LESSON CHAPTER 5

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 3

Welcome back 

some refreshing 

Normal body cell: 46 chromosomes

Organised in 23 homologous pairs. 

Each pair has two matching chromosomes. 

How can you tell this is a male karyotype? 

Blue eyes

1. genotype
2. phenotype

Having a facelift

1. genotype
2. phenotype

Mitosis vs Meiosis

How many chromosomes does Chamaecrista fasciculata have?

(see picture)

1. 8
2. 3
3. 16
4. 20

How many chromosomes does an hair cell of a horse have?

1. 30
2. 64
3. 32
4. 31

How many chromosomes does an egg cell of a donkey have?

1. 46
2. 30
3. 62
4. 31

To inherit = to receive a characteristic from an ancestor by genetic transmission. 

• Genotype = complete set of all inherited characteristics. 
• Homozygous dominant, homozygous recessive & heterozygous

• Phenotype = set of characteristics that are seen/expressed. 
• So; this person does have hemophilia and this person doesn't.

Phenotype = genotype + pattern of gene expression + environmental factors. 

Oliver says: 'all humans have the same genes, but not the same alleles'. Charley says: 'all humans have the same alleles, but not the same genes'. Who is right?

1. Oliver
2. Charley
3. They both are
4. They are both wrong

The molecule
shown in the
picture is called ...

1. DNA
2. RNA
3. an amino acid
4. a ribosome

The building blocks for proteins are called ...

1. DNA
2. RNA
3. Amino acids
4. Ribosomes

Allele = a variation of 

a gene. 

So the gene for

hemoglobin (Hb) has

two alleles:

HbA 

HbS

Alleles =

DO YOU REMEMBER?

Is it a gene or an allele?

GENE

ALLELE

skin colour

curly hair

flower colour

blue eyes

blood type

type A blood

colour-blindness

hair type

short wings in a fruit fly

DO YOU REMEMBER?

mutations 

mutations

= change in a gene or chromosome (genotype)

This may result in no/small/large change in phenotype

the change can be negative/neutral/beneficial

Autosomes

Autosomes

'Normal' genes

AA - Aa - aa

Sex chromosomes

Sex-linked genes

XHXH - XHXh - XhXh 

XHY - XhY

TIP TO STUDY: 

• Make sure you recognize & know the terms (for example by using flashcards)
  
• PRACTISE PRACTISE PRACTISE. Do the exercises (again)
• Ask questions when you are struggling to solve one of the questions or do not understand why a certain answer is right. 
• Watch the Youtube videos that we have watched in class again! Stated Cleary & Amoeba sisters! 

time to work 

study basics 1 to 5 

do the exc.