Card Set Information
What is Genetics?
is the scientific study of heredity.
What is heredity
is the passing of offspring from parents
Define phenotype and genotype
Phenotype is the characteristics and genotype are the genetic makeup
: g: Tt, Tt
: tall or short
What is co-dominance
is when both alleles completely show through in the phenotype
What are incomplete dominance
is when one allele is not completely dominant over another
Ex: A cross between red (RR) and white (NN) four o'clock plants product pink-colored flowers (RN)
What are sex-linked traits
is when genes are located on a sex chromosomes (X, Y)
What does it mean if a trait has multiple alleles?
means that their genes have more than two alleles
What is the Law of Segregation
is when homozygous chromosomes separate during the formation of gametes
What is Law of Independent Assortment
states that genes are different traits that can segregate independently during the formation of gamates
What is a gene?
genes are segments of DNA that code for proteins and give an organism certain traits.
What is an allele
An allele is two or more forms of genes
is a homozygous organisms that always pass down a particular trait.
What is a Polygentic trait and list 3 traits in humans that are polygentic
is traits controlled by two or more genes.
ex: Skin color, height, and eye color
What is a pedigree and what is it used for?
Pedigree is an important tool for studying inherited diseases .
- they are used to figure out the genetic basis of a disease or trait from its inheritance pattern
-predict the risk of disease in future offspring in a family (genetic counseling)
Who was Gregor Mendel
was the father of genetics
During sexual reproduction, sperm and egg cells join in a process called__________
What new cell does fertilization produce
What did Mendel wanted to produce
he wanted to produce seeds by joining male and female reproductive cells from two different plants
producing seeds by joining a male and female reproductive cells from two different plants
what is a trait
a specific characteristics that varies from one individual to another
What are hybrids
the offspring of crosses between parents with different traits
What does the principle of dominance state
states that some alleles are dominant and others are recessive
When do alleles separate
during gamete formation
what is a punnett square
the gene combinations that might result from a genetic cross
If a disorder is dominant what will happen
one of the parents must have the disorder and does not skip a generation
What happens when a disorder is recessive
neither parents has to have the disorder because they can be heterozygous carriers. Usually skips a generation
-trait is rare in pedigree
-trait often skips generation and are hidden in heterozygous carriers
-trait affects males and females equally
-Trait is common in the pedigree
- Trait is found in every generation
- Affected individuals transmit the trait to approximately 1/2 of their children
-trait is common in pedigree
- affected fathers pass to all of their daughters
- an affected male will always have an affected mother
- trait is rare in pedigree
-trait skips generations
- affected father DO NOT pass to their sons
- Males are more often affected than females
- An affected female will always have an affected father
Are X-linked dominant diseases normal
no they are extremely unusual.
Often, they are lethal (before birth) in males and only seen in females
What happens in incomplete dominance
the heterozygous phenotype is a blend between the two homozygous phenotypes
Where can you see examples of codominance and multiple alleles
in the human ABO blood type
What is hemophilla
is also an X-linked recessive disorder. It is characterized by delayed clotting of the blood