study guide genetics

A human baby has two X chromosomes.

Its sex is ______________.

A human baby has two X chromosomes. Its sex is FEMALE.

If it is XY it is a MALE. Remember: “if it’s got a Y, it’s a guy!”

The father of genetics is an Austrian monk named ____________________.

The father of genetics is an Austrian monk named GREGOR MENDEL.

Purebred dogs often show variations in coat color. This is an example of

____________________ dominance in genetics.

Purebred dogs (or horses)often show variations in coat color. This is an example of INCOMPLETE dominance in genetics.

Every sex cell has ____________________ allele(s) for

each trait.

Every sex cell has ONE allele(s) for each trait.

What is selective breeding?

Selecting plants or animals with the most desired traits to breed for

the next generation.

You are looking at four Tall pea plants. What are their phenotypes and

genotypes?genotype(s):_________________

phenotype(s): _______________

You are looking at four Tall pea plants. What are their phenotypes andgenotypes?genotype(s):TT OR Ttphenotype(s): TALLGenotype =genetic makeupPhenotype=what you can physically see

What possible genotypes will the offspring have if the parents' blood

types are O and AB?

What possible genotypes will the offspring have if the parents' blood

types are O and AB?O O

A AO AO

B BO BO

Remember the GENOTYPE is the GENETIC makeup so the GENOTYPES are the possible outcomes that are represented by the PAIRS of ALLELES in the Punnett square.

GENOTYPES: AO, BO

Mendel called plants that received different alleles for a trait from

each parent ____.

Mendel called plants that received different alleles for a trait from

each parent a HYBRID.

This car is a HYBRID of a gasoline and an electric car.

Blood type in humans is controlled by ____ alleles.

Blood type in humans is controlled by THREE alleles. (A, B, O )These combination of alleles gives us 4 different phenotypes of blood. (A,B,AB,O)They also give us 6 different Genotypes (AA,AO,BB,BO,AB,OO)

In a Punnett square, a capital letter stands for a ____ allele.

In a Punnett square, a capital letter stands for a DOMINANT allele

Pedigree?

PEDIGREE: tool for tracing a trait through a family

Heterozygous?

Heterozygous:organisms with two different alleles

for a trait

incomplete dominance

incomplete dominance:

when an intermediate

form is expressed in

offspring

polygenic inheritance?

polygenic inheritance:when more than two alleles control a traitTraits that are affected by more than one gene are called polygenic traits. The genes that affect a polygenic trait may be closely linked on a chromosome, unlinked on a chromosome, or on different chromosomes. Polygenic traits are often difficult for

geneticists to track because the polygenic trait may have many alleles. Also, independent assortment ensures the genes combine differently in gametes.

Therefore, many different intermediate phenotypes exist in offspring. Eye color (Figure below), and skin color are examples of polygenic traits in humans.

Eye color and skin color are examples of polygenic traits; they are influenced by more than one gene.

Homozygous?

Homozygous:when there are two alleles that are

exactly the same

KNOW how to do Punnett squares!KNOW your vocab!(especially homozygous, heterozygous, genotype, and phenotype) if you don’t KNOW these words you will NOT do well on the test. Do your BEST! There are not many grade opportunities left! Make your Mama PROUD!