Genetics

1. Genetics

2. Genetics is the branch of science that studies _________. • ________ is the passing of traits from parents to offspring. heredity Heredity

3. GregorMendel monastery • Did his research in the __________ • Born in 1822 in __________ • Wanted to figure out why some _______ showed up more often then others • Studied garden _____ plants Austria traits pea

4. Why Pea Plants? Self Pollinating • ____ _________ -has both male and female reproductive structures on the same plant • Able to grow ____ ________ plants. Plants self pollinated therefore were exactly like the parent. • _____ __________-pollen from one plant fertilizes the ovule of a different plant • Carried by _______ or _________ true breeding Cross Pollination wind insects

6. feature forms Characteristic - A __________ that has different _______ in a population. • Mendel studied only one pea characteristic at a time. • _______ - are different forms of a characteristic • __________ or ____________ Traits Dominant recessive

7. Pea Plant Traits Mendel Studied

8. Mendel’s First Experiments • Mendel crossed pea plants to study seven different characteristics. • Mendel got similar results for each cross. One trait was always present in the first generation, and the other trait seemed to disappear. • Mendel called the trait that appeared the dominant trait. The trait that seemed to fade into the background was called the recessive trait.

9. Dominant Trait first • A trait that is always ______ in the organism. • Dominant alleles are symbolized with __________ letters capital

10. Recessive Trait masked • Is _________ or hidden in the presence of a dominant trait. • Recessive alleles are symbolized with _________ letters • _______ - relationship between two different numbers that is often expressed as a fraction. lowercase Ratio

11. Traits and Inheritance • ________-Instructions for inherited traits • One from each __________ • _________-different forms of a gene • __________-an organism’s appearance • __________-an organism’s genetic makeup Gene parent Alleles Phenotype Genotype

12. Homozygous two recessive Purebred • _______________ an organism that has _____ dominant or two _______ alleles. ____________ example: if T = tall and t = short then TT or tt • _______________ an organism has both a __________ AND a ___________ allele. _________ example: if T = tall and t = short then Tt Heterozygous dominant recessive hybrid

13. Heredity In Plants Reading 1. The passing of characteristics from parents to offspring is known as ____________ 2. The scientific study of heredity is called __________ 3. The offspring of two purebred plants with contrasting traits is called a _____________ 4. A _________ trait will occur more often then a ____________ trait. heredity genetics hybrid dominant recessive

14. More About Gregor Mendel Reading 1. How long was the experiment expected to last? The experiment was expected to last seven years. 2. Why use pea plants? Because they were able to self-pollinate and were easy to grow.

15. 3. Why was the F1 generation referred to as being hybrid tall? There was one dominant and one recessive allele. The recessive allele is hidden.

16. Chapter 5 Section 2

17. In __________ reproduction, only one parent cell is needed for reproduction. • In __________ reproduction, two parent cells join together to form a new individual. • Human body cells have ___ chromosomes. asexual sexual 46

18. sex cells 23 • Human _____ _____ have only ___ chromosomes-half the usually number. Male sex cells are called _____. Female sex cells are called ________. • _________produces new sex cells with half the usual number of chromosomes. • Genes are located on __________. sperm egg Meiosis chromosomes

19. Sex chromosomes • ____ ____________ carry genes that determine whether the offspring is male or female. • Females have _____ chromosomes. • Males have _____ chromosome and ____ chromosome. • THINK! Explain the difference between sex cells and sex chromosomes. 2 X 1 X 1 Y

20. 10. THINK! Explain the difference between sex cells and sex chromosomes. • Each sex cell (egg or sperm) contains half of all the chromosomes, including one sex chromosome. The sex chromosome genes are what determine whether an offspring will be male or female.

21. Punnett Squares

23. DNA • Chromosomes are made of ______ • Genes must be able to supply __________ for cell processes and for ________ cell structures • ________ and ______ build models of DNA. They conclude that DNA resembles a twisted ladder shape known as a ______ _____ • The structure of DNA can be compared to a _______ ______ instructions building Watson Crick double helix

25. Incomplete Dominance • ___________ __________ is when a trait appears to blend together but each allele has his own degree of influence.

26. environment amount of food • Many things in your also influence how you grow and develop • Example:

27. Chapter 6 Section 2

28. Proteins How tall you are Eye color • ___________ act as a chemical messenger • __________ occur when there is a change in the order of bases in a organism’s DNA • The three possible consequences to changes in DNA include: • __________________ • __________________ • __________________ Mutations an improvement no change at all a harmful change

29. mutagen • A ________ is anything that can cause a mutation in DNA • _________________ is a disease that affects red blood cells • Genetic __________ provides information and counseling to couples who wish to have children but are worried that they might pass a disease on to their ________ Sickle Cell Anemia counseling children

30. pedigree • A __________ is a diagram for tracing a trait through generations of a family.

31. selective breeding In _________ ________ organisms with desirable characteristics are mated to produce a new breed.

32. genetic engineering This process of _________________ allows scientists to transfer genes from one organism to another.

33. Genes Video