Introduction to Heredity PDF

Warm-Up ? Introduction to Heredity Lesson Question Lesson Goals Examine the contributions made by Gregor Mendel to the field of genetics. W 2K Explain how traits are inherited. Distinguish dominant and Differentiate between alleles. and phenotype. Words to Know Write the letter of the definition nex...

Warm-Up ? Introduction to Heredity Lesson Question Lesson Goals Examine the contributions made by Gregor Mendel to the field of genetics. W 2K Explain how traits are inherited. Distinguish dominant and Differentiate between alleles. and phenotype. Words to Know Write the letter of the definition next to the matching word as you work through the lesson. You may use the glossary to help you. homozygous A.  the study of heredity alleles B.  having two identical alleles for a particular trait genetics heterozygous heredity C.  the different forms of a gene for a given trait D.  an organism’s allele combination E.   the passing of traits from parents to offspring F.  having two different alleles for a particular trait genotype recessive phenotype dominant © Edgenuity, Inc. G. describes the allele that when present, masks the appearance of the recessive allele H. describes the allele that is masked when the dominant allele is present I. the physical appearance or characteristics seen in an organism 1 Warm-Up Introduction to Heredity DNA DNA is found in the of cells. DNA stores an organism’s code. DNA is wrapped around and condensed into chromosomes. Genes are used as a set of instructions to produce proteins. Proteins affect the © Edgenuity, Inc. and function of organisms. 2 Instruction Introduction to Heredity Slide 2 Heredity and Genetics Heredity is the passing of traits from to. Genetics is the study of heredity. is known as the “Father of Genetics.” Pea Plant Traits Mendel noticed that peas had many different Seed color Seed shape Pod color Green or yellow Pod shape Yellow or green or round © Edgenuity, Inc.. or bumpy 3 Instruction Introduction to Heredity Slide 2 Pea Plant Traits Mendel noticed that peas had many different characteristics. 4 Plant Flower color Flower Tall or short Purple or Middle or top of stem Pea Plants Experiments Gregor Mendel mated plants with the He took them with he wanted to study. (male reproductive cells) from one plant and joined (female reproductive cells) from a different plant. Example: Green pea x yellow pea Circle one male reproductive structure in the following diagram. © Edgenuity, Inc. 4 Instruction Introduction to Heredity Slide 4 Results of Mendel’s Experiment Parents Parents First-generation offspring First-generation offspring Mendel determined that if he crossed plants with the same characteristics—for example, the same colored peas—the the same characteristics as well. had Results of Mendel’s Experiment offspring First-generation offspring He allowed the Second-generation offspring from anther of one plant to fall on the of the same plant. © Edgenuity, Inc. 5 Instruction Introduction to Heredity Slide 7 Mendel’s Factors Based on his results, Mendel hypothesized that there were things, which he called “ ,” in pea plants that allowed the plants to Parents traits. First-generation offspring offspring First-generation offspring Alleles Alleles are the different forms of a for a given. The gene for seed color has forms. An allele that codes for yellow. An allele that codes for green seeds. © Edgenuity, Inc. 6 Circle the allele that codes for green seeds. Instruction Introduction to Heredity Slide 7 Inheritance of Traits Characteristics that are coded for by genes, traits, can be inherited. One allele for every gene in an is inherited from each. When each parent provides a different allele of a gene, the offspring is for that particular trait. When both parents provide the same allele of a gene, the offspring is for that trait. 9 Characteristics That Are Not Inherited Characteristics that are developed due to factors in the cannot be inherited. Knowledge gained through Muscles developed through exercise © Edgenuity, Inc. learned through practice 7 Instruction Introduction to Heredity Slide 12 Dominant and Recessive A dominant allele is an allele that when present, the appearance of the recessive Circle the recessive allele in the following diagram. allele. A recessive allele is an allele that is masked when the dominant allele is. Dominant and Recessive Traits Trait Dominant Recessive Seed color Yellow Green Seed Round Wrinkled Pod Green Yellow Smooth Bumpy Pod shape Short Plant height Flower color Flower © Edgenuity, Inc. Purple White Middle of stem Top of stem 8 Instruction Introduction to Heredity Slide 14 Genotype Genotype is an organism’s combination. Capital letter for the allele Lowercase letter for the recessive allele Circle the gene for seed color with a recessive allele. Phenotype Phenotype is the physical appearance or organism. seen in an Circle the seed with both recessive alleles in the diagram. © Edgenuity, Inc. Genotype: YY Genotype: Yy Genotype: yy Phenotype: yellow Phenotype: yellow Phenotype: green 9 Summary ? Introduction to Heredity Lesson Question How are traits passed from one generation to the next? Answer Slide 2 Review: Key Concepts Gregor Mendel, the Father of Genetics, used pea plants to study heredity. There are organism. in organisms that affect the traits of the These factors are passed from parent to offspring. One factor is contributed by one parent, and the other factor is contributed by the other parent. The combination of these factors affects how a © Edgenuity, Inc. 10 is observed. Summary Introduction to Heredity Slide 2 Review: Key Concepts Traits are passed from one generation to the next when the material of the parents is combined. for a trait to the offspring. Each parent contributes one Alleles can either be dominant or recessive. A dominant allele is an allele that when present, masks the appearance of the recessive allele. A allele is an allele that is masked when the dominant allele is present. The genetic makeup of an organism affects its characteristics. Genotype is an organism’s allele combination. is the physical appearance or characteristics seen in an organism. © Edgenuity, Inc. 11 Summary Introduction to Heredity Use this space to write any questions or thoughts about this lesson. © Edgenuity, Inc. 12