Mendelian Genetics

Gene

- segment of DNA that contains the instructions for making proteins.

- involved in the expression of a trait.

- code that will be expressed

Chromatin

Cone part of chromosome

Allele

Different versions of gene

Capital

Dominant

Small

Recessive

Diploid Organism

Have two copies of each genes

Homozygous

Both alleles for a gene are the same

Heterozygous

Both alleles are different

Genotype

Genetic constitution of an organism

Phenotype

Observable physical expression

Dominant

allele that is phenotypically expressed; expressed by capital letter

Recessive

allele that is NOT expressed; represented by a small letter.

Gregor Mendel

Conducted crossbreeding experiments and observed traits in offspring.

Gene

Part of DNA, Located on a chromosome

Haploid

One set of chromosome

Diploid

Two set of chromosomes

Humans

Diploid with 46 chromosomes

Principle of Segregation

States that diploid organisms have two hereditary factors (alleles) for each trait. These alleles separate (segregate) during gamete formation

genes/alleles

(Principle of Segregation) Each gamete (sperm or egg) receives only one allele of a gene.  At fertilization, offspring inherit one allele from each parent.  The “factors” Mendel described are now called

Principle of Independent Assortment

States that during gamete formation, the segregation of one pair of alleles is independent of the segregation of another pair

Meiosis

Principle of Independent Assortment occurs during

Principle of Dominance

When an organism is heterozygous for a trait, only the dominant allele will be expressed in the phenotype

Complete Dominance

Shows how alleles are passed from parent to offspring

First filial generation

The types of gametes formed by each parent, and the combinations of these gametes to form the offspring is called

Second filial generation

If the F1s are used for the second round of genetic cross, the offspring is referred to as

Monohybrid Inheritance

Inheritance of a trait governed by only one gene

Dihybrid Inheritance

Involves the inheritance of two traits that are governed by two genes

Statistical probabilities

used to predict the outcome of mating or crosses

Sum rule

Applicable for MUTUALLY EXCLUSIVE events or events that can NEVER occur at the same time

“OR”

Product rule

Applicable for independent events or events that occur simultaneously

“And & Then”

Binomial Theorem

Applicable for mutually exclusive events with no particular order

Chi-Square Test

• used to test hypothesis regarding F1 ratios from crosses

• Test for goodness of fit, meaning it determines if an observed ratio is similar to expected ratio

Degree of Freedom

Used to determine the number of unique categories in a cross

cv<tv

no significant difference between the observed value and expected value

cv>tv

there is a significant difference between the observed value and expected value