2.  Gregor Mendal – discovered heredity is transmitted in discrete “units” later called genes.  James Watson and Francis Crick – showed DNA is a double helix

3.  Stored in the Nucleus  Determines the nature of each cell in the body and how it will function  Made up of nucleotides

4.  C = cytosine  G = guanine  T = thymine  A = adenine

5.  4 bases:  adenine can only pair with thymine (AT)  cytosine can only pair with guanine (CG)  The combination of base pairs cannot vary p. 172

6. 1. Which side of the ladder each base comes from 2. The order in which the base pairs occur along the ladder 3. The overall number of base pairs  These variations account for differences between species.  All organisms use just these 4 bases, but with different numbers and arrangements

7. Uncondensed DNA Chromosome P 176

9.  Condensed DNA  Rod shaped  Each sperm and each egg (gametes) contains 23 chromosomes.  The chromosomes contain genes (a certain length of the chromosome).  The fertilized egg (zygote) and all the body cells that develop from it (except the sperm cells and the egg) contain 46 chromosomes.

10.  Two types 1. Autosomes  22 pairs  numbered from largest to smallest. 2. Sex chromosomes:  1 pair (23 rd pair)  XX in females  XY in males

11. Karotype: picture of chromosomes P. 177

12. Question: A liver cell from a human male has: A) 22 pairs of autosomes, an X and a Y chromosome. B) 22 pairs of autosomes and two X chromosomes. C) 46 pairs of autosomes, an X and a Y chromosome. D) 23 pairs of autosomes and two X chromosomes. E) 23 pairs of autosomes, an X and a Y chromosome. Answer: A

13.  Each of us has two sets of chromosomes (homologous pairs) one from our mother and one from our father  Each homologous pair contains lengths of genetic information (genes)  Many matched pairs of genes are not exactly alike (alleles)  Differences in our genes account for our uniqueness (green eyes vs. blue eyes) Genes are a recipe. Alleles are different forms of the same recipe (e.g. chocolate cake and vanilla cake)

14. 23 Pairs = 46 chromosomes total in every cell of your body (except egg and sperm) HOMOLOGOUS PAIRS Gene for eye color (blue) Gene for eye color (green) allele

15.  Basic unit of genetic information  Determine nature and the function of the cell.  The human genes (about 120,000) are referred to as the human genome.  A genome is the full set of genes in each cell of an organism.

16.  A nuclear enzyme attaches to a segment of DNA causing nucleotide bonds to separate.  Transcription occurs resulting in messenger RNA (mRNA).  T is now U (uracil)  Transfer RNA (tRNA) initiates translation into amino acid.  Ribosomes move along the RNA bonding amino acids into polypeptide chains which make proteins.

17. mRNA tRNA NOTE TO STUDENTS: During the cell lecture we learned a part of this process, now we are just inserting one more step (translation using tRNA to tell the ribosome in the right language how to make proteins)

18. 1. Transcription: the transfer of information from a DNA molecule into mRNA molecule. 2. Translation: the transfer of information from an RNA molecule into a Polypeptide, in which language of the nucleic acids is translated into that of amino acids. Transcription and Translation

19.  DNA staircase unwinds and two chains separate  each chain attracts new biochemical material from the cell to synthesize a new and complementary chain  Ultimately a new cell is formed  Process is known as MITOSIS

20.  In the first step of mitosis, all chromosomes are copied, so that instead of 2 copies, the cell briefly has 4 copies of each chromosome.  Shortly afterwards, the cell divides in half, resulting in two cells each has a complete copy of the genetic information.  These cells grow larger and eventually undergo mitosis. Hint: Mitosis happens in “my toes” and my liver and my mouth etc.

21. MITOSIS Homologous pair copied

22.  Gametes:  Sex cells (ovum or sperm)  Diploid cells:  Cells having 2 copies of each chromosome  Haploid gametes:  Gametes having 1 copy of each chromosome

23.  testicles and ovaries.  A diploid cell (having 2 copies of each chromosome) undergoes a special form of cell division to create haploid gametes (having 1 copy of each chromosome).  An egg and a sperm fuse together to form a new diploid cell called zygote (a process called fertilization).

