Chapter 12.1-12.3

Who is Gregor Mendel?

A polish Monk who studied the common pea plant to develop the study and the understanding of genetics

What did Gregor Mendel do to prevent self fertilization of a pea plant in his experiment?

he removed the anthers of over 20,000 plants in order to isolate how the plants germinated and fertilized

How did Gregor perform his experiment with the pea plants?

He made the first generation violet and white flowers, he crossed these flowers and found the F1 generation had only violet flowers, he crossed the F1 generation and found the F2 generation had white flowers present again alongside the violet flowers

What severed Gregor as a template for him to look at genetic variation and see how they are formed?

The seven features that were present in the pea pods

What are traits

They are a variation of physical appearances of a heritable characteristic

What did Gregor notice while crossing the pea plants?

He noticed a ratio was always forming, with the first generation have 100% of a trait and the second generation having 75% of that same trait

What did Gregor determine about traits from the ratio formed from crossing?

The most common trait was a dominant trait while the least common trait was a recessive trait

What are characteristics?

It is a heritable trait/feature (Ex. a flower color or a skin/hair color for humans)

What are genes?

they are the instructions for passing on genetics from an individual to their offspring

What are Alleles?

 They are recognized variants of genes that pass on a particular trait

What is a dominant trait?

A trait that occurs most commonly and produces the same physical appearance whether a person has two copies or one copy of the dominant trait

What is a recessive trait?

A trait that only shows up when a person has two copies of the recessive trait

Why is it that people have the same gene such as hair color but don’t produce the same color?

Everyone has a different allele, everyone has the same gene but not the same allele for that gene

What is a phenotype?

Physical traits expressed by an organism

What is a genotype?

It is the allele that is responsible for physical appearance

What is a homozygous individual?

An individual with identical alleles for a particular gene (uses two capitals or two lowercase, BB or bb)

What is a heterozygous individual?

An individual with two different alleles for a particular gene (Bb)

What law did Gregor Mendel create?

The law of inheritance that consists of three laws

What is the law of dominance?

It is the idea that if a dominant allele is present, the dominant phenotype will always be present in the organism and will conceal the presence of another allele for the same characteristic.

What is the law of segregation?

It is the idea that genes are segregated evenly into gametes, allowing for an offspring to have an equal likelihood of inheriting either the recessive or dominant gene from a parent

Who invented punnett squares and what do they do?

Invented by Reginald Punnett, helps predict possible genotypes and phenotypes of the offsprings

What is something that came from Punnett squares?

Test crosses

What do Test crosses do?

Allow the genotype of a plant to be determined based on its phenotype

How are test crosses performed?

A dominant individual with an unknown genotype is on one side while another with a homozygous recessive genotype on the other, the phenotype is at the center and used to determine whether the unknown genotype of the individual is either heterozygous or homozygous for the dominant trait

What is the law of independent assortment?

It is the idea that genes do not influence each other with regard to the sorting of alleles into gametes, and every possible combination of alleles for every gene has an equal chance of occurring

What do we use when more than one gene are coming together

a dihybrid cross

What does a dihybrid cross involve?

Involves two trihybrid or more, creating a ratio of 9:3:3:1

How does the law of segregation tie back into meiosis?

It allows for the genes to be segregated equally into the gametes

How does the law of independent assortment tie back into Meiosis?

It allows for the genes from both parents to have an equal chance of being inherited by their offsprings

What is a Pedigree Analysis?

It refers to the lineage of an animal and person, needing to go back multiple generations in order to know how things are spread