General Terms Flashcards
mRNA
- Created during transcription
- Carries small parts of DNA to other parts of the cell for processing
Transcription
when DNA information transcribed to make an mRNA
Translation
When the information from an mRNA is translated into a protein
-ultimately determines phenotype
Chromosomes
Coiled DNA and the means by which the genes are transmitted from generation to generation
How many chromosomes and pairs do humans have?
46 chromosomes
23 pairs
Autosomes
Not sex chromosomes
22 pairs
Where are autosomes kept?
Nucleus
What does mitochondrial DNA encode?
- some proteins for oxidative metabolism
- tRNA
tRNA
used in translation of proteins
Locus
the exact location of a gene on a chromosome
Alleles
- Homologous copies of a gene
- so one of the same gene from mother and father
Homologous pair
- Same chromosome, but one from mom and dad
- Carry the same genes in the same order, but the alleles for each trait might not be the same
Homozygous
pair of matching alleles (EE or ee)
Heterozygous
one allele is dominant and one is recessive (Ee)
The Law of Uniformity
AA + aa = Aa
Law of Segregation
Each gamete contains only one of two copies of a gene
Law of Independent Assortment
Members of different gene pairs assort independently of one another
Alkaptonuria (AKU)
rare disease that causes severe, early-onset osteoarthritis
Mutation
A change in DNA that may adversely affect the host
Germinal Mutation
- Caused by radiation or chemicals
- may affect a single gene or an entire chromosome
- affects progeny of the subject
Somatic Mutation
Mutation in a somatic (non sex) cell
Chromosomal Aberrations
- Can be morphological or lethal
- Alteration in the number or physical structure of chromosomes
Spontaneous Miscarriages
- 40-50% of all 1st trimester losses
- not enough genetic material to carry on
Translocation
Where two non-homologous chromosomes have switched terminal segments
Inversion
Where the order of genes of a section of the chromosome is reversed
Non-disjunction
Failure of chromosomes to separate and results in loss or gain of a chromosome
Aneuploidy
Where extra or fewer copies of certain genes or chromosomal regions are present
Monosomy
- Type of aneuploidy
- one member of a pair of chromosomes is missing
Trisomy
- Type of aneuploidy
- One extra chromosome is present
Polysomy
- Type of aneuploidy
- more than 3 copies of a chromosome are present
Polygenic
- Combined action of alleles of one or more gene
- where most human diseases come from
Monogenic
Diseases or conditions that result from the action of alleles in one gene
Mendelian Phenotypes
Single gene alterations
Autosomal Dominant
Only one parent has to be affected for offspring to be affected
