter Syndrome
XXY
47 chromosomes
Mode of Inheritance
Pattern in which a genetic disease is inherited through generations
Autosomal Recessive
Occur on the 22 pairs of autosomes
Need 2 recessive copies
Autosomal Dominant
Occur on the 22 pairs of autosomes
Need 1 dominant
X-Linked Recessive
Occur on X
Male expresses it if it is present
Female needs 2 copies of it to present
X-Linked Dominant
Occur on X
Need 1 to present
Genotype
Set of genes an individual has in its genome
Phenotype
Physical or attributes coded by genes and environmental factors
Polygenic Traits
Several genes acting together for trait
Multifactorial Inheritance
Environmental factors influence expression of trait
