Transcript 4/20 & 4/21 - 7th Grade Agenda
12/20 & 12/21 - 7 th Grade Agenda
Learning Objective: Learn about Punnett Squares
Collect HW: Reading & Note Taking p. 89 – 92
BrainPop Genetics, Heredity & Genetic Mutations
Video: Test your Brain
HW: Science Fair Background due 1/17 & 1/18 (10 Points)
Reflection
• Prompt: Complete the following Punnette Square
Tt T t Tt T t
Reflection
• Prompt: Complete the following Punnette Square
Tt T t Tt T TT Tt t Tt tt
Mendel’s Experiment
• • What would happen if you cross pollinate a tall plant with short plant?
Why?
What is a allele?
• One part of a gene pair. Alleles represent different varieties of one trait such as height of pea plant.
• Two alleles form a gene pair
What is a Dominant Allele?
• • One whose trait always shows up in the organism when the allele is present Dominant allele is represented by a
CAPITAL
letter
What is a Recessive Allele?
• • A recessive allele is always covered up or masked whenever the dominant allele is present Recessive allele is represented by a
lowercase
letter
Phenotype Genotype TT X tt Tt X Tt TT Tt Tt tt
What are Genotype & Phenotype?
• Phenotype: Physical appearance • Genotype: Genetic makeup
Punnette Squares
Practice Creating Punnett Squares BB B B Bb bb b Bb b Bb Bb
Practice Creating Punnett Squares Bb B b Bb Bb B BB b Bb bb
Practice Creating Punnett Squares Bb B b bb bb b Bb b Bb bb
Practice Creating Punnett Squares GG G G Gg gg g Gg Gg Gg g
What is Codominance?
• The alleles are neither dominant nor recessive
What is incomplete dominance?
• Both alleles are blended in the offspring
Human chromosomes
• Each human body cell contain 23 chromosomes • • chromosomes.
There are 35,000 genes in the chromosomes in the same order on both chromosomes
Meiosis
• Meiosis is the process by which the number of chromosomes is reduced by
alf rm
eggs.
Meiosis Meiosis I Meiosis II