B1 - You And Your Genes Flashcards
Where are genes found?
In the nucleus of every cell
What is a gene?
They carry information needed for you to develop
What are chromosomes made up of
DNA molecules. 2 very long strands
What is alleles?
Different versions of a gene
What is homozygous
Where you inherit 2 alleles that are the same
What is heterozygous?
Where you inherit 2 alleles that are different
What is a dominant allele?
Controls the development of a characteristic, even if it’s present on only one chromosome in a pair
What is a recessive allele?
Controls the development of a characteristic, but if this allele is present it must be on both chromosomes in a pair
How many chromosomes in a cell?
46 chromosomes, 23 pairs
What is genotype?
The combination of alleles you have
What is your phenotype?
The actual characteristics you show
What environmental factors can influence characteristics?
Poor diet leads to disease, country can change your language/accent
Why is the Y chromosome called the sex-determining region Y gene?
Because if the Y gene isn’t present (there are 2 X chromosomes) the embryo will develop into a female
What happens when the Y chromosome is present but androgen isn’t present?
The embryo develops female sex organs (excluding the uterus) or the baby has a female body but is infertile
What are symptoms of huntingtons disease?
Involuntary movement, clumsiness, memory loss, mood changes and inability to concentrate
How many parents need to pass on the gene for the child to inherit it and why?
One parent because the allele is dominant
What are the symptoms of cystic fibrosis?
Weight loss, difficulty on breathing, chest infections and difficulty in digesting food
How many alleles does a person need to inherit cystic fibrosis and why?
2 because the allele for cystic fibrosis is recessive
What happens if you inherit one allele for cystic fibrosis?
You become a carrier of the disease but you do not get the symptoms
Why do people disagree with killing someone who has huntingtons disease?
Because people do not develop ye symptoms until later life so they could lead a normal life and also false positives
Where can you test for faulty allele in a fetus?
In the fluid surrounding it
What are the risks of testing fetuses?
Miscarriages
What are the ethical concerns with testing fetuses?
Whether pregnancy termination should be considered and the effects it could have on individuals or relationships
What is a true positive?
The test result says the fetus has the disorder, reality is the fetus has the disorder
What is a true negative?
Where test says fetus doesn’t have the disorder, reality fetus doesn’t have the disorder
What is a false positive?
Where the test result says fetus has the disorder, reality is fetus doesn’t have the disorder
What is a false negative?
Where the test result says fetus doesn’t have the disorder, reality fetus has the disorder
What are the opposing views on genetic testing?
These disorders are natural and should not be eliminated
What is the for view of genetic testing?
Means less suffering
In embryo selection was is the way embryos can be produced?
In vitro fertilisation (IVF)
What is the procedure for embryo selection?
Pre-implantation Genetic Diagnosis (PGD)
What is the procedure for embryo selection?
After fertilisation embryos dived into 8 cells before a single cell is removed from each for testing to see if they have the alleles for a genetic disorder
Why is embryo selection controversial?
Some say it’s unnatural, concerns for selecting certain characteristics (eye colour, sex)
What are the concerns for pre selection?
Reduces variation meaning certain alleles could disappear over time
What is a stem cell?
An unspecialised cell
What can stem cells do?
Replace damage tissues to help patient with disease like Parkinson’s disease
How many types of stem cells are there and what are they?
There are 2, adult and embryonic
Where are adult stem cells taken from?
Taken from areas that are adapted for the replaced and repair of tissues like the umbilical cord blood and bone marrow
What can adult stem cells develop into?
A range of specialised cells but not all types
Where are embryonic stem cells taken from?
Developing embryos
What can embryonic stem cells develop into?
Any kind on specialised cell
What is asexual reproduction?
Where single-cell organisms (bacteria) can reproduce by dividing to form 2 new individuals (clones)
A gene provides instructions to make what?
Proteins
What does yeast produce via?
Asexual reproduction
