Biology Test: Basic genetics Flashcards
The study of heredity
Genetics
The passing of traits from parents to offspring
Heredity
Austrian Monk who studied heredity
Gregor Mendel
Why did Gregor Mendel use pea plants for experiments? (4)
-Short life cycle
-Easily observable traits
-Small size
-Easy to care for
What was Mendel’s experimental design? (3)
-He looked at one variable at a time (by using true breeding)
-“controlled” the experiment (pollination by hand)
-Large sample size (100s of plants for each trait)
Pollen from one plant lands on the pistol of a flower on a different plant
Cross pollination
Pollen from one plant lands on the pistol of a flower on the same plant
Self pollination
Gregor Mendel’s conclusions:
- 2 genetic factors control each inherited trait
-One parent contributes each factor
-Traits could be dominant or recessive
The factors that determine a trait must seperate or segregate, into the reproductive cells of the plants
Principle of Segregation
When an organism has the same alleles of a gene (ex: AA or aa)
Homozygous
When an organism has different alleles for a gene (ex: Aa)
Heterozygous
Used to make predictions about the possible genotypes and phenotypes of offspring
Punnett Square
Mating an organism with an unknown genotype with a known recessive genotype to see what happens
Test Crosses
A way to look at phenotype of offspring to determine the genotype of parents
Test Crosses
They show the presence or absence of a trait in a # of generations
Pedigree
How do you read pedigrees?
You look at phenotypes to determine a possible genotype
Not simply recessive or dominant traits (a blend of traits)
Incomplete dominance
Incomplete dominance example
Flower color in snapdragons
Both alleles are dominant, two traits fully expressed
Co-dominance
Co-dominance example
Type AB blood
Sex-linked traits are…
controlled by the sex chromosomes (X and Y)
Sex-linked trait example
Red-green color blindness
The process in which genetic information is activated to make a genetic product
Gene expression
What influences gene expression?
-DNA molecules
-Enviornment
Cause the transcription factors to “fall off”
Terminator sequences
DNA sequences that bind to promoters in front of genes and act as switches telling RNA polymerase whether the gene needs to be turned on or silenced
Enhancers and silencers
Expression of different genes depends on the presence of different ________________
hormones
External stimuli
light and temperature
both influence gene expression
Drugs or pollutants that can alter gene expression in babies that are developing
Chemicals
The physical expression of a gene
Phenotype
The genes that have been inherited for a gene
Genotype
F1 generation (Cc)
Heterozygous
Genes on X and Y chromosomes
Multiple gene interactions
More than 2 types of a gene
Multiple alleles
Autosomes and Sex chromosomes use _____________ chromosome(s)
All
What 2 types of inheritance are exemplified in blood types?
- Co-dominance (AB)
- Inheritance by multiple alleles (EA, EA, e)
Sequences of DNA that come before a gene that tell the RNA polymerase where to bind to begin copying the gene into a strand of mRNA
Promoters
The process that converts undifferentiated cells to many different types of specialized cells in our body
Cell differentiation
A general term that includes the addition or removal of methyl groups from the DNA of a gene and the addition or removal of acetyl groups from histones
Epigenetic change
What does Epi mean in epigenetic?
over/above
