Transcript Whose got Genes?

Tuesday, January 19, 2016 Day 1
Day 2
1. Please have these
Items on your desk.
Agenda
Notebook
Science
Starters
Sheet
2- Science Starter:
What does heterozygous dominant mean?
Give an example.
If a trait is recessive, is it heterozygous or
Homozygous?
To do list. . . . .
Update the goal sheet. Pick four
assignments or notes and update the goal
sheet.
Finish notes on Punnett square.
Practice making Punnett squares.
Table of Contents Update
Page 85
1/15
Genes, Heredity &
DNA
Baker 2003/2004
Whose got Genes? Part 2
Genes, Heredity, & DNA
Baker 2003/2004
Who was Gregor Mendel?
Austrian monk who studied
mathematics and science
As a boy he could predict the
possible types of flowers and
fruits that would result from
crossbreeding two plants in his
father’s garden
Picture taken from biography.com
Baker 2003/2004
Who was Gregor Mendel?
Curiosity about the connection
between the color of a pea flower
and the type of seed that same
plant produced inspired him to begin
experimenting with garden peas in
1856.
Made careful use of scientific
methods, which resulted in the first
recorded study of how traits pass
from one generation to the next.
Baker 2003/2004
Define HEREDITY
The passing of traits
from parent to
offspring
Baker 2003/2004
Define ALLELE
The different forms of a
trait that a gene may
have
One form of a gene
Baker 2003/2004
What is HOMOZYGOUS?
AA
aa
Both alleles [forms of the gene]
are the same
When offspring inherit two
dominant genes, (one dominant
gene from each parent) they are
said to be homozygous dominant
When offspring inherit two
recessive genes, (one recessive
gene from each parent) they are
said to be homozygous recessive
Baker 2003/2004
What is
HETEROZYGOUS?
Aa
When alleles occur in
different forms
When offspring inherit one
dominant gene and one
recessive gene, they are said
to be heterozygous
Since the dominant gene will
be expressed, they are said to
be heterozygous dominant
Baker 2003/2004
Generation 1
B
B
b
b
B Brown Eyes are
Dominant to b Blue Eyes
b
b b
Heterozygous
Homozygous
recessive
Genotype
b
B b
2 Bb 2bb
b b
Phenotype
50% Brown
50% Blue
Baker 2003/2004
Generation 2
B Brown Eyes are
Dominant to b Blue Eyes
B
b
B
B b
B
b
Homozygous
Dominant
Homozygous
Recessive
Genotype
b
B
b
B
b
4 Bb
Phenotype
100% Brown Eyes
Baker 2003/2004
Generation 3
B Brown Eyes are Dominant
to b Blue Eyes
B
B
B B
B
B B
Homozygous
Dominant
Heterozygous
Genotype
b
B b
B b
2 BB 2 Bb
Phenotype
Baker 2003/2004
100% Brown
Eyes