Cc Flashcards
What is pleiotropy?
A gene impacting one or more characteristics of an organism
One gene can influence multiple traits.
What is the genetic basis of sickle cell disease?
A mutation from Glu to Val, changing RBC shape from round to sickle
This shape prevents hemoglobin from effectively carrying oxygen.
What is anemia?
A condition characterized by low iron and low oxygen transport
It can lead to heart failure and kidney damage.
What type of genetic disorder is sickle cell disease?
A recessive disorder
Both parents must be carriers for a child to inherit the trait.
Define monogenic traits.
Traits determined by one gene
Examples include certain single-gene disorders.
Define polygenic traits.
Traits determined by more than one gene
Examples include eye color, height, and skin color.
What are the two parts of a chromosome arm?
P (shorter) and Q (longer)
The P arm is shorter than the Q arm.
Who is Gregor Mendel and what did he study?
He used peas to discover traits
Mendel focused on flower color and pea shape/color.
What is the definition of a gene?
Information or code for RNA or proteins
Genes are located on chromosomes.
What is an allele?
A variant of a gene
There are two copies of alleles: recessive (r) and dominant (R).
What does homozygous mean?
Having two alleles of the same gene
Examples: RR (homozygous dominant) or rr (homozygous recessive).
What is a monohybrid cross?
A genetic cross between individuals differing in one trait
It helps illustrate inheritance patterns.
What distinguishes sex-linked traits from autosomal traits?
Sex-linked traits are located on sex chromosomes
Most are found on the X chromosome.
What is Hardy-Weinberg Equilibrium?
A state where allele and genotype frequencies remain constant in a population
This occurs unless evolutionary forces act on the population.
What is the Hardy-Weinberg equation for allele frequency?
P + q = 1
P is the frequency of the dominant allele, and q is the frequency of the recessive allele.
What does the Hardy-Weinberg genotype frequency equation represent?
2^p + 2pq + 2^q = 1
P^2 is homozygous dominant, 2pq is heterozygous, and q^2 is homozygous recessive.
Define incomplete dominance.
A genetic situation where neither allele is completely dominant
This results in a phenotype that is a blend of both alleles.
What is codominance?
A genetic situation where both alleles are fully expressed
Neither allele overshadows the other.
What is a mutation?
A change in the DNA sequence that can affect protein structure
Mutations can be neutral, beneficial, or harmful.
What is a silent mutation?
A mutation that does not affect the amino acid sequence
It may result from changes that lead to the same amino acid.
What is a missense mutation?
A mutation that causes a change in the amino acid sequence
Example: the mutation causing sickle cell disease.
What is a nonsense mutation?
A mutation that introduces an abrupt stop codon
This can lead to truncated proteins.
What does the term ‘locus’ refer to?
The location of a gene on a chromosome
It helps in identifying where specific traits are determined.
