What are the three main events of the

sexual life cycle?

Meiosis, Gamete Formation and Fertilization

Gene

a portion of DNA that encodes a specific protein

Whose experiments uncovered the basic laws of inheritance?

Mendel’s  

What did Gregory Mendel do?

studied the inheritance patterns in pea plants 

Why did Gregory Mendel Study pea plants?

because they are easy to grow, develop quickly and produce abundant offspring.

Dominant allele

an allele that masks the expression of another allele

Recessive allele 

an allele whose expression is masked by another allele.

Achondroplasia

 the allele that causes a form of dwarfism is dominant, but it is very rare ---as is the allele that causes Huntington Disease.

A diploid cell...

can only have only two alleles for each gene

True or False: Two alleles in a diploid cell may be identical or different.

True

Homozygous

processing identical alleles of one gene

Heterozygous

processing different alleles of one gene.

When discussing generations of a species, a "P" generation refers to...

the parental generation

When discussing generations of a species, a "F1" generation refers to...

the first filial generation, which refers to the offspring of the P generation

When discussing generations of a species, a "P" generation refers to...

the second filial generation; which refers to the offspring of F1 generation

Chromosome

a dark-staining body that consists of a continuous double helix of DNA plus associated protein; each chromosome carries many genes.

True or False: Each chromosome carries only one gene.

False

Allele

an alternative form of a gene

Genotype

the allele combination in an individual

(what is written in your genes)

Phenotype

the observable expression of an allele combination

(what you see)

Brown (because the "B" is present)

Looking at eye color...

Brown (because the "B" is present)

Blue (because the dominant "B" is not present)

Wild type

the most common phenotype or allele for a gene in a population

Mutant

a phenotype or allele resulting from a change (mutation) in a gene.

Mutation

a change in a DNA 

Monohybrid

 a mating between two individuals that are both heterozygous for one gene

What is a Prunenett square used for?

Calculating the probability of each possible outcome in a genetic cross

Testcross

a mating between a homozygous recessive individual and an individual of an unknown genotype.

Law of segregation

It states that two alleles of each gene are packaged into separate gametes.

Dihybrid cross

a mating between two individuals that are each heterozygous for two genes.

What kind of cross allows you to track the inheritance of two genes at once?

Dihybrid crosses

Law of independent assortment

States that during gamete formation, the segregation of the alleles for one gene does not influence the segregation on the alleles for another gene.

Product rule

the chance that two independent events will both occur equals the product of the individual chances that each will occur.

Incomplete dominance

the heterozygous phenotype is intermediate between those of the two homozygote

Codominance

a heterozygote fully expresses two different alleles

Pleiotropic

a gene that has multiple phenotypic expressions

When does a Pleiotropic gene arise?

when one protein is important in different biochemical pathways or affects more than one body part or process.

Epistasis

one gene affects the expression of another, which may appear to disrupt Mendel’s law

Polygenic

the phenotype reflects the activities of more than one gene