24. Meiosis

25.  Mitosis: each cell divides and duplicates itself exactly (46 chromosomes in each cell)  Meiosis: How reproductive cells (eggs and sperm) are produced  Results in gametes, cells that contain only 23 chromosomes

26.  Austrian Monk  Mathematical principles  Classical Genetics  Garden Pea as a model  “Basic units” in pairs

27. p. 210

28. Example: Pea is wrinkled or smooth

29.  Sexually Reproducing Organism  Cross-Pollination (2 different plants)  Self-Pollination (same plant)  The seeds in a pod of one of Mendel's pea plants are each the result of a separate fertilization event

30. Self-pollination occurs as pollen from the anthers falls on the stigma. 1 4 3 2 male anthers ovaries Seeds in ovary (peas in pod) Female stigma pollination = fertilization Pollen carry sperm Pollen falls

31. Parent generation (yellow seeds) (green seeds) 1 32 cross-pollination offspring (yellow seeds) x How to cross-pollinate: Mendel’s method

32.  Cross pollinate  Wait for Mature plant to develop  Observe characteristics

33.  Phenotype – The observable physical characteristics of an organism, as determined by genetic makeup  Genotype - The combination of alleles located on homologous chromosomes that determines a specific characteristic or trait.

34.  Dominant – when two different alleles are present, the one that is expressed. (Usually represented with a capital letter)  Recessive - when two different alleles are present, the one that is not expressed. (Usually represented with a lower case letter)

35.  Homozygous - with identical alleles at the same locus (location) on homologous chromosomes. (e.g. BB or bb)  Heterozygous - with two different alleles at the same locus on homologous chromosomes. (e.g. Bb)

37.  Monohybrid Cross  True-breeding stocks (homozygous)  P (Parental) generation  F 1  first filial generation Mendel’s Crosses

38.  Uses letters to represent genes  Capital letter denotes dominant gene and lowercase letter denotes recessive  E.g. a tall plant is dominant to a short  Use “T” to represent tall  Use “t” to represent short (not s)

39. HOW TO READ A PUNNETT SQUARE female gametes PpPp P p P p male gametes ppPp 12

40. YY yy Y y Y y Y Y y y Yy femalemale female gametes male gametes possible outcomes in fertilization P generation 1 2 3 4 5 F 1 generation

41. Question Cross an F1 heterozygous yellow pea with a F1 Heterozygous yellow pea Y y YyYy YY Yy yy Genotypic ratio of offspring? Phenotypic ratio of offspring?

42. YY yy Yy yy Y Y

43. YY yy Yy YY Yy yy yellowgreen three genotypes two phenotypes YY y y Heterozygous Homozygous

44. Applied Mathematical Principles

45. dominant allele recessive allele maternalpaternal maternalpaternalmaternalpaternal homozygous dominant heterozygous homozygous recessive yellow seeds green seeds

46. Yy YY Yy yy “pure” green F 1 generation F 2 generation self-pollination “pure” yellow mixed Yy YY Yy yy YYyy Yy YY F 3 generation YY Yy yy Yy YY Yy yy

47.  Heterozygous or Homozygous? AA _____Ee ____Ii _____mm _____  In guinea pigs, the allele for short hair is dominant. What genotype would a heterozygous short haired guinea pig have? _______  A heterozygous round seeded plant is crossed with a homozygous round seeded plant. (Round is dominant to wrinkled)  What percentage of the offspring will be homozygous dominant (RR)?

48.  A homozygous round seeded plant is crossed with a homozygous wrinkled seeded plant.  What are the genotypes of the parents?  What percentage of the offspring will also be homozygous? Questions:

49. P generation smooth yellow wrinkled green cross- pollination x F 1 generation 100% smooth yellow self-fertilization F 2 generation 315 9 101 3 108 3 32 1 smooth yellow wrinkled yellow smooth green wrinkled green ::: Dihybrid Cross 2 characters

50. F 1 cross with F 1 SY Sy sY sy SY Sy sY sy SSYY SSYy SsYy SsYy SSYy SSyy SsYy Ssyy SsYY SsYy ssYY ssYy SsYy Ssyy ssYy ssyy Phenotypic ratio?

51. P generation SSYY ssyy SY sy gametes F 1 generation 100% SsYy F 2 generation Pollen Egg SYSysYsy SY Sy sY sy x SS YY SS Yy Ss YY Ss Yy SS Yy Ss YYSs Yy SS yySs YySs yy Ss Yyss YYss Yy Ss yyss Yyss yy

52.  Who are the major players and what did they do?  DNA: what is it? What is it made from?  Nucleotide bases: For DNA, for RNA? What are they? How are they matched?  DNA replication, transcription, translation?  What can vary in DNA?  What is a Karotype?  What are chromosomes? How many do we have in our cells?

53.  What are genes? Alleles?  What is a genome?  What are mitosis and meiosis? Which cells undergo which process. What are the final results?  What are genotype, phenotype, homozygous, heterozygous, dominant, recessive? Example? Recognize?  What is the P and F1 generation?

54.  What are the products of a monohybrid cross? A dihybrid cross? Ratios?  Punnett squares