HOMEWORK FROM LAST CLASS: Complete the Genetics Practice Problems

worksheet Read over class notes and check out the

class blog: http://msoonscience.blogspot.com/

INTRODUCTION TO INTRODUCTION TO GENETICS - REVIEWGENETICS - REVIEW

Remember me? Who am I? • I’m Gregor Mendel, the “Father of Genetics”!

• I’m an Austrian monk who studied the inheritance of traits (characteristics) in pea plants.

Pea

VOCABULARY REVIEW

VOCABULARY REVIEW

_________ trait 1. A place on a chromosome that gives information for a protein

_________ recessive 2. A physical feature resulting from a genotype

_________ heredity 3. A form of a gene

_________ genotype 4. The combination of alleles for a trait; represented by 2 letters

_________ phenotype 5. The study of heredity

_________ dominant 6. The passing of traits from parent to offspring

_________ gene7. An allele that gets masked so it cannot be expressed (unless it

is paired with its counterpart allele)

_________ allele8. A characteristic or feature of an organism that can be passed

from parent to offspring

_________ genetics9. An allele that masks another, and is always expressed in the

phenotype

Match the following vocabulary words to the correct number.

VOCABULARY REVIEW - ANSWERS

8 trait 1. A place on a chromosome that gives information for a protein

7 recessive 2. A physical feature resulting from a genotype

6 heredity 3. A form of a gene

4 genotype 4. The combination of alleles for a trait; represented by 2 letters

2 phenotype 5. The study of heredity

9 dominant 6. The passing of traits from parent to offspring

1 gene7. An allele that gets masked so it cannot be expressed (unless it

is paired with its counterpart allele)

3 allele8. A characteristic or feature of an organism that can be passed

from parent to offspring

5 genetics9. An allele that masks another, and is always expressed in the

phenotype

Match the following vocabulary words to the correct number.

INCOMPLETE DOMINANCE• Genes are not always dominant or recessive—in some gene pairs, the genes are neither dominant nor recessive.

•Instead, these genes show incomplete dominance

Incomplete dominance: neither gene in a gene pair masks the other The traits carried by the 2 genes are blended

INCOMPLETE DOMINANCENeither the red gene

(R) nor the white gene (W) is dominant.

When the 2 genes are present in the same plant, a pink flower

results.

Both R and W are used (capital letters) because neither the

red gene nor the white gene is

dominant over the other.

Red

White

GENETIC PRINCIPLES1) Traits are passed on from one generation of

organisms to the next generation.

2) The traits of an organism are controlled by genes.

3) Organisms inherit genes in pairs, one gene from each parent.

Parent generation (P1)

1st filial generation (F1)

2nd filial generation (F2)

GENETIC PRINCIPLES4) Some genes are dominant, whereas other genes

are recessive.

T > t

5) Dominant genes hide recessive genes when both are inherited by an organism.

6) Some genes are neither dominant nor recessive. These genes show incomplete dominance.

PROBABILITYWhat is probability?The possibility, or likelihood, that a particular event will

take place.

Example: If you toss a coin, what are the chances that the coin will land heads up?

50% (either heads or tails)

The results of one event do not affect the results of the next.

Previous events do not affect future outcomes

PROBABILITYF1 cross (Bb x Bb)

What percentage of offspring are purebred purple?25% (1/4)

What percentage of offspring are hybrid purple?50% (2/4)

What percentage of offspring are purebred white?25% (1/4)

PROBABILITYF1 cross (Bb x Bb)

What percentage of offspring have the same genotype as the parents?50% (2/4)

What percentage of offspring have the same phenotype as the parents?75% (3/4)

ACTIVITY!

Paint your paper maché eggs and sperm!

INSTRUCTIONS

1) Find your pair’s egg or sperm.

2) Put newspaper down on your lab bench.

3) Paint your egg or sperm—get creative!

4) Place your painted egg or sperm on top of newspaper on the back table dry.

I will hang the eggs and sperm in the classroom when they are

dry!

GREGOR MENDEL’S PUNNETT SQUAREShttp://www.youtube.com/watch?

v=d4izVAkhMPQ&feature=player_embedded

HOMEWORK FOR NEXT CLASS:

Take a break! No homework over

Spring Break!

WORKS CITEDImages taken from the following sources:http://elleseconomy.com/http://mcclungsworld.com/2009/09/24/plants-squares-

and-stuff/http://www.life123.com/parenting/education/

probability-statistics/probability-problems.shtmlhttp://smabiology.blogspot.com/

2008_11_01_archive.htmlhttp://www.graphicshunt.com/health/images/

chromosome-885.htm