Ch11 - Mendelian Genetics (WIP) (copy)

Hybrid

Hybrid

Genetic makeup of an individual, having one capital allele and one lower case allele

Incomplete Dominance

Blending of two traits, such as a red flower and a white flower, producing a pink flower

Independent Assortment

Genes from separate traits can segregate separately from each other

Monohybrid Cross

Testing one hybrid trait such as Tt x Tt

F1

First generation

F2

Second generation

Genotype

Genetic makeup of an organism, indicated by letters, such as Yy, YY, or yy

Example of Heterozygous Alleles

Tt

Example of Homozygous Alleles

TT, tt

Mutiple Alleles

Genes having more than 2 alleles, such as rabbit fur

P

Parent generation

Rec 3:1

Ratio in a monohybrid cross

9:3:3:1

Ratio in a dihybrid cross

Alleles

Different forms of genes (Such as looking at a tall or short gene)

Co-dominance

Both alleles are expressed equally, such as checkered chicken feathers (Black hen, white rooster, making a black and white feathered chick)

Dihybrid Cross

Testing two hybrid traits such as TtRr x TtRr

Dominance

Some traits are dominant over others, indicated by a capital letter

Recessive

Trait masked by dominant gene

Phenotype

Physical characteristics of an organism, what it looks like

Polygenic Traits

Traits controlled by two or more genes, such as skin color

Probability

Likelihood that a trait will show up

If roan cows RW and roan bulls RW are bred, according to the principle of codominance, what percentage of the offspring are expected to be roan (Part red and part white)?

50%

Coat color in rabbits is determined by a single that has _____

Multiple alleles

Gregor Mendel used pea plants to study _____

The inheritance of traits

Offspring that result from crosses between true-breeding parents with different traits

Are called hybrids

The chemical factors that determine traits are called _____

Genes

Gregor Mendel concluded that traits are called _____

Inherited through the passing of factors from parents to offspring

When Gregor Mendel crossed a tall plant with a short plant, the F1 plants inherited…

An allele for tallness from the tall parent and a allele for shortness from the short parent

The principle of dominance states that…

Some alleles are dominant and some are

recessive

When Gregor Mendel crossed the true-breeding tall plants with true-breeding short plants, all the offspring are tall because…

the allele for tall plants is dominant

If a pea plant has the recessive allele which is green peas, it will produce…

Green peas if it does not also have a dominant allele for yellow peas

A tall plant is crossed with a short plant. If the tall F1 pea plants are allowed to self-pollinate…

Some of the offspring will be tall and some will be short

In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F2 generation because…

The allele for shortness and the allele for tallness segregated when the F1 plants produced gametes

In the P generation, a tall plant was crossed with a short plant. If the alleles did not segregate during gamete formation…

All of the F2 plants will be tall

When you flip a coin, what is the probability that it will come up tails?

1/2

The principles of probability can be used to…

Predict the traits of an offspring produced by genetic crosses

In the P generation, a homozygous tall plant is crossed with a homozygous short plant. This mating created in the F1 generation. The F1 generation self pollinated and produced the F2. Determine what the probability is that an F2 plant will be tall.

75%

Organisms that have two identical alleles for a particular trait are said to be…

Homozygous

If the Punnett square shown in Figure 11-1, which of the following is true about the offspring resulting from the cross?

All are expected to be tall

In the Punnett square shown in 11-1, the genotypes of the offspring are…

TT and Tt

A Punnett squares shows all of the following except…

The actual results of a genetic cross

If you made a Punnett square showing Gregor Mendel’s cross between true-breeding tall plants and true-breeding short plants, the square would show that the offspring had…

The genotype that was different from both parents

What principle states that during gamete formation genes for different traits separate without influencing each other’s inheritance?

Principle of independent assortment

The Punnett square in Figure 11-2 shows that the gene for pea shape and the gene for pea color…

assorted independently

What is the phenotype ratio or percentage of the offspring in the Punnett square shown in Figure 11-2?

9 round and yellow, 3 round and green, 3 wrinkled and yellow, 1 wrinkled and green

How many different allele combinations of R, r, and Y would be found in the gametes produced by a pea plant whose genotype was RrYY? Look for all combinations of each of these letters.

2

If a pea plant that is a heterozygous for round, yellow peas (RrYy) is crossed with a pea plant

2

incomplete dominance

codominance

polygenic traits

all organisms

Chromosomes

Are on the same chromosomes

The genes are probably located close to each other

Less likely they are to be inherited together

Pp x pp

Breed it with a homozygous recessive and see if all the offspring are purple

codominant

Ttpp

TtPp

6 tall and purple, 6 tall and green, 2 short purple, 2 short green

All will be tall and purple

3:1 Three tall one short

All will be round and yellow

Pink and white

2

You cannot always determine the genotype from the phenotype. It could be AABB or AaBb and look exactly the same

bbRR

White rough hair

BBRR, BBRr, BbRR, and BbRr

1/16

RI

In complete dominace

100%

50