You and your genes Flashcards
Where are chromosomes found?
In the nucleus of most cells
Where is DNA found?
In chromosomes
What is a gene?
A section of DNA with the genetic code for making a particular protein
Where are structural proteins found?
In muscles/hair
What are the two proteins that genes are responsible for making?
Structural proteins & enzymes
How many pairs of chromosomes does each human body cell contain?
23
How do parents pass their genes onto their offspring?
Through their sex cells
What are the different versions of a gene called?
Alleles
Do sex cells contain 1 or 2 chromosomes?
1
When an egg and sperm cell join together, how many chromosomes does the fertilized egg contain?
23, one chromosome from each pair comes from the mother, one from the father (which we get is random)
Which gender receives XX chromosomes?
Females
Which gender receives XY chromosomes?
Males
What determines the gender of a human baby?
Whether the sperm carries an X or Y chromosone
How can people of some societies CHOOSE the gender of their child?
Through IVF fertility treatment
What are the ethical issues with choosing the gender of your child?
Effects the balance of genders in society/some think we shouldn’t be able to choose
What are the ethical issues with choosing the gender of your child?
Effects the balance of genders in society/some believe is is against God or nature
What does SRY stand for?
Sex-determining Region Y
What does the SRY gene do?
Causes testes to develop into an XY embryo
What are androgens?
Male sex hormones (without these, the embryo develops into a female)
What does the term ‘variation’ refer to?
The difference in individuals of the same species
What factors does genetic variation affect?
Eye colour/height etc
What factors does environmental variation affect?
Scars/climate etc
What is a recessive allele?
Shows is an individual has two copies of it, eg the allele for blue eyes (you need both copies)
What is a dominant allele?
Always shows even if the individual only has one copy, eg the allele for brown eyes (you only need one copy)
What is an example ‘carrier’?
Someone with a gene for both brown and blue eyes could still pass down the blue eye gene, even though they have the dominant brown eye gene
What kind of allele causes Cystic Fibrosis?
Recessive
What are the symptoms of Cystic Fibrosis?
Thick, sticky mucus in their lungs and airways
What kind of allele causes Huntington’s disorder?
Dominant
What are the symptoms of Huntington’s disorder?
Problems with controlling your muscles/forgetfulness
What is an example of a ‘carrier’?
Someone with a gene for both brown and blue eyes could still pass down the blue eye gene, even though they have the dominant brown eye gene
