Genetics Flashcards
Science of heredity and variation
Genetics
Passing down of traits in the form of genes from parents to their children
Heredity
Difference in genes between individuals or groups of individuals
Variation
Specific characteristic that varies from one individual to another
Trait
Different possibilities for a given trait
Allele
Every trait has atleast how many alleles?
2
Sequence of DNA that codes for a protein and thus determines a trait
Genes
Father of genetics who identified specific traits in the garden pea
Gregor Mendel
Mendel’s conclusion
Law of dominance, Law of segregation, law of independent assortment
Hybrid offspring will only inherit the dominant trait in the phenotype
Law of dominance
Two alleles for each trait separate when gametes form
Law of segregation
Parents pass only one allele for each trait to each offspring
Law of segregation
When the two parent differ from one another by one trait only
Monohybrid cross
Alleles of different genes are inherited independently within the organisms that reproduce sexually
Law of independent assortment
Independent assortment takes place during the process of what?
Meiosis
The gene combination an organism has
Genotype
The way an organism looks
Phenotype
The genetic makeup of an organism
Genotype
The physical characteristics of an organism
Phenotype
Organism that has two identical alleles for a particular trait
Homozygous
Organism that has two different alleles for the same trait
Heterozygous
Result of the cross
First filial generation
Result of the cross
First filial generation
When one allele is not completely dominant over another
Incomplete dominance
When both alleles are expressed
Codominance
Humans have how many chromosomes and pairs?
46 chromosomes, 23 pairs
22 pairs are homologous which are called
Autosomes
1 pair is what?
Sex chromosomes
Sex chromosomes are homologous (XX)
Females
Sex chromosomes are different (XY)
Males
Genes for these traits are located only on the X chromosomes at the 23rd spot
Sex-linked traits
3 or more alleles of the same gene that code for a single trait
Multiple Alleles
Dominant blood
A and B
Recessive blood
O
Graphic representation of how a trait is passed from parents to offspring
Pedigreees
Linked genes sit close together on a chromosome, making them likely to be inherited together
Gene linkage
When one gene mutation results in two or more seemingly unrelated observable traits
Pleiotropy
Describes a certain relationship between genes, where an allele of one gene hides or masks the visible output or phenotype of another gene
Epistasis
A picture of an individual’s chromosome
Karyotype
A chromosome that is not directly involved in determining the sex of the individual
Autosome
A chromosome that is directly involved in determining the sex of the individual
Sex chromosome
Stable, heritable change in the genetic material
Mutation
Any change in the sequence of nitrogenous bases in the DNA
Mutation
One base is incorrectly added during replication and replaces the pair
Point mutation or single base pair
One or more extra nucleotides are inserted into replicating DNA
Frameshift mutation by insertion
One or more nucleotides is “skipped” during replication or otherwise exercised
Frameshift mutation by deletion
Associated with random changes that cause errors when DNA is produced in the cell
Spontaneous Mutations
the process in which the individuals are selected from a mixed population based on the phenotype
Mass selection
Crossing of two different but closely related strains
Hybridization
Opposite of hybridization; involves self-pollination of a single parent
Inbreeding
