Genetic Basics
The study of genetics began with observations by...?
Gregor Mendel
AA is an example of what kind of genotype?
Homozygous dominant
What are the 3 types of non-Mendelian traits?
Incomplete Dominance, Codominance, Epistasis
What's a pedigree chart?
A record of the family of an individual; used to study the transmission of a hereditary condition
Unaffected parents are called ________.
Carriers
Each trait is determined by a pair of discrete units called...?
Alleles
What's the difference between a dominant and recessive trait?
Dominant - trait refers to a genetic feature that "hides" the recessive trait in the phenotype of an individual
Recessive - a trait that is covered over by another form of that trait and seems to disappear
What's an example of incomplete dominance?
When red snapdragons are crossed with white snapdragons, they produce pink snapdragons.
Generations are identified by ______ _________, while individuals are identified by ______ ________.
Roman numerals; Arabic numerals
Some alleles are dominant and some are recessive. (Dominance/Segregation/Independent Assortment)
Principle of Dominance
The genes of an organism is the _________, while the physical expression of the gene is the _________.
In pea plants, violet flowers are dominant over white flowers. Cross a heterozygous violet flower with a homozygous recessive white flower.
V v
v | Vv vv
v | Vv vv
Define codominance.
Both phenotypes are shown.
If two affected individuals give rise to an unaffected child the affected condition is...?
Dominant
What is one example of a career option that uses pedigree charts?
Genetic counselor
State the difference between homozygous and heterozygous.
Homozygous - an organism carrying two copies of the same allele of a gene
Heterozygous - an organism carrying two different alleles of a gene
In humans, brown eyes are dominant over blue eyes. If homozygous dominant brown eyes and heterozygous brown eyes were crossed, what percentage of the offspring are going to have blue eyes?
0%
What's an example of epistasis?
White llamas/Albinism
If two unaffected individuals give rise to an affected child, the allele for the affected condition is...?
Recessive
Genes for different traits can segregate independently during the formation of gametes. (Dominance/Segregation/Independent Assortment)
Principle of Independent Assortment
What are the three laws founded by Mendel?
Law of Dominance, Law of Segregation, Law of Independent Assortment
Also in humans, no freckles are dominant over freckles. Cross homozygous brown eyes and freckles with homozygous blue eyes and heterozygous freckles. What percentage of offspring are going to have brown eyes with freckles?
50%
If bear with black fur (BB) and a bear with white fur (WW) were crossed, what color would the offspring's fur be, according to codominance?
The offspring would be black & white. (BW)
If two unaffected parents had an unaffected offspring, are they homozygous dominant, heterozygous, or homozygous recessive?
⬤─⬛
❘
◯ ⬛
Heterozygous
Brown eyes are a dominant eye-color allele and blue eyes are recessive. A brown-eyed woman whose father had blue eyes and whose mother had brown eyes marries a brown-eyed man whose parents are also brown-eyed. They have a son who is blue-eyed. Draw a pedigree chart showing all 4 grandparents, the 2 parents, and the son.
Top Row: Affected male married to unaffected female, unaffected male married to unaffected female
Middle Row: Unaffected female married to an unaffected male
Bottom Row: Affected male