week 1- transmission genetics Flashcards
what did mendel’s legacy help with
Darwins theories
what is the blending hypothesis
the idea that genetic material from the two parents blends together
what is the particulate hypothesis
the idea that parents pass on discrete heritable units
how did Mendel discover the basic principles of hereditary
by breeding garden peas in experinments
what is a character
a heritable feature that varies among individuals
what is a trait
each variant for a character
how many unit factors are most human traits controlled by
more than one
how did Mendel begin his experiments
- bred pure breeds
- ## studied one trait at a time
what did Mendel matte in a typical experiment
two contrasting, true breeding varieties (hybridisation)
what are the original true breeding parents in genetic crossed called
F1 or parental generation
what is the parental generation/F1 hybrid offspring called
F1 generation or first fillial generation
when are F2 generations produced
when F1 individuals self-pollinate or cross-pollinate with other F1 hybrids
what. does further interbreeding form
F3 and so om
what are models postulates
- heritable traits are determined by heritable factors / genes. genes come in pairs
- genes come in different versions called alleles.
where does each gene reside
at a specific locus on a specific chromosome
what is the law of segregation
During gamete production, each egg or sperm cell receives just one of the two gene copies present in the organism, and the copy allocated to each gamete is random
what is the law of independent assortment
Genes for different traits are inherited independently of one another
what is phenotype
physical expression of a trait
what are genes
unit factors
what are alleles
alternative forms of a single gene
what is genotype
genetic makeup an individual
what is homozygous
two same alleles
what is heterozygous
two different alleles
which alleles are not true-breeding
heterozygotes
How did Mendel develop the law of independent assortment
using a dihybrid cross
what does the law off independent assortment state
It states that each pair of alleles segregates independently of any other pair of alleles during gamete formation
what does crossing two true-breeding parents differing in two characters produce
hihybrids in the f1 generation, heterozygous for both characters
how can it be determined whether two characters are transmitted to offspring as a package or individually
using a dihybrid cross, a cross between F1 dihybrids
what is epistasis
where the allele of one gene can mask the effects of the alleles of another gene
(Depends upon the allelic combination of two independently assorting genes)
what is incomplete dominance
when the phenotype of the dominant allele doesn’t completely mask that of the recessive allele
(Crosses between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits.)
what is codominance
phenotypes of both alleles are expressed
(Crosses between organisms with two different phenotypes produces offspring with a third phenotype in which both of the parental traits appear together)
