1. Genetics Is the branch of biology dealing with the principals of variation Who Am I?

2. Early ideas about Heredity There are only two things, science and opinion; There are only two things, science and opinion; the former begets knowledge, the latter ignorance. the former begets knowledge, the latter ignorance. …Hippocrates …Hippocrates

3. Hippocrates He believed that every part of the body produced the seeds of the parents which fused together to give rise to a new individual He believed that every part of the body produced the seeds of the parents which fused together to give rise to a new individual Hippocrates is known as the father of scientific medicine. Hippocrates is known as the father of scientific medicine. Hippocrates wrote the physicians oath called the Hippocratic Oath that establishes the standards, even today, how the physician should treat their patient. Hippocrates wrote the physicians oath called the Hippocratic Oath that establishes the standards, even today, how the physician should treat their patient.

4. Aristotle Aristotle was one of the two most important philosophers of ancient times (the other was Plato). He was born in Stagira in the north of Greece in 367 BC. When he was 17 he went to study at Plato's Academy in Athens, where he remained as a student and teacher for 20 years. For three years he served as Alexander the Great's private tutor. In 335 Aristotle returned to Athens, where he founded his school, the Lyceum. In 323, after the death of Alexander the Great, Aristotle felt that Athens was dangerous and moved to Chalcis, where he died at the age of 62. Aristotle was one of the two most important philosophers of ancient times (the other was Plato). He was born in Stagira in the north of Greece in 367 BC. When he was 17 he went to study at Plato's Academy in Athens, where he remained as a student and teacher for 20 years. For three years he served as Alexander the Great's private tutor. In 335 Aristotle returned to Athens, where he founded his school, the Lyceum. In 323, after the death of Alexander the Great, Aristotle felt that Athens was dangerous and moved to Chalcis, where he died at the age of 62.

5. Aristotle He believed that male and female semen mixed upon conception. He believed that male and female semen mixed upon conception. Sperm (angular) and mature fertilized egg of Ascaris worm

6. Harvey Embryo formed in stages and its development was affected by factors both inside and outside the mother (known as epigenesis) Embryo formed in stages and its development was affected by factors both inside and outside the mother (known as epigenesis) Epigenesis – Development of an individual and/or the external environment as a result from interaction between an individual’s GENES, external environment and internal environment. Epigenesis – Development of an individual and/or the external environment as a result from interaction between an individual’s GENES, external environment and internal environment. GENES

7. Antony van Leeuwenhoek Believed that embryos were preformed in the male semen and that the only involvement females has was in the uterus where the embryo developed Believed that embryos were preformed in the male semen and that the only involvement females has was in the uterus where the embryo developed

8. Pangenesis Males and females formed genes in every organ. Males and females formed genes in every organ. These genes moved through the blood to the genitals into the children These genes moved through the blood to the genitals into the children A theory of heredity proposed by Charles Darwin A theory of heredity proposed by Charles Darwin

9. Darwin Offspring had variations but was unable to explain the basis of heredity Offspring had variations but was unable to explain the basis of heredity He wrote the “Origin of Species” He wrote the “Origin of Species”

10. Blending Theory Sperm and egg mix together to give offspring that were a blend of the parent’s characteristics. Sperm and egg mix together to give offspring that were a blend of the parent’s characteristics. red flower + white Flower = PINK flower red flower + white Flower = PINK flower

11. Gregor Mendel Mendel's laws form the theoretical basis of our understanding of the genetics of inheritance. Mendel's laws form the theoretical basis of our understanding of the genetics of inheritance. Mendel made two innovations to the science of genetics: Mendel made two innovations to the science of genetics: 1. developed pure lines 2. counted his results and kept statistical notes

12. Mendel accomplished most of his work with garden peas, with clear cut characteristics so they could be easily followed Mendel accomplished most of his work with garden peas, with clear cut characteristics so they could be easily followed Each of his 7 chosen traits had only 2 possible variations: round and wrinked seeds, gellow and green colour, tall and short etc. Fig. 4.8 in your text Each of his 7 chosen traits had only 2 possible variations: round and wrinked seeds, gellow and green colour, tall and short etc. Fig. 4.8 in your text Seed Shape: Wrinkled and Round seeds.

13. What is an ALLELE One of the several alternative forms of a specific gene, each possessing a unique nucleotide sequence. One of the several alternative forms of a specific gene, each possessing a unique nucleotide sequence. For example, the gene for human eye color might be expressed in several forms: blue, brown, green, etc. When a person has one gene for blue eyes and one gene for brown, they have two alleles of that particular gene. Evolution proceeds by the change in the how frequent alleles appear in a population over the course of time. For example, the gene for human eye color might be expressed in several forms: blue, brown, green, etc. When a person has one gene for blue eyes and one gene for brown, they have two alleles of that particular gene. Evolution proceeds by the change in the how frequent alleles appear in a population over the course of time. tall and dwarf are the alleles for the height of a pea plant. tall and dwarf are the alleles for the height of a pea plant.

