Genetics

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

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

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

Characteristic   A __________ that has different _______ in a population   _______ different forms of a characteristic – –__________ or ____________ feature forms Traits Dominantrecessive

Dominant Trait   The trait present in the _______ generation   Dominant alleles are symbolized with __________ letters first capital

Recessive Trait   The trait that seems to _______ into the background   Does NOT show up as _______   A trait that _________ in the second generation after _____________ in the first generation when parents with different traits are bred   Recessive alleles are symbolized with _________ letters recede often reappears disappearing lowercase

RATIO  Relationship between two different numbers that is often expressed as a fraction

Traits and Inheritance   ________-instruction 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

  _______________ an organism that has _____ dominant or two _______ alleles. ____________   _______________ an organism has both a __________ AND a ___________ allele. _________ Homozygous two recessive Purebred Heterozygous dominant recessivehybrid

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?  Gregor Mendel used pea plants because they were able to self pollinate and easy to grow.

3. 3. Why was the F 1 generation referred to as being hybrid tall?   There was one dominant and one recessive allele. The recessive allele is hidden.

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

Chapter 5 Section 2

1. 1. 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

4. 4. 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 __________. sex cells23 sperm egg Meiosis chromosomes

7. 7. ____ ____________ 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. Sex chromosomes 2 X 1 X 1 Y

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.

Punnett Square Directions

  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 ______ _____ DNA instructions building WatsonCrick double helix

  The structure of DNA can be compared to a _______ ______   ___________ __________ is when a trait does not blend together but each allele has his own degree of influence.   Many things in your ___________ also influence how you grow and develop – –Example: twisted ladder Incomplete Dominance environment amount of food

Chapter 6 Section 2

  ___________ 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: – –__________________ Proteins How tall you are Eye color Mutations an improvement no change at all a harmful change

  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 ________ mutagen Sickle Cell Anemia counseling children

  A __________ is a diagram for tracing a trait through generations of a family.   In _________ ________ organisms with desirable characteristics are mated to produce a new breed.   This process of _________________ allows scientists to transfer genes from one organism to another. Pedigree selective breeding genetic engineering

Genes Video