BS2 - Chromosomes

Chromosomes
Contain DNA

Bundled DNA-fibre wrapped around histones

23 chromosome pairs in humans
1 / 13
volgende
Slide 1: Tekstslide
BiologieMiddelbare schoolvwoLeerjaar 3

In deze les zitten 13 slides, met interactieve quizzen, tekstslides en 1 video.

time-iconLesduur is: 45 min

Onderdelen in deze les

Chromosomes
Contain DNA

Bundled DNA-fibre wrapped around histones

23 chromosome pairs in humans

Slide 1 - Tekstslide

Body cells
The nucleus of the body cells of a human:
(ex. liver cells, skin cells, muscle cells etc) contain 46 chromosomes. 

Every chromosome carries the information for different hereditary traits. 
Chromosomes occur in pairs. 
Two chromosomes in a pair match; they carry information for the same traits. 
There are 23 pairs.



Slide 2 - Tekstslide

Sex cells
Sex cells are different than the body cells.
 
Sex cells contain 23 chromosomes. There are no pairs. 
Ex. Sperm cell and egg cell

Nucleus of the sex cell of a man and the nucleus of the sex cell of a woman fuse together. 

This way the child has 50% of its genetic information form the father and 50% of the mother. 

Pair 23 will determine the sex of the child. This depends of chromosome 23 of the spermcell  is a X or a Y chromosome. 

Slide 3 - Tekstslide

cells and chromosomes
humans have in EACH body cell: 
  • 22 pairs of body cells
  • 1 pair of sex chromosomes : X X = female, XY=male 

so, humans have in EACH gamete (sex cell):
  • 22 body cells
  • 1 sex chromosome


Slide 4 - Tekstslide

Variation in genes
  • Sex cells = no pairs of chromosomes. 
  • only 1 copy of the chromosome ends up in the egg or sperm cell.
  • result: variation in genotypes 

Slide 5 - Tekstslide

Variatie in genotype
  • Due to sexual reproduction.
  • father 1/2 and mother 1/2 contribute 1 copy of chromosome.
  • The part of the chromosome that is give to child from parents is different each time.
  • Chance/coincidence!

Slide 6 - Tekstslide

Slide 7 - Video

Each human being has 46 chromosomes. How many did you get from your mother?
A
46
B
23
C
22
D
45

Slide 8 - Quizvraag

A person containing an XY is a...
A
man
B
woman

Slide 9 - Quizvraag

A person containing the same copy of a sex chromosome is a...
A
man
B
woman

Slide 10 - Quizvraag

You have 23 sex chromosomes in your body.
A
True
B
False

Slide 11 - Quizvraag

Slide 12 - Tekstslide

Write down the sex chromosomes of someone who is intersex.

Slide 13 - Open vraag