Unit 5. Concept 1. Mendelian Genetics.

explain mendels law of dominance

a dominant (strong) allele will express itself over a recessive (weak) allele

explain mendels law of segregation

when chromosomes separate in meiosis, each gamete will

receive only one chromosome from each pair

explain mendels law of independent assortment

the assortment of chromosomes for one trait doesn't affect the assortment of chromosomes for another

what is a gene

basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA

what is an allele

a variation of the same sequence of nucleotides at the same place on a long DNA molecule

what are homologous chromosomes

Two chromosomes in a pair – normally one inherited from the mother and one from the father

who was gregor mendel

father of genetics/the pea guy

what were the conditions of mendels experiments

controlled plant breeding / only purebred plants / observed “either-or” traits

what is cross

the mating of two organisms

what does P stand for

parental generation

what does F1 stand for

first generation

what does F2 stand for

second generation

what is a dominant gene

a gene with and allele that will always have the trait shown

what is a recessive gene

a gene with an allele that will only show in absence of (fully) dominant allele

what is a genotype

the actual allele inherited

what is a phenotype

the physical traits and characteristics of an organism

what does homozygous mean

2 of the same allele (homo = same)

what does heterozygous mean

2 different alleles (hetero = different)

what is a punnet square

a diagram that shows the probability of inheriting traits from

parents with certain genes

complete this 2x2 punnet square and predict the phenotype and genotype ratios

Phenotype: 2:2 Genotype: 2:2

complete this 2x2 punnet square and predict the phenotype and genotype probability

Step 1: Write out your key in terms of what's dominant and recessive. Step 2: Determine the genotypes of the parents and write out the cross. Step 3: Figure out what kinds of gametes each parent can produce. Step 4: Set up a Punnett square for your mating.

what are the steps to solving dihybrid punnet squares

complete this 4x4 punnet square and predict the phenotype and genotype probability

complete this 4x4 punnet square and predict the phenotype and genotype probability

how can you use probability to determine the possibility of getting a specific genotypes

1. Perform a monohybrid cross for each individual gene

and determine the odds of getting each genotype (in

fraction form)


2. Multiply the odds to determine the odds of getting this and this and this and etc…