1. Genetics1. Genetics

The scientific study of heredity.

DNA – double helix.

Chemical pairs.

2. Inheritance2. Inheritance

Traits inherited by offspring from the parents.

What is the probability that a child from these two parents will have Cystic Fibrosis?

25%

3. Heredity3. Heredity

The process by which genes are transmitted between generations.

4. Fertilization4. Fertilization

Joining of male and female reproductive cells.

5. Self-pollinating5. Self-pollinating

Sperm in pollen fertilizes the eggs in the same flower.

6. True-breeding6. True-breeding

When plants self pollinate and produce offspring identical to themselves.

7. What did Gregor Mendel 7. What did Gregor Mendel do with pea seeds? do with pea seeds?

Cross-bred pea plants by joining male and female reproductive parts from two different plants.

1822 - 1884

8. Trait8. Trait

Specific characteristics of an organism. Flower color, height, etc.

9. P9. P

Parental generation

The original pair of plants

10. F110. F1

First filial generation

Offspring

11. Filius11. Filius

12. Filia12. Filia

13. Hybrid13. Hybrid

Offspring from the crossbreeding of parents with different traits.

X

=

14. Gene14. Gene

Chemical factors that determine traits.

15. Allele15. Allele

Different forms of a gene for a certain trait.Different forms of a gene for a certain trait.

16. What was Mendel’s first conclusion 16. What was Mendel’s first conclusion from his pea breeding from his pea breeding

experiments?experiments?

Biological inheritance is determined by factors (genes) that are passed from one generation to the next.

17. What was Mendel’s second conclusion?17. What was Mendel’s second conclusion?

Some alleles are dominant and some are recessive.

18. Dominant18. Dominant

Trait that will show up in the offspring.

19. Recessive19. Recessive

Trait that will show up in the offspring only if the dominant allele is not present.

20. Gametes20. Gametes

Sex cells

Sperm

Egg

21. Probability21. ProbabilityHow likely something is to happen.

If your flip a penny 10 times how many heads and how many tails would you get?

5 heads and 5 tails.

What is the probability of get heads?

50%

22. Punnett Square22. Punnett Square

A diagram that can be used to show the different gene combinations from two parents.

23. Homozygous23. Homozygous

Two identical alleles for a Two identical alleles for a particular trait.particular trait.

24. Heterozygous24. Heterozygous

Two different alleles for a Two different alleles for a particular trait.particular trait.

25. Phenotype25. Phenotype

Physical characteristics.The way an organism looks.

26. Genotype26. Genotype

The actual genes an organism has.

27. Incomplete Dominance27. Incomplete Dominance

Where an allele in a pair is not completely dominant over the other.

28. Codominance28. Codominance

Both alleles contribute to the phenotype or to the way the organism looks.

PUNNETT SQUARE

Genes: T = Tall (dominant) t = Short (recessive)

Alleles – both genes are for height.

Male (Tt) X Female (Tt)

TT Tt

Tt

T

T t

t tt

Genotype = Tt

Phenotype = Tall

3 Tall (75%)

1 Short (25%)

PetuniasR = Red (dominant)

W = White (recessive)RW (male) X RW (female)

R

W

R W

RR RW

RW WW

3 Red (75%)

1 White (25%)

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Incomplete Dominance

R = RedW = White RR X WW

R

WW

R

RW

RW RW

RW

4 Pink (100%)

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Codominance

R = RedW = White RR X WW

R

WW

R

RW

RW RW

RW

4 Red and White (100%)

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