Recap basic 1 - 3 genetics V3 2425

• Biologie
• Middelbare school
• vwo
• Leerjaar 3

Welcome!

• Recap basic 1 - 3 unit 5

Basic 1 genotype and phenotype

• I can describe what the genotype and phenotype are.
  

Concepts: nucleus, chromosomes, DNA, inherited characteristics, gene, genotype, phenotype.

• I can explain that cells only use the hereditary information that they need.
  

Concepts: genes, activation.

1. What is the difference between your genotype and your phenotype.
2. Give an example of your genotype and phenotype

Genotype

Phenotype

Risk for a genetic disease

Phenotype = genotype + environmental influences

The phenotype changes…

…but the genotype doesn’t.

Put the following in order of size

Smallest                                                                         Biggest

gene

Chromosome

Nucleus

cell

What is what?

• DNA  = substance that contains information for hereditary characteristics
• Gene = the pieces of DNA that together contain the information for a hereditary characteristic
• Chromosome = a long, thin thread in the cell nucleus
• Cell = building block of an organism

In this question we will compare a liver cell and a muscle cell of 1 person
A. Is the genotype of the liver cell and muscle cell the same?
B. Can you find the same substances in the two cells?
C. Are all genes activated in the two different cells?

Gene activation

Basic 2 Chromosomes 

• I can explain how each of the parent supplies 50% of the chromosomes.
  

Concepts: body cells, sex cells, chromosome pair, gene variant (allele)

• I can say how the sex of humans is determined by sex chromosomes.
  

Concepts: female (XX), male (XY), intersex (XXY)

• I can explain how sexual reproduction causes variation in genotypes.
  

Concepts: sex cells, meiosis, daughter cells, sexual reproduction, variation in genotypes

Drag the number of chromosomes to the correct place

46 chromosomes

46 chromosomes

46 chromosomes

  23 chromosomes

23 chromosomes

A human cell has 23 chromosomes, so it must be a...

1. Body cell
2. Sex cell

A cell of a random organism has 7 chromosomes, this must be a...

1. Sex cell
2. Body cell

Sexual reproduction 50% DNA of each parent 

Karyogram picture set of chromosomes

• Chromosomes comes in pairs in body cells
• Sex chromosomes determine your sex
• XX = female
  XY = male

This is a karytype of.

1. sperm cell
2. egg cell
3. body cell
4. you can't tell

In the picture on the right are two cells of a plant drawn. Use the picture to answer the following questions:
1. How many chromosomes pairs does the plant have?
2. Which of the two cells is a sex cell, explain your answer.
3. How many chromosomes does the plant has in total?

What is genetic varation?

Genetic variation caused by sexual reproduction

Basic 3 genes and alleles 

• I can describe what genes and alleles are.
  

Concepts: DNA, base pairs, genes, alleles, allele pair, proteins

• I can describe what a mutation is.
  

Concepts: mutation, mutant, mutagenic influences

• I can describe what cancer is.
  

Concepts: cancer, metastasis, cell division

Gene versus Allele 

Name the gene that belongs to the following traits:
1. Blue eyes
2. Brown eyes
3. Curly hair
4. Straight hair
5. Dark skin

2. Give the alleles for the following traits (tip: look at your classmates):
1. Hair texture
2. Hair colour
3. Eye colour
4. hight

Alleles

• Chromosomes come in pairs
• So for each genes you have two copies
• an alle is a variant of a gene
• You can have the same or two different alleles for a gene 

What happens if there is a change in the DNA sequence?

1. You die
2. You will be a superhero
3. Nothing happens
4. You get a new trait

Mutation: change in DNA sequence

Mutations are caused by mutagenic influences.
Can you give three examples of mutagenic influences?

Mutagenic influences

• All cause mutations, change in DNA sequences
• Are mutations bad, neutral or good?  

How cancer arises