Mendelian Genetics (chapter 17) Flashcards
monohybrid cross?
a mating of two true breeding individuals tracking a SINGLE character/trait
what are true breeding parents referred to as?
P generation (for parental)
the hybrid offspring of true breeding parents is referred to as?
F1 (first filial)
mating the F1 generation produced the _____ generation
F2 (second filial)
what happens to the F1 generation during a monohybrid cross?
all offspring will resemble the dominant trait
what happens to the F2 generation during a monohybrid cross?
the recessive trait will reappear
what is the ratio for the F2 generation in a monohybrid cross?
3:1
what is the difference between mono and dihybrid crosses?
in a monohybrid cross, mendel followed and studied one trait, while in a dihybrid cross, he followed two
what is a dihybrid cross?
the mating of two heterozygous individuals for two traits
what is the ratio for a dihybrid cross?
9:3:3:1
how can you solve a dihybrid cross?
a punnett square
incomplete dominance? (ex: red and white flower phenotypes produce pink)
the lack of a dominant gene, where an offspring is able to show an appearance in between the phenotype of the two parents
phenotype?
the appearance of an organism (ex: white coloured flowers)
what is a genotype?
the genetic makeup of an organism
what are heterozygous vs. homozygous alleles?
heterozygous: Aa or aA
homozygous: AA or aa
codominance (ex: red hair on a cattle (HrHr) is codominant to white (HwHw))
when both alleles are found in the phenotype of the offspring
multiple alleles
multiple alleles is when the followed traits have more then two allelic forms (ex: blood types A, B and O)
test cross?
an experiment to determine the genotype of an individual with a dominant phenotype
what two genotypes can an individual with a dominant phenotype have? (test cross)
homozygous dominant (AA) or heterozygous (Aa)
what do you cross the individual with to perform a test cross?
homozygous recessive individual (aa)
if the offspring all show the dominant trait, what is the genotype of the tested individual? (test cross)
homozygous dominant (AA)
if some offspring show the recessive trait, what is the genotype of the tested individual? (test cross)
heterozygous (Aa)
what is the expected ratio of dominant to recessive offspring if the tested individual is heterozygous (Aa)? (test cross)
1:1 half dominant half recessive
genetics is the study of ___________ of _________ from parents to offspring
transmission of characteristics
heredity is the passing of ______ from parents to offspring
traits
what did aristotle believe?
that traits were passed through the bloodline
what did gregor mendel preform experiments on?
garden peas
allele
alternate forms of a gene controlling a given characteristic
homozygous
having a pair of identical alleles (ex: TT or tt)
heterozygous
having two different alleles for a character/trait (Tt or tT)
cross
the mating of two organisms
are true breeding parents (P generation) always homozygous or heterozygous to start?
homozygous (AA or aa)
if you had a punnet square and the results gave RR, Rr, Rr, rr, what would the genotypes be? and what would the phenotype summary be?
25% homologous dominant, 50% heterozygous, 25% homologous recessive. the phenotypes would be 50/50
incomplete dominance
the lack of a dominant gene
what will the offspring show when an incomplete dominance occurs?
an appearance in between the phenotypes of parents (ex: red colour flowers, white colour flowers, show pink)
in incomplete dominance, both ____ interact to produce a new phenotype known as ______
genes, intermediate dominance
genes are the genetic make up, meaning they represent _______ letters, whereas alleles will represent just _____ letter (ex: AA vs A)
both, one
codominance
both alleles being found in the phenotype of the offspring
how do we represent blood typing?
I small a I small a for A, I small b I small b for B, I small a I small b for AB and lastly two small i’s for O
sex linked inheritance
trait passed down through genes on the sex chromosomes.
since men only have 1 X chromosome, are they more or less likely to show that trait passed down on the X chromosome?
more likely.
are females or males carriers of x linked traits?
females only
purpose of a pedigree analysis
used to look back into your ancestors to determine whether or not you might be a carrier for a genetic disease
what are autosomal?
the first 44 chromosomes, genetic makeup
how many sex linked chromies?
the last 2, XX female, XY male
genetic recombination
when DNA is shuffled between chromosomes to make new combinations of alleles
when does crossing over occur?
prophase of meiosis 1
the ______ the recombination %, the _________ the genes are on the chromosome
higher, farther apart
a linkage map is a genetic map based on ____________________
recombination frequencies
recombinant dna
combining genetic material from two different sources
law of segregation
during the formation of gametes, two copies of each gene separate so that each gamete carries only one copy, offspring inherit one gene from each parent
define genetics
the study of the transmission of characteristics from a being to their offspring
define a gene
the basic unit of heredity
