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: Diapositive
BiologieMiddelbare schoolvwoLeerjaar 3

Cette leçon contient 10 diapositives, avec quiz interactif, diapositives de texte et 1 vidéo.

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5.6 the difference of being a boy or girl

Slide 1 - Diapositive

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

Slide 2 - Question ouverte

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

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

Slide 3 - Diapositive

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

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

Slide 4 - Diapositive

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 - Diapositive

Slide 6 - Vidéo

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 - Diapositive

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 - Diapositive

LET'S PRACTISE TOGETHER

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 - Diapositive

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

Slide 10 - Diapositive