U5 B3 2HVTTO

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 2

B3 Genes and alleles

• Take off your jacket
• Put your things on your desk

       Book, notebook, pencil case

• Bag on the floor
  
• Read pages 116-118

Lessongoals

• You can describe what genes and alleles are.
• You can describe what a mutation is
• You can describe what cancer is

Wheel of homework

Go to Lessonup.app and use this code

Reward

Penalty

What is the difference between genotype and phenotype?

1. genotype is the information fenotype is how you look/work
2. phenotype is the information genotype is how you look/work
3. They are nearly the same thing

What genes are found in the cells of your liver?

1. all genes used by the liver, once
2. all genes used by the liver, twice
3. all genes found in humans, once
4. all genes found in humans, twice

What genes are found in a sperm cell?

1. All genes used by the sperm, once
2. All genes used by the sperm, twice
3. All genes found in humans, once
4. All genes found in humans, twice

A human ovum contains ... pairs of chromosomes. (number)

DNA, how it's built

Basepair

Combination of A-T or C-G. Other combinations are impossible in the DNA

Gene

Many (often thousands) of basepairs together contain the information of a gene. The order of the basepairs decides the code and its contents.

Base

Buildingblock of the DNA, there's 4 types:

• A (adenine)
• C (cytosine)
• T (thymine)
• G (guanine)

Genes and characteristics

• 1 characteristic often is made up of different genes
• Genes contain information to make proteins
• Sometimes parts of a gene are on different chromosomes

Alleles

Genes have different gene variants: alleles

Alleles (variants) of eyecolor: blue, brown, green, etc.

Some alleles are stronger than others

Allele pairs

Alleles of 1 gene form pairs:

• 2 same alleles = homozygous
• 2 different alleles = heterozygous

Which is an allele that has to do with hair?

1. Hair colour
2. Blond
3. Hair schape
4. Blue

Which cells contain alleles for hair colour?
Pick the answer showing the most correct cells

1. Hair cells
2. Hair and head cells
3. Hair, head and brain cells
4. Hair, head, brain and eye cells

Which allels could you both find in the same sperm cell?

1. Brown hair Blond hair
2. Blue eyes Green eyes
3. Brown hair Blue eyes
4. Red hair Blond hair

What you should do:

• Read pages  116-120
• Do asgmt  1-8, 4choice pgs. 120-123
• Challenge: 9 and 10 pgs. 123-124 

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zs = Working in Silence

• No asking questions
• Silent, don't disturb anyone
  
• Stay at your  desk

What you should do:

• Read pages 116-120
  
• Do asgmt 1-8, 4choice pgs. 120-123
  
• Challenge: 9 and 10 pgs. 123-124

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zw = Working with whispering

• Teacher is available for questions
• Only whisper with the student next to you
• Stay at your  desk

Sexual reproduction

• Sperm/ova are made during meiosis.
• This creates sex cells with many different alleles.
• During fertilization a new genotype is formed. This contains alleles of both mother and father

A man and woman have a baby.
The man is homozygous for blond hair.
The woman is homozygous for brown hair.
Explain, will the baby be homzygous or heterozygous for hair colour?

Mutations

• The genotyp of a person can not change
• Mutation = part of the DNA (in a cell) changes
• Usually little to no influence
• Organism where mutation shows in phenotype = mutant
• The moment and place of mutation are important

How does DNA mutate?

Mutations can be caused by mutagenic influences:

• Sunlight (UV-radiation)
• Radioactive radiation (Röntgen)
• Asbestos, smoke

Mutations also happen by mistake during cell division

Cancer, how and why?

• Happens due to mutations, Not bacteria/virus
• Mutation makes cells divide continously      
• this creates a tumour:

       - Benign: Divides slowly, stays at its spot

       - Malignant: divides quickly, disrupts tissues

• Metastasis > cancer cells are carried by blood/lymph. End up in different body parts and create more/new tumours

What you should do:

• Read pages  116-120
• Do asgmt  1-8, 4choice pgs. 120-123
• Challenge: 9 and 10 pgs. 123-124 

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zs = Working in Silence

• No asking questions
• Silent, don't disturb anyone
  
• Stay at your  desk

What you should do:

• Read pages 116-120
  
• Do asgmt 1-8, 4choice pgs. 120-123
  
• Challenge: 9 and 10 pgs. 123-124

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zw = Working with whispering

• Teacher is available for questions
• Only whisper with the student next to you
• Stay at your  desk

Tidy Duty

Today these people are on tidy duty

• Desks: empty and straight
• Chairs:  underneath the desks
• Floor: no rubbish