Genetics and Cells? How do Genetics and Cells Relate?

The cell’s NUCLEUS contains all the

genetic information.

It’s called: DNA

Just to review…

Gregor Mendel

1851

Priest from a monastery in central

Europe.

High School teacher

Became curious about traits

He is known as, “The Father of

Genetics.”

A. Describe what Gregor Mendel discovered in his experiments about genetics.

Gregor Mendel

He noticed that the characteristics

of pea seeds and plants varied:

Round seeds or wrinkled seeds

Tall or short plants

White or purple flowers

Yellow or green pea pods

WHY???

A. Describe what Gregor Mendel discovered in his experiments about genetics.

He began cross pollinating plants with these characteristics.

First trait tested was HEIGHT.

Crossed a short plant with a tall plant.

Results:

Mendel found that -

All the pea plants grew to be tall

The short trait had disappeared

Gregor Mendel A. Describe what Gregor Mendel discovered in his experiments about genetics.

Gregor Mendel

Mendel ended up testing seven different traits.

A. Describe what Gregor Mendel discovered in his experiments about genetics.

Gregor Mendel

Gregor Mendel’s discoveries:

Inheritance of each trait is determined by "units"

or "factors" (now called genes) that are passed on

to offspring

An individual inherits one gene from each parent

for each trait

A trait may not show up in an individual but can

still be passed on to the next generation

A. Describe what Gregor Mendel discovered in his experiments about genetics.

Terms in Genetics

P1 Generation

The original parent or the true breeding plant.

F1 Generation

The offspring of the parent (P1)

F2 Generation

The offspring of the (F1) generation.

Your parents

You

Your Offspring

B. Define common terms in genetics

Terms in Genetics Allele –

Form of a gene

Usually represented with a

letter

Every trait has two alleles

that determine the

expression of the trait. One from mom, other from dad

height, color, shape, etc…

B. Define common terms in genetics

Terms in Genetics Dominant traits:

The trait that shows up ¾ of the time.

Shown with uppercase letters.

TT

Recessive traits:

The trait that shows up ¼ of the time.

Shown with lowercase letters

tt

B. Define common terms in genetics

Terms in Genetics

Purebred

Offspring of 2 parents with the same

characteristics/breeding Example: Angus calf from angus bull and cow

Example: Red carnation pollinated from 2 other red carnations.

Hybrid

Offspring from parents with different

characteristics/breeding Example: calf from hampshire boar and yorkshire sow

Example: Red carnation pollinated from a white carnation and a red carnation

B. Define common terms in genetics

Terms in Genetics Genotype:

The genetic composition of an individual

Phenotype:

How the alleles express themselves.

What you SEE

Ex. Two black calves might have the same phenotype, but different genotypes. One may be Heterozygous, (Bb)

One may be Homozygous, (BB)

B. Define common terms in genetics

Terms in Genetics

Homozygous:

Genes that possess two dominant alleles or

two recessive.

TT or tt

Heterozygous:

Genes that possess one dominant and one

recessive trait.

Tt

B. Define common terms in genetics

The Punnet Square

Mendel's pea plants

Tall = TT

Short = tt

T T

Tt Tt

Tt Tt

t

t

P1 Generation

F1 Generation

C. Demonstrate how a punnet square is used to determine heritability of traits

A method of calculating the chances of inheriting

a specific trait

The Punnet Square

Mendel's pea plants

Tall = Tt

Tall = Tt

T t

TT Tt

Tt tt

T

t

F1 Generation

F2 Generation

C. Demonstrate how a punnet square is used to determine heritability of traits

Dominance Offspring inherits the dominant trait

Example: Black is always dominant in cattle

D. Compare methods of inheritance such as: dominance, sex linked, co

dominance, and overdominance.

Methods of Inheritance

Sex-linked Genes

Some genes are located on the X or Y

chromosome and inherited by primarily 1

gender Color blindness

Hemophilia

Duchenne Muscular Dystrophy

Calico color in cats

D. Compare methods of inheritance such as: dominance, sex linked, co

dominance, and overdominance.

Methods of Inheritance

The sex of an animal is determined by the sex

chromosomes.

There are two types,

X shaped chromosomes

Y shaped chromosomes

Vertebrate males have a XY

Vertebrate females have a XX

E. Describe how genetics determine gender

How Gender is Determined

Every offspring has a 50/50 chance of being

male or female

Gender probablility:

Females ALWAYS give an X chromosome

Males give an X or Y

E. Describe how genetics determine gender

How Gender is Determined

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Artificial Selection: Humans control animal

breeding

Specific traits are chosen and

bred for

Natural Selection: Survival of the fittest

If the animal survives, it

reproduces

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture Varieties of corn…

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Round-Up Ready Corn

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Increased athletic ability & agility in horses

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Colors in Holstein cattle

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Seedless Watermelon

F. Give examples of how genetics are used to improve the quality of plant and

animal based agriculture.

Genetics in Agriculture

Seedless Bananas

Bell Quiz:

1. What is codominance? Give an example

2. What is incomplete dominance? Give an example

3. In a punnet square, what represents a dominant gene? A recessive

gene?

4. What scientist discovered how characteristics are passed from

generation to generation?

5. Draw a punnet square for a cross between a BB black bull and a Bb

black cow

6. What is heterozygous? Give an example

7. What is homozygous? Give an example

Bell Quiz:

1. Give an example of a homozygous dominant genotype

2. Give an example of a heterozygous genotype

3. Give an example of a homozygous recessive genotype

4. Describe what a sex linked trait is

5. Complete a punnet square for crossing a red carnation (RR) with a

White Carnation (R’R’)

Study for your Genetics

Test!!