5.6 the difference of being a boy or girl

5.6 the difference of being a boy or girl
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Slide 1: Slide
BiologieMiddelbare schoolvwoLeerjaar 3

This lesson contains 10 slides, with interactive quiz, text slides and 1 video.

Items in this lesson

5.6 the difference of being a boy or girl

Slide 1 - Slide

what is:
1. an allele
2. dominant allele
3. recessive allele

Slide 2 - Open question

male and female
male:    2x 22 autosomes + X + Y = 46 chromosomes

female: 2x 22 autosomes + X + X = 46 chromosomes

Slide 3 - Slide

egg cell and sperm cell
egg cell contains 22 autosomes + X chromsome

sperm cell contains 22 autosomes + X or 22 autosomes + Y

Slide 4 - Slide

today''s program 
learning objectives: you're able to answer the following questions

  • why do certain inherited diseases occur more often in boys than in girls?

  • given a certain combination of parents, how can you determine the genotype and phenotype of sex-linked inherited characteristics in the offspring? 

Slide 5 - Slide

Slide 6 - Video

recap - sex linked traits
female: XX,  male: XY
traits are only on the X chromosome
On the Y is just all the genes for becoming a man
Genotypes are written down like this (when they are sex linked!) XHXh or XhXh

Slide 7 - Slide

calculating chances
1. write down both genotypes XX and XY with the trait XHXH and XhY for example
2. Use a punnet square!
3. Calculate the chance of every possible phenotype and answer the question

Slide 8 - Slide


A mother who is a carrier for colour-blindness gets a child with a father who has normal vision. 

What are the probabilities of their children being colour-blind? Use a Punnet square! 
colour-blindness is sex-linked!

Slide 9 - Slide

start homework!
study 5.6
do excercise 37, 38, 40, 41, 42, 43, 44, 45

Slide 10 - Slide