3t chapter 7.4 monohybrid crosses

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Slide 1: Slide
BiologieMiddelbare schoolvwoLeerjaar 3

This lesson contains 41 slides, with interactive quizzes and text slides.

Items in this lesson

Slide 1 - Slide

Exercise 1
A father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.

a. Is mother homozygous or heterozygous for eye colour?
   
   b. Two children are born. Child 1 has brown eyes and child 2 has blue eyes. Show this in a cross. Use the letters B and b

Slide 2 - Slide

P
P
genotype
phenotype
F1
sex cells
possibilities for F1:

Slide 3 - Slide

Father has brown eyes. 

Slide 4 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
possibilities for F1:

Slide 5 - Slide

Mother has blue eyes. 

Slide 6 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
blue eyes
possibilities for F1:

Slide 7 - Slide

A father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.


Slide 8 - Slide

Slide 9 - Slide

gene is eye colour

2 alleles, they can be:
  • brown - brown = homozygous
  • blue - blue       = homozygous
  • brown - blue    = heterozygous


brown is dominant: B
blue is recessive:   b


  • brown - brown: notation =  BB
  • blue - blue:       notation =  bb
  • brown - blue:    notation =  Bb
B
b

Slide 10 - Slide

What means homozygous?
A
a chromosome pair with two equal alleles: AA and aa
B
a chromosome pair with two equal alleles: Aa
C
a chromosome pair with two different alleles: AA and aa
D
a chromosome pair with two different alleles: Aa

Slide 11 - Quiz

What means heterozygous?
A
a chromosome pair with two equal alleles: AA and aa
B
a chromosome pair with two equal alleles: Aa
C
a chromosome pair with two different alleles: Aa
D
a chromosome pair with two different alleles: AA and aa

Slide 12 - Quiz

A father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.

How do you notate the genotypes of father and mother?


Slide 13 - Slide

Father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.

How do you notate the genotypes of father and mother?
A
father BB, mother Bb
B
father Bb, mother BB
C
father BB, mother bb
D
father Bb, mother bb

Slide 14 - Quiz

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
blue eyes
bb                             Bb
possibilities for F1:

Slide 15 - Slide

A father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.

a. Is mother homozygous or heterozygous for eye colour?
  

Slide 16 - Slide

Is mother homozygous or heterozygous for eye colour?
A
homozygous
B
heterozygous

Slide 17 - Quiz

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
blue eyes
bb                             Bb
possibilities for F1:
And now the sex cells are made...

Slide 18 - Slide

Sex cells are made by meiosis.
What happens during meiosis?
One answer is NOT correct. Which one?
A
a diploid (2n) cell divides into 4 haploid (n) cells
B
chromosome pairs are pulled apart into different cells
C
a diploid (2n) cell divides into 2 diploid cells (2n)
D
After meiosis there are 4 sperm cells and 2 egg cells made.

Slide 19 - Quiz

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:

Slide 20 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:
What eye colour do the children (F1) have?

Slide 21 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
b
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:
spermcells 
egg cells

Slide 22 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
b
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:

Slide 23 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
bb
b
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:

Slide 24 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
bb
b
Bb
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:

Slide 25 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
bb
b
Bb
bb
brown eyes
blue eyes
bb                             Bb
b
b
b
B
possibilities for F1:

Slide 26 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
bb
b
Bb
bb
brown eyes
blue eyes
bb                             Bb
b
b
b
B
genotype        
  • 2x Bb (50%) 
  • 2x bb (50%) 
possibilities for F1:

Slide 27 - Slide

P
P
genotype:
phenotype:
F1
sex cells:
B
b
b
Bb
bb
b
Bb
bb
brown eyes
blue eyes
bb                             Bb
b
b
b
B
genotype        
  • 2x Bb (50%) 
  • 2x bb (50%) 
phenotype
  • brown eyes
  • blue eyes
possibilities for F1:

Slide 28 - Slide

Exercise 1
A father has brown eyes. He is heterozygous for eye colour. Mother has blue eyes. The gene for brown eyes is dominant.
a. Is mother homozygous or heterozygous for eye colour?
Mother is homozygous : she has bb
   b. Two children are born. Child 1 has brown eyes and child 2 has blue eyes. Show this in a cross. Use the letters B and b
Done.

Slide 29 - Slide

P
P
genotype
phenotype
F1
sex cells
possibilities for F1:

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