1. What is genetics? Study of heredity 2. What is fertilization? Joining of male and female sex cells (gametes)

1. What is genetics?

• Study of heredity

2. What is fertilization?

• Joining of male and female sex cells (gametes)

3. What does it mean for a plant to be “true breeding?”?

• If plant pollinates itself, it will produce offspring that are identical to itself

Pollen (male) Carpel (female)

4. How did Gregor Mendel cross-pollinate pea plants? Why did he want to do this?• He put pollen from

one plant on the flower of another plant.

• To see what would happen when plants with different characteristics produced offspring together.

5. What is a trait? Give an example of one of your traits.• Specific characteristic of a living thing.• Hair color, eye color, height, body shape, etc.

6. What is a hybrid? Why are some new cars called hybrids?• Offspring of parents with different traits.• Hybrid cars are a mix of both gas and electric cars.

7. What is meant by P, F1, and F2 generations? If you belong to an F2 generation, name two people who are part of your F1 and P generations.

• P = Parent, F1 = offspring of parents, F2 = offspring of F1.

• If you are F2, your parents are F1 and your grandparents are P.

8. What is a gene?• Chemical factors that determine traits• section of DNA that holds genetic code for a particular

trait. • Ex: a gene for hair color, a gene for eye color, etc.

9. What are alleles? Look at the table at the bottom of p. 264 and identify four different alleles that Mendel studied in seeds of pea plants.

• Different forms of a gene for a specific trait.• Allele for round seeds or wrinkled, yellow seeds or green,

gray seed coat or white, smooth pods or constricted.

Seed Shape

Flower Position

Seed CoatColor

Seed Color

Pod Color

Plant Height

PodShape

Round

Wrinkled

Round

Yellow

Green

Gray

White

Smooth

Constricted

Green

Yellow

Axial

Terminal

Tall

Short

Yellow Gray Smooth Green Axial Tall

10. What does an organism look like when it has both a dominant allele and a recessive allele for the same trait? Give an example.• It will show the trait of the dominant allele, not the

recessive one.• If pea plant has a dominant gene for purple flowers (P)

and a recessive gene for white flowers (p), the flowers will be purple.

Dominant allele(purple flowers)

Recessive allele(white flowers)

11. What is segregation? What happens to alleles during segregation?

• Separation of alleles• Alleles get separated

in the formation of gametes (sex cells).

12. Look at the diagram at the bottom of p. 265. How did Mendel explain the disappearance of short pea plants in the F1 generation and their reappearance in the F2 generation?• The F1 generation had both alleles for short and tall plants.

Since allele for tallness is dominant, all plants were tall. • Some plants in F2 generation only had alleles for shortness,

so they were short.

P generation F1 generation F2 generation

13. Copy the diagram on p. 266 and use it to explain why only about one fourth of Mendel’s F2 plants were short while the rest were tall.

• T = tall allele (dominant), t = short allele (recessive)

• ¼ plants had TT combo, so were tall

• ½ plants had Tt combo, so were tall (T is dominant)

• ¼ plants had tt combo, so were short