Classical Genetics Flashcards
one of a pair of genes
allele
the trait that is expressed even when combines w/ other alleles
dominant
must be two of these alleles present in order for this trait to be expressed
recessive allele
individual that is genetically pure for a given trait
possessed two identical alleles
homozygous
individual with two different alleles for a given trait
heterozygous
outward appearance of an individual w/ respect to a given trait
phenotype
genetic characteristics of an individual with respect to a given trait
genotype
if two individuals with contrasting, pure-breeding traits are crossed, the trait that is expressed phenotypically in the offspring is the dominant trait
the trait that remains hidden is recessive
Mendel’s Law of Dominance
every normal diploid organism has two alleles for each inherited trait (one from the maternal parent and one from the paternal parent)
during meiosis, these alleles segregate, forming gametes that carry only one allele for a given trait
in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is 3:1
Mendel’s Law of Segregation
in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is _____
in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is 3:1
in a monohybrid cross b/w 2 heterozygotes, the genotypic ratio of the offspring is ______
1 : 2 : 1
during meiosis, all allelic combinations are distributed to games w/ equal probability, and the distribution of one pair has no effect on the distribution of another pair (if the genes are unlinked)
Mendel’s Law of Independent Assortment
according to mendel’s law of independent assortment, in a dihybrid cross for unlinked genes 1 and 2, the phenotypic ratio of the offspring is _______
9 (dominant for both) : 3 (dominant for 1, recessive for trait 2) : 3 (recessive for trait 1, dominant for trait 2) : 1 (recessive for both traits
type of inheritance
usually both males and females affected
if it skips a generation, then the gene is recessive
autosomal recessive inheritance
type of inheritance
usually both males and females affected
if it doesn’t skip a generation, then it is dominant
autosomal dominant inheritance
type of inheritance
usually be more affected males than females
no male-male transmission
males have a better chance of expressing the trait bc they only have 1 of this type of chromosome from the mother, so genes linked to that chromosome will be expressed
may be masked by dominant gene on female’s other 1 of these chromosomes
X-linked (sex-linked) recessive inheritance
blood type expresses the A antigen has Anti-B antibody can donate to A and AB can receive from A and O
type A blood
blood type expresses B antigen anti-A antibody can donate to B and AB can receive from B and O
type B blood
blood type does not express antibodies has A and B antigens can donate to AB can receive from A, B, AB, and O (*Universal acceptor)
type AB blood
blood type has anti-A and anti-B antibodies does not express antigens can donate to A, B, AB, and O (Universal donor) can receive from O
type O blood
probability of producing a genotype that requires multiple events to occur = the ________ of the probability of each event
product
probability of producing a genotype that can be the result of multiple events = the _____ of each probability
sum
_______ during prophase I of meiosis I can unlink genes
crossing over
genes are most likely unlinked when _________
far apart
