GeneticsUnit Target: Model ways in which characteristics of one generation

relate to the next generation.

Learning Target: Explain the experiments of Gregor Mendel and his contributions to the

study of inheritance. (K).

Who is considered the father of genetics?

Gregor Mendel

Heredity characteristic

Gene an allele that masks another allele

Trait the different forms of genes

Allele an allele that is masked

Dominant the passing down of traits

Recessive segments of the DNA that carry the information to create proteins and cells

Which of the following are conclusions made by Mendel?

a. Genes are passed from one generation to the next.

b. Some alleles are dominant and others are recessive.

c. During gamete formation, alleles segregate from each other so that each gamete only carries a single copy of each gene.

d. Genes for different traits can segregate independently during the formation of gametes.

All are conclusion reached by Mendel

4. P stands for parental generation.

5. F1 stands for first filial

1 2

3

The previous slide is an example of:

1.The principle of independent assortment.

2.The principle of segregation.

The principle of segregation- the alleles for each gene segregated from each other so each gamete only had one allele for that particular gene

How does this picture demonstrate independent assortment?

The “R” alleles and “Y” alleles segregate independently from each other. They are not “attached” or dependent on each other.

Learning Target: Gather and analyze data on class traits. (S)

Tre has brown eyes and Ann Marie has blue eyes. What is the genetic trait being discussed?

Eye color

Is ear lobe attachment a continuous or discontinuous trait?

Discontinuous- you are either one thing (attached) or the other (unattached)

Give an example of a continuous trait.

Height, skin color

This girl has got some awesome genes!!!

Julia’s Dad Julia’s Mom Julia

Freckles yes yes yes

Cheek dimples

yes no yes

Free ear lobes

yes no no

1. Which statement is true about Julia and her parents?A. They all have at least one dominant allele for freckles.B. They all have at least one dominant allele for cheek dimples.C. They all have at least one dominant allele for free ear lobes.

A.

Truth or Baloney?

A trait that can be changed by human intervention is tongue rolling.

Baloney. A trait that can be changed by human intervention is hair color.

Can the environment affect genetic traits?

Yes- You may be tall enough to play basketball but unless you are taught how to the play the game you may not develop the athletic ability to play the game.

Learning Target: Complete a dissection of a flower to gather information on how sex cells contribute to the inheritance of genetic traits. (R)

Which # represents the male sex organ?

9 stamen

Which letter represent the female sex organ?

8 pistil

At what # would you find the male gamete?

3 the pollen is found on the anther

If the male gamete fuses with the female sex cell (7- ovule) what will have occurred?

Fertilization

Mouse sperm attempting to fertilize a mouse egg cell.

Learning Target: Differentiate between asexual and sexual reproduction. (R)

Sexual or Asexual?

Results in genetically identical offspring.AsexualResults in genetic variation.SexualFertilization is an example.SexualRegeneration of a body part is an example.Asexual

Learning Target: Interpret a table to differentiate between haploid and diploid cells. (S)

Organism Haploid # Diploid #

Onion 8 16

Earthworm 16 32

Human 23 46

What type of cells are haploid?

Gametes (sex cells)

Why are gametes haploid?

When fertilization occurs each gamete contributes their chromosomes to make a diploid organism.

Learning Target: Compare and contrast mitosis and meiosis. (S)

The number of cells produced by meiosis is two.

False: four

The cells produced during meiosis are genetically identical.

False: different

The cells produced during meiosis are called gametes.

True

The male gamete is dominant over the female gamete.

False: genetically equal to

Why is genetic variation important?

a. It allows for a biological diversity.

b. It allows for adaptation to take place over time as species respond to changing environmental conditions.

c. Both are correct

c.

What is taking place in the picture?

Crossing-over

What do each of the letters represent?

Alleles

Truth or Baloney?

Mitosis produces 2 cells that are genetically different.

Baloney- Alike

Mitosis is important in growth and repair of organisms.

True

Which picture shows meiosis?

The one on the left- it results in 4 gametes with ½ the number of chromosomes.

Use the rules of probability to solve genetics problems with Punnett squares. (R)

Truth or Baloney:

Probability is defined as the likelihood that an event will occur.

Truth

Who invented Punnett squares?

When flipping coins to model genetics, why did you use two coins?

To represent each parents contribution to passing down a trait.

What did heads and tails represent?

The two different forms of the gene (alleles).

Green leave are dominant to yellow striped leaves.

1. Is the parent generation homozygous or heterozygous?heterozygous

2. What is the phenotype ratio of green to yellow striped leaves in the offspring?3 green : 1 yellow striped

How is it possible for two plants with green pods to produce seeds for a plant that will have yellow pods?

The green plants each pass down a recessive allele.

Incomplete dominanceWhat is the genotype of the pink

flowers?

Rr

What is the genotype of the Red flower?

RR

What is the genotype of the white flower?

rr

Why is this incomplete dominance?

Because blending has taken place.

What type of genetic cross is represented by the lizard skin.

Codominance- Many colors are expressed. One color is not dominant over another.

What type of genetic cross is represented in the picture?

Another example of codominance. Isn’t nature cool?

Learning Target: Determine how the sex of an offspring is calculated. (R)

What is the genotype of a male?XY

What is the genotype of a female?

XX

What percent of offspring are female?

50%

Why does the male determine the sex?

The male carries a X and Y chromosome, the female only carriers X chromosomes.

Using Punnett squares determine how sex-linked traits are inherited. (R)

• Baldness is a recessive trait Is the mother bald?No

Is the father bald?Yes

Is the mother a carrier for baldness?No

What percent of female offspring will be bald?

0%

What percent of male offspring will be bald?

0%

Analyze a karyotype. (S)

What is this picture called?A karyotype

Is this a picture made from a male or female?

Male

Which chromosome pair are the sex chromosomes?

23rd pair

Pairs 1-22 are called?Autosomes

Does this person have a genetic mutation for Down’s syndrome?

no

Interpret a pedigree. (S)

What sex is represented by squares? MalesHow many children do the parents I 1 and I 2 have?5Red represents an individual with color blindness? Is person I 2 color

blind?NoIs person I 2 a carrier?Yes- it is the only way color blind female offspring are possible based on

her husbands genotype.