Bellwork 11/24

1. Bellwork 11/24 Balance the following equations: Na + Br2  NaBr HgO + Cl2  HgCl + O2 Make sure you write the question and the full answer. You need to work out the problem

2. GENETICS 3.d. Describe heredity as the passage of instructions from one generation to another and recognize that heredity information is contained in genes, located in the chromosomes of each cell. (DOK 2) How traits are passed from parents to offspring through pairs of genes Phenotypes and genotypes Hierarchy of DNA, genes, and chromosomes and their relationship to phenotype Punnett Square calculations

3. Heredity Trait Genetics Fertilization Purebred Gene Alleles Dominant allele Recessive allele Hybrid Probability Punnett square Phenotype Genotype Homozygous Heterozygous Codominance Vocabulary words for Genetics unit. The definitions are in the book. We will have a vocabulary quiz tomorrow.

4. Bellwork 11/25 – turn in when finished & study for quiz Which of these would happen to the cell if cellular respiration stopped? A. It would not have the energy it needs to perform its functions. B. It would grow larger because it would not be able to dispose of wastes. C. It would have to access backup energy trapped in the chemical bonds of food. D. It would no longer be able to passively transport materials across its cell membrane.

5. Heredity • The passing of physical characteristics from parents to offspring

6. Trait • A characteristic that an organism can pass on to its offspring through its genes • Height • Eye color • Hair color

7. Genetics • The scientific study of heredity • Discovered by Gregor Mendel • Experimented with pea plants

8. Fertilization • The process in which an egg cell and a sperm cell join to form a new organism

9. Purebred • The offspring of many generations that have the same trait • Purebred short pea plants always come from short parent plants • Purebred German Sheppard dogs always come from German Sheppard parents • There will be no other species of that organism in the blood line

10. Gene • Factors that control a trait

11. Alleles • Different forms of a gene • An organism’s traits are controlled by the alleles it inherits from its parents. • Some alleles are dominant, while other alleles are recessive

12. Dominant allele • One whose trait always shows up in the organism when the allele is present • Always represented by a capital letter

13. Recessive allele • One whose trait is hidden whenever the dominant allele is present • A trait controlled by a recessive allele will only how up if the organism does not have the dominant allele • Always represented by a lower case letter

14. Hybrid • Has two different alleles for a trait • An organism that is heterozygous for a particular trait

15. Codominance • The alleles are neither dominant nor recessive • As a result, both alleles are expressed in the offspring

16. DNA • Deoxyribonucleic Acid • Contains the biological instructions that make each species unique • Carry the genetic code • Located in the nucleus of a cell • Made up of genes which are located on chromosomes

17. DNA • Made up of genes which are located on chromosomes that are found in the nucleus of a cell • DNA carries the heredity material that makes up your unique characteristics

18. Phenotype • An organism’s physical appearance or visible traits • Blonde hair • Brown eyes • Tall • Widows peak

19. Genotype • An organism’s genetic makeup or allele combinations • GG • Gg • gg

20. Homozygous • An organism that has two identical alleles for a trait • SS • ss

21. Heterozygous • An organism that has two different alleles for a trait • Rr • Mendel used the term hybrid to describe heterozygous organisms

22. Probability • A number that describes how likely it is that an event will occur

23. Punnett Square • Is a chart that shows all the possible combinations of alleles that can result from a genetic cross • In a genetic cross, the allele that each parent will pass on to its offspring is based on probability

24. Filling out Punnett Squares • Start by drawing a box and dividing it into 4 squares

25. Filling out Punnett Squares • Write the male parent’s alleles along the top of the square and the female parent’s alleles along the left side

26. Filling out a Punnett Square • Copy the female parent’s alleles into the boxes to their right and the male parent’s alleles into the boxes beneath them

27. Filling out a Punnett Square • The completed Punnett square shows all the possible allele combinations in the offspring

28. Examples • A pea plant with round seeds has a genotype of Rr. You cross this plant with a wrinkled seed plant, genotype rr. What is the probability that the offspring will have wrinkled seeds?

29. Examples • In guinea pigs, the allele for black fur (B) is dominant over the allele for white fur (b). In a cross between a heterozygous black guinea pig (Bb) and homozygous while guinea pig (bb), what is the probability that an offspring will have white fur?

30. Examples • In rabbits, the allele for a spotted coat is dominant over the allele for a solid-colored coat. A spotted rabbit was crossed with a solid-colored rabbit. The offspring all had spotted coats. What are the probable genotypes of the parents? Explain.

31. Examples • A long haired rabbit (Bb) is crossed with a short haired rabbit (bb). Using a Punnett square, what is the probability for all phenotypes and gentotypes?