GENETICS: HOW WE BECOME WHO WE ARE TO

BE2.22.10

Maria James

1.17.12 Genetics bell ringer: pass

coach p. 68-71

Connections—your family

Decode the terminology—what does it all mean?

Word wall cards—2-3 per unit.

Closure: q/a Exit cards

SC Standard(s): 7-2.5 Summarize how

genetic information is passed from parent to offspring by using the terms genes, chromosomes, inherited traits, genotype, phenotype, dominant traits, and recessive traits.

7-1.2 Generate questions that can be answered through scientific investigation.

SpongeBob genetics 1. For each genotype below, indicate

whether it is a heterozygous (He) OR homozygous (Ho).

TT ___ Bb ___ DD ___ Ff ___ tt ___ dd _____ Dd ___ ff ___ Tt ___ bb ___ BB _____ FF ___ Which of the genotypes in #1 would be

considered purebred? _______________________________

Which of the genotypes in #1 would be hybrids? ________________________________________

2. Determine the phenotype for each genotype using the information provided about

SpongeBob.

Yellow body color is dominant to blue. YY ________ Yy ________ yy _________ Square shape is dominant to round. SS ________ Ss _________ ss ________

3. For each phenotype, give the genotypes that are

possible for Patrick. A tall head (T) is dominant to short (t). Tall = _______ Short = ________ Pink body color (P) is dominant to yellow

(p). Pink body = ______ Yellow body = ______

List some family members with these common

characteristicstrait Who has it?

Brown hair2nd toe longer than 1st toe

hitch-hikers thumbwidows peak

hair on middle knucklesbrown eyes

rolling tongueattached or unattached ear lobes

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Remaining.

Offspring inherit genetic traits from their parents. These traits are passed on to the offspring in the genetic material from each parent. Many genes that cause these traits

have dominant and recessive forms.

– Under what conditions does an individual express a dominant trait from its parents?

– Under what conditions does an individual express a recessive trait from its parents?

Bell ringer

Heredity 1. Offspring (new organisms or

babies) may have the same physical characteristics, or traits, as their parents because genetic information (DNA) is passed from parent to offspring during sexual reproduction.

Chromosomes2. Each sex cell (egg or

sperm) of the parent organism (plant or animal) contains one-half of the genetic material needed to create a new organism.

3. Heredity is the passing of traits from one generation to another, or inheritance.

4. A structure found in the nucleus of a cell that contains the genetic information (DNA).

Genes are… 5. A segment of DNA found on a

chromosome that determines the inheritance of a particular trait.

6. Genes are responsible for the inherited characteristics that distinguish (separate) one individual from another.

7. Genes for a specific trait generally come in pairs.

8. One gene from the pair is called an allele.

9. Genes may be expressed in two different forms. A. Genotype—the set

of genes carried by the organism. What we have

B. Phenotype—the physical expression of the genes. What we see

Inherited Traits Characteristics that are passed from parent to

offspring. Examples of inherited traits may be eye color, eye shape, hair type, or face shape.

Some inherited traits are dominant and some are recessive. Dominant trait – A trait that will always be expressed

in the phenotype. Alleles for dominant traits are represented by capital letters.

Recessive trait – A trait that will only be expressed in the phenotype if two recessive alleles are present. In the presence of a dominant trait, the recessive trait will not be expressed. Alleles for recessive traits are represented by lowercase letters.

Sexual Reproduction and DNA Each sex cell (egg or sperm) of the

parent organism (plant or animal) contains one-half of the genetic material needed to create a new organism.

Heredity is the passing of traits from one generation to another, or inheritance.

Chromosomes are found in the nucleus of a cell that contains the genetic information (DNA).

Create your own….

genotypes Row 1Hair texture

Row 2Hair color

Row 3Eye color

dad Cc bb Bb

mom CC Bb Bb

C-curly, c- straightB- brown, b- blondeB- brown eyes, b-blue eyes

Mendel’s peas

gg

Mom’s genotype ____gg_____Dad’s genotypes ___Gg____Mom’s phenotype _yellow___Dad’s phenotype _green____Each types probability – Gg– 50%genotype gg- 50%Each types phenotype –green-- 50%

yellow– 50%Homozygous– momHeterozygous--dad

G

g

g

g

Gg

Gg gg

x

Your titleMom’s genotype _________Dad’s genotypes _______Mom’s phenotype ____Dad’s phenotype _____Each types probability – ___–%genotype ____- %Each types phenotype –_____-__%

______–__%Homozygous– ______Heterozygous--_____

_

_

_

_

x

Tomatoes, and more

Ex.s mom dadtomato TT Ttfreckles Ff FFdiabetes dd Dd

Notes 1. DNA is in chromosomes inside of the nucleus.2. The nucleus is the control center of the cell.3. DNA has all of the genetic information.4. DNA has the code for all genetic information.5. Genetic traits are physical characteristics

that are passed from parent to offspring. 6. Sexual reproduction means ½ of the

information came from each parent. 7. Sex cells (f=egg cell, m= sperm cell) each

contain ½ of the genetic information . It is combined to produce the offspring.

8. The chromosome segments that control each trait are called genes.

9 Some traits are controlled by more than 1 gene.

10. Genes for traits come in pairs.11. Each ½ of the gene pair is called an

allele. 12. Genes may be expressed in 2 different

forms. A. genotype—set of genes that you carryB. Phenotype– the expression of genes (the

traits that you see.)

13. Examples of inherited traits may be eye color, eye shape, hair type, or face shape.

14. Some inherited traits are dominant and some are recessive.A. Dominant trait – A trait that will always be

expressed in the phenotype. Alleles for dominant traits are represented by capital letters.

B. Recessive trait – A trait that will only be expressed in the phenotype if two recessive alleles are present. In the presence of a dominant trait, the recessive trait will not be expressed. Alleles for recessive traits are represented by lowercase letters.

Tomatoes, and more

Ex.s mom dadtomato TT Ttfreckles Ff FFdiabetes dd Dd

tomatoes freckles diabetes

Tomatoes, and more

F f

F FF Ff

F FF Ff

d d

D Dd Dd

d dd dd

Ex.s mom dadtomato TT Ttfreckles Ff FFdiabetes dd Dd

freckles

tomatoes

diabetes

Punnett Squares15. In a Punnett square, the top of the

table shows the alleles provided by one parent.

16. The alleles for the other parent are placed along the left side of the table.

17. One allele from each parent is placed in the individual squares, forming a new gene pair.

18. The individual squares show the possibilities of allele pairs (genotypes) in the offspring.

19. If the two alleles are the same (TT or tt), the genotype is considered purebred. If the two alleles are different (Tt), the genotype is considered hybrid.

20. This example shows the inheritance of a single characteristic (height). A cross that shows the inheritance of a single characteristic is known as a monohybrid cross.

Let’s make an alien…Alien Traits Heads Tails selected

Eye color brown green# of eyes 2 3

Body Color blue purpleHead Shape square round

Number of antennae 2 3Number of legs 6 10Position of legs Under body Sides of body

Number of wings 1 2Has a tail yes No

Has body covering (like fur, scales, or

feathers)

yes No

Mouth has beak lips

Making your model Must be 3-d. Must match your selection sheet. Must be made of recycled materials. Due on 2/16.