Genetics Unit

Honors Bio

Define a trait.

Are the characteristics passed down from parent to the offspring.

Define heredity.

The act of passing down traits from parents to the offspring

What is genetics the study of?

The study of heredity.

What are alleles?

The different forms of genes. (Dominant & Recessive)

What are dominant genes and how to they interact with recessive genes?

They are the stronger of the 2 genes, and they always over power the recessive genes in the traits of an organism.

What are recessive genes and how to they interact with dominant genes?

They are genes that show up less in an offspring, because they are always overpowered by the dominant genes.

What is a geneotype?

The letter combination for a specific gene.

Who father of genetics?

Gregor Mendel.

What is a phenotype?

The physical features that come with certain genes.

What does homozygous mean?

When the 2 letter that represent the genes are exactly the same (RR, rr).

What does heterozygous mean?

When the 2 letter that represent the genes are different. (Rr, rR).

What does a monohybrid cross look like?

What does a dihybrid cross look like?

What is a parental generation?

The first ever generation

What does f1 generation mean?

It’s the 1st generation of offspring (came from the parental generation).

What does f2 generation mean?

The 2nd generation of offspring (came from the f1 generation).

What are Mendel’s laws and how many are there?

There are 3 and it consists of the law of dominance, law of segregation, law of independent assortment.

Define the law of dominance.

Dominant genes mask recessive genes.

Define the law of independent assortment.

Genes are arranged independently of each other (demonstrated by FOIL)

Define the law of segregation.

During meiosis, 2 alleles split into 2 gametes (sperm / egg). Afterward another 1 allele (from another organism) comes and combines with 1 of the original alleles.

What is incomplete dominance?

When both physical features from the genotypes are expressed and are blended together (ex. white + red flower = pink flower)

What is co-dominance?

When both physical features from the genotypes are expressed but not blended together (ex. white fur + red fur cow = white cow with red spots)

What is complete dominance?

When the dominant (uppercase) genotype masks the recessive genotype (lowercase).

What are sex-linked traits?

A trait that is in the X chromosome and typically appears in males, since they only have 1 X chromosome. If it carries the trait, then there is no chance for another genotype to dominate it.