2.17 Punnett Square Day 1

12/8 and 12/9 2014

Do Now• What is a gene?• What do genes have the instructions for?• How many proteins are made out of 1 gene?• What is a chromosome?• How many chromosomes did you get from your

mom?• How many chromosomes did you get from your dad?• How many chromosomes do you have in total?• How many copies of each chromosome do you have?

2.17 Punnett Squares Day 1

Learning Skills Target

Standard

HW

Agenda

2.8 I can model the way humans and plants use sexual reproduction to produce offspring with genetic variation

MS-LS3-2 Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation

Due Thursday/Friday 12/11 and 12/12 2014:2.17 Gorlox Genetics2.17 Punnett Practice: Videos on Versal2.17 Spongebob Genetics 12.17 Punnett Mind MapEnrichment work. For students who finished all their previous missing assignments2.17 Gorlox Genetics: F1 Generation2.17 Spongebob Gnetics 2

Do Now, Daily Mission, Alleles Notes, Agenda

Essential question:How can parents with brown hair have a child with blonde hair?

Quick Genetics Review• Genetics is the study of heredity• Heredity is how traits are passed down from parent to offspring.• Traits are characteristics of an offspring, like color or nose shape• Genes are small sections of chromosomes that are responsible

for your traits (height, hair color etc.)– Each gene codes for a protein

What is a trait• Trait: A notable feature or quality in a person. • Each of us has a different combination of traits that

make us unique• Traits determined by your genes and are passed

down from generation to generation– We inherit traits from our parents and pass them down

to our children.

Essential questions:

1. How can parents with brown hair have a child with blonde hair?

What is Heredity:• Heredity is the passing down and inheritance of

genes and traits.– Inheritance means receiving/getting from your parents– Heredity is the passing down and getting of genes from

parent to child

The parents carry the recessive gene for blue eyes. Most children received at least one dominant brown eyed gene. One child received both recessive blue eyed genes and therefore, 1 child has blue eyes.

What is an allele • Alleles: The different forms of a gene• You have 2 alleles for each gene, one

on each homologous chromosome– Homologous chromosome =

chromosome of the same number– Chromosomes 1 through 23. You have

2 of each number from your parents– You get one of each homologous

chromosome from each parent• Alleles are represented by a letter• For each gene, you receive on allele

from your mom and another allele from your dad.

• Together, your alleles determine your traits

Review: Chromosomes and Genes

• Let’s say the gene for eye color is on chromosome 1 wit the allele P

• You have two copies of each homologous chromosome, one from each parent.

• This means you have two copies of each gene.

• You have two copies of each allele

Chromosome 1 Chromosome 1

How many alleles do you have for each gene?

• You have 2 alleles for each gene because you have 2 copies of each gene. Each chromosome has its own allele.

• You get 1 allele from your mom and 1 allele from your dad

Chromosome 1 Chromosome 1

What is a genotype?

• Genotype: The allele combination of your genes.

• There are 2 alleles for each gene • Genotype is written with 2 letters

What does homozygous mean?

• Homozygous: The same 2 alleles in the genotype for a single gene

• Homozygous dominant genotype for straight thumb is HH

• Homozygous Recessive genotype for hitchhiker’s thumb is hh

What do you think happens if the alleles are different?

H + h?????

What is Dominant Allele

• Dominant Allele: The allele that is strong and dominant. It will mask (hide) the weak allele in an organism with a mixture of alleles

• The dominant allele is represented by a capital letter.

What is a recessive Allele

• Recessive Allele: The weak allele that can only be seen when the organism is homozygous recessive (both alleles are recessive).

• The weak allele gets hidden by the dominant allele.

What do you think happens if the alleles are different?

H + h?????

Or

What does Heterozygous mean?• Heterozygous: When

the 2 alleles of a gene are different.

• The dominant allele is expressed (shown).

• The organism has the dominant allele trait

• The recessive allele remains hidden. It is still in the DNA, but you can’t see it.

What is the difference between a gene and a trait?

What is a Phenotype

• Phenotype: The way an organism looks because of their genes. The way the gene is expressed.

• The phenotype is based on the genotype.• Homozygous dominant DD and heterozygous dominant

Dd have different Genotypes, but the same phenotype dominant phenotype, or look.

Genotype Vs Phenotype

Stations