gen2 Flashcards
Mendelian pea plants
- easy to grow & breed
- self-fertilized
- easy to cross breed and propagate
Mendel’s postulate of inheritance
genetic characteristics are controlled by unit factors existing in pairs in individual organisms.
Mendel’s 2nd postulate of inheritance
when 2 unlike unit factors responsible for a single characteristic are present in an individual, 1 unit factor is said to be dominant to the other, which is said to be recessive.
Mendel’s 3rd postulate of inheritance
When gametes form, the paired unit factors separate, or segregate randomly so that each gamete receives 1 or the other with equal likelihood.
Genes
mendel’s unit factors, a unit of heredity that can be passed from parent to offspring and produce a given trait.
Alleles
Variations of a given gene
There are ___ alleles for every trait
2
A punnet square for an unknown phenotype
2 punnet squares
Dihybrid cross
looks at 2 traits at once
True breeding
They are homozygous for their trait
Mendel’s 4th postulate
During gamete formation, segregating pairs of genes, assort independently of each other
product law of possibility
the probability of 2 or more independent events occurring simultaneously is equal to the product of their individual probability.
Wild type
The most commonly produced phenotype in a population
Neutral/ silent mutation
protein/ DNA gets mutated but nothing happens
loss of function mutation
- gene product may be diminished
- confirmation of a certain protein may be completely changed so that it cannot function
- the gene product may not be produced at all
Gain of function mutation
gene is turned on all the time. Never turns off
threshold effect
A minimum of gene product is needed to meet a normal phenotypic expression
Incomplete dominance
Shows a mixture of genes and phenotypes
- neither trait is truly dominant
Tay- Sachs disease
No activity in hexosaminidase A, resulting in abnormal lipid storage that slowly destroys the brain and spinal cord cells.
Homozygous dominant
100% of enzyme produced, okay
Homozygous recessive
0% of enzyme produced, diseased
Heterozygous
50% of enzyme produced, okay
Factor 5 leiden
a liver enzyme responsible for the conversion of prothrombin into thrombin (needed for blood clotting)
Homozygous for factor 5
disproportionate risk of deep thrombolytic events and pulmonary clots