14. Mating Mendel mated pure (homozygous) individulas. Mendel mated pure (homozygous) individulas. He called this the P generation or the parent generation. He called this the P generation or the parent generation. What happened when Mendel crossed pure tall plants with pure short plants? Fig 4.9 What happened when Mendel crossed pure tall plants with pure short plants? Fig 4.9

15. Symbolic representation of the cross between tall and short pea plants Parental GenerationDDxdd Parental GametesD d F 1 GenotypeDd

16. New Terms Mendel coined two new terms. Mendel coined two new terms. Dominant Dominant the allele that expresses itself at the expense of an alternate allele; the phenotype that is expressed in the F1 generation from the cross of two pure lines the allele that expresses itself at the expense of an alternate allele; the phenotype that is expressed in the F1 generation from the cross of two pure lines Recessive Recessive an allele whose expression is suppressed in the presence of a dominant allele; the phenotype that disappears in the F1 generation from the cross of two pure lines and reappears in the F2 generation an allele whose expression is suppressed in the presence of a dominant allele; the phenotype that disappears in the F1 generation from the cross of two pure lines and reappears in the F2 generation

17. Punnett Square The Punnett square is a mathematical tool used by geneticists to show allelic combinations of gametes and to predict offspring ratios. The Punnett square is a mathematical tool used by geneticists to show allelic combinations of gametes and to predict offspring ratios. To fill in the squares bring the symbols down from the top of the columns and write that symbol in each square of the column. Also, bring the symbols across each row and write that symbol in each square of the row. These filled squares are the F1 generation's gene combinations. They are the result of the parent's donation of alleles. In this case, all the F1 generation is Gg or heterozygous. To fill in the squares bring the symbols down from the top of the columns and write that symbol in each square of the column. Also, bring the symbols across each row and write that symbol in each square of the row. These filled squares are the F1 generation's gene combinations. They are the result of the parent's donation of alleles. In this case, all the F1 generation is Gg or heterozygous.

18. Principal of Dominance When individuals with contrasting traits are crossed, the offspring will express ONLY the dominant trait (allele). When individuals with contrasting traits are crossed, the offspring will express ONLY the dominant trait (allele). Dominance is notes with uppercase letters (TT = tall) homozygous dominant Dominance is notes with uppercase letters (TT = tall) homozygous dominant and recessiveness is noted with lowercase letters (tt = short) homozygous recessive and recessiveness is noted with lowercase letters (tt = short) homozygous recessive Tt = tall but heterozygous or hybrid for that trait Tt = tall but heterozygous or hybrid for that trait

19. Same or different alleles? Homozygote Homozygote an individual which contains only one allele at the allelic pair; for example DD is homozygous dominant and dd is homozygous recessive; pure lines are homozygous for the gene of interest an individual which contains only one allele at the allelic pair; for example DD is homozygous dominant and dd is homozygous recessive; pure lines are homozygous for the gene of interest Heterozygote Heterozygote an individual that contains two different alleles at the allelic pair; for example the Dd heterozygote an individual that contains two different alleles at the allelic pair; for example the Dd heterozygote

20. Back to Mendel’s experiment The offspring he got from this mating of the P1 generation is called theF1 generation. The offspring he got from this mating of the P1 generation is called theF1 generation. He then mated 2 F1 individuals, and the result was a F2 generation He then mated 2 F1 individuals, and the result was a F2 generation What did he find? What did he find?

21. The following Punnett square shows the F2 generation created by selfing the F1 plants. Dd Union of gametesD DD (tall) Dd (tall) occurs at randomd Dd (tall) dd (dwarf)

22. Tall or Dwarf

23. This could also be done with smooth vs. round seeds

24. Findings of F1 matings Mendel saw that the F2 generation ressembled one parent from the P1 generation 75% of the time and the other parent of the P generation 25% of the time Mendel saw that the F2 generation ressembled one parent from the P1 generation 75% of the time and the other parent of the P generation 25% of the time This is known as the Medelian phenotypic ratio (3:1) This is known as the Medelian phenotypic ratio (3:1)

25. Genotype and Phenotype The Punnett Square allows us to visualize specific genetic ratios. The Punnett Square allows us to visualize specific genetic ratios. F2 Genotypic ratio: F2 Genotypic ratio: 1 DD : 2 Dd : 1 dd (or 3 D_ : 1 dd) 1 DD : 2 Dd : 1 dd (or 3 D_ : 1 dd) F2 Phenotypic ratio: 3 tall : 1 dwarf F2 Phenotypic ratio: 3 tall : 1 dwarf

26. What you see and what it really is? Phenotype Phenotype  the appearance of the trait in an organism Genotype Genotype the specific allelic combination for a certain gene or set of genes or genetic make-up of an organism. the specific allelic combination for a certain gene or set of genes or genetic make-up of an organism.

27. Allelic Expression When 2 alleles are present and there is a dominant one and a recessive one in your Punnett Square, the dominant allele may prevent the expression of the recessive allele in the PHENOTYPE (masks it from being seen) When 2 alleles are present and there is a dominant one and a recessive one in your Punnett Square, the dominant allele may prevent the expression of the recessive allele in the PHENOTYPE (masks it from being seen)

28. Law of Segregation Mendel's First Law Mendel's First Law Inherited traits are determined by pairs of genes (allelic pairs) Inherited traits are determined by pairs of genes (allelic pairs) These genes segregate in the gametes in the sex cells either the sperm or the egg from the male and female These genes segregate in the gametes in the sex cells either the sperm or the egg from the male and female

29. Probability Is the chance or likelihood of a particular outcome usually expressed as a ratio! Is the chance or likelihood of a particular outcome usually expressed as a ratio! The probability of one event or another event happening is the sum of their individual probabilities. The probability of one event or another event happening is the sum of their individual probabilities. EX: heads 50%, tails 50% EX: heads 50%, tails 50% Chances of heads or tails is 100% Chances of heads or tails is 100%