content objectives write these down!...mendel’s theory notes . mendel’s conclusions for the 7...
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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
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.
Adapted from Holt Biology 2008
Chapter 12 Section 2: Mendel’s Theory
Key Vocabulary Terms
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.
Allele 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.
Dominant
Describes an allele that is fully expressed whenever the allele is present in an individual.
Use a capital letter.
Recessive
Describes an allele that is expressed only when there is no dominant allele present in an
individual
Use a lower case letter.
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).
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.
Homozygous
Describes an individual that has two identical alleles.
Having identical pairs of genes for any given pair of hereditary characteristics.
Heterozygous
Describes an individual that has two different alleles
Having different alleles at one or more corresponding chromosomal loci.
Law of segregation
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.
Dihybrid cross
Cross between F1 offspring of two individuals that differ in two traits of
particular interest.
Linked genes
Two or more genes that are inherited together
found on the same Chromosome
(red hair and freckles)
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
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.
Vocabulary List Use in a Sentence!
• Allele
• Dominant
• Recessive
• Genotype
• Phenotype
• Homozygous
• Heterozygous
• Law of segregation
• Dihybrid cross
• Linked genes
Adapted from Holt Biology 2008
Chapter 12 Section 2:
Mendel’s Theory
Notes
Mendel’s Conclusions for the 7 characters in pea plants
1. Each parent contributes one factor (allele) per trait in the offspring.
Mendel’s Conclusions for the 7 characters in pea plants
2. The factors (alleles) separate randomly when gametes form. (Law of segregation)
3. A dominant allele is expressed when one or two of the dominant alleles is inherited.
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.
Mendel’s Conclusions for the 7 characters in pea plants
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.
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?
Mendel’s Second Experiments
Dihybrid cross: initial parents
had TWO contrasting characters
(traits).
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.
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