Content Objectives Write these down!

Transcription

1 Content Objectives Write these down! I will be able to identify: Key terms associated with Mendelian Genetics The patterns of heredity explained by Mendel The law of segregation The relationship between GENOTYPE and PHENOTYPE

2 Language Objectives Write these down! I will complete a graphic organizer in key terms associated with Mendel s work on Heredity defining terms in my own words I will discuss and record important ideas, facts, and concepts about heredity using Cornell Notes. I will read and discuss with my group a short passage on Mendel s Theory.

3 Chapter 12 Section 2: Mendel s Theory Key Vocabulary Terms Adapted from Holt Biology 2008

4 Mendelian theory of heredity Mendelian theory explains simple patterns of inheritance. In these patterns, two of several versions of a gene combine and result in one of several possible traits.

5 1. One of two or more alternative forms of a gene, each leading to a unique trait. Symbolized with a single letter. 2. One member of a pair or series of genes that occupy a specific position on a specific chromosome. Allele

6 Dominant Describes an allele that is fully expressed whenever the allele is present in an individual. Use a capital letter.

7 Recessive Describes an allele that is expressed only when there is no dominant allele present in an individual Use a lower case letter.

8 Genotype A specific combination of alleles in an individual (two or more letters to show which alleles are present). The genetic constitution of a cell, an organism, or an individual (i.e. the specific allele makeup of the individual).

9 Phenotype genotype determines phenotype The detectable trait or traits that result from the genotype of an individual (words that describe a trait). The appearance of an organism resulting from the interaction of the genotype and the environment.

10 Homozygous Describes an individual that has two identical alleles. Having identical pairs of genes for any given pair of hereditary characteristics.

11 Heterozygous Describes an individual that has two different alleles Having different alleles at one or more corresponding chromosomal loci.

12 When an organism produces gametes, each pair of alleles is separated and each gamete has an equal chance of receiving either one of the alleles. Law of segregation

13 Dihybrid cross Cross between F1 offspring of two individuals that differ in two traits of particular interest.

14 Linked genes Two or more genes that are inherited together found on the same Chromosome (red hair and freckles)

15 Content Objectives Write these down! I will be able to identify: define and use in a sentence, Key Terms associated with Mendel s Theory of heredity. The patterns of heredity explained by Mendel And explain The law of Segregation The relationship between GENOTYPE and PHENOTYPE

16 Language Objectives Write these down! I will complete a graphic organizer in key terms associated with Mendel s work on Heredity defining terms in my own words I will discuss and record important ideas, facts, and concepts about heredity using Cornell Notes. I will read and discuss with my group a short passage on Mendel s Theory.

17 Vocabulary List Use in a Sentence! Allele Dominant Recessive Genotype Phenotype Homozygous Heterozygous Law of segregation Dihybrid cross Linked genes

18 Chapter 12 Section 2: Mendel s Theory Notes Adapted from Holt Biology 2008

19 Mendel s Conclusions for the 7 characters in pea plants 1. Each parent contributes one factor (allele) per trait in the offspring.

20 Mendel s Conclusions for the 7 characters in pea plants 2. The factors (alleles) separate randomly when gametes form. (Law of segregation)

21 Mendel s Conclusions for the 7 characters in pea plants 3. A dominant allele is expressed when one or two of the dominant alleles is inherited.

22 Mendel s Conclusions for the 7 characters in pea plants 4. A recessive allele is only expressed if both of the inherited alleles are recessive.

23 Mendel s codes for alleles are still used today. Capital letters for the dominant allele Lower case letters for the recessive allele. The letter for the character is the letter of the dominant trait.

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25 12-2 Mendel s Theory Genotypes: PP Pp pp Homozygous X X Heterozygous X Phenotypes: Purple Purple White Why does the Pp genotype have a purple phenotype?

26 Mendel s Second Experiments Dihybrid cross: initial parents had TWO contrasting characters (traits).

27 Mendel s Dihybrid Cross Conclusion Law of Independent Assortment During gamete formation (meiosis), the alleles of each gene segregate independently. The alleles for seed color and seed shape can randomly mix and match.

28 Genes on Chromosomes We now know that genes that are on the same chromosome are inherited together (linked). Linked genes do NOT follow the Law of Independent Assortment