Division and Inheritance Flashcards
What is DNA?
Contains instructions to put an organism together and make it wokr
What does DNA stand for?
Deoxyribonucleic Acid
What are chromosomes?
Long molecules of DNA
Where are chromosomes?
In the nucleus
What does a gene do?
contains instructions to make a specific protein
Where are genes?
Small section of DNA
How do genes make proteins?
String amino acids in particular order
How many amino acids are used?
20
What determines what proteins are produced?
DNA
What determines what cell it becomes?
Proteins
What are different types of the same gene called?
Alleles
Whose DNA is not unique?
Identical twins and clones
What is DNA fingerprinting?
Cutting up a persons DNA and separating into small sections
What is DNA fingerprinting used for?
Paternity testing
Forensic science
Why should there be a national genetic database?
Crimescene DNA could be checked against everyone in the country
Why shouldn’t there be a national genetic database?
Invasion of privacy
Safe? (What else might be used for)
Errors and misinterpretations
Ho many pairs of chromosomes do humans have?
23
What is mitosis?
When a cell reproduces itself by splitting to form 2 identical offspring
What pulls apart chromosomes in mitosis?
Cell fibres
Which mi is asexual reproduction?
Mitosis
Why is there no variation with mitosis?
Same genes
What are gametes?
Sex cell
Why do gametes have 1 pair of each chromosomes?
So when they join the other gamete, they have the right amount
Which mi is sexual reproduction?
Meiosis
Why does sexual reproduction show variation?
Inherit features from both parents
Where does meiosis happen in humans?
Reproductive organs (testes and ovaries)
What is meiosis?
Produces cells with half the number of chromosomes
When does mitosis occur in human reproduction?
After the gametes have fertilised
When do animal cells loose the ability to differentiate?
Early stage
What are stem cells?
Undifferentiated cells that can develop into different types of cells
Where are stem cells found?
Early human embryo
Bone marrow
Umbilical cord?
Why embryo stem cells > bone marrow stem cells?
Bone marrow stem cells not as versatile (can’t turn into any cell)
How do stem cells treat sickle cell anaemia?
Turn into red blood cells
What conditions can stem cells help?
Heart disease (beating heart muscles) Diabetes (insulin producing cells) Spinal injuries (nerve cells)
How do scientists make stem cells change?
Change its environment
Why are stem cells hit and miss?
More research is needed
What are reasons for stem cells?
Save lives
Cure disease
Save costs
Would be thrown away anyway
What are reasons against stem cells?
No right to interfere
Religion
Killing humans?
At controls whether male or female?
23rd pair of chromosomes
What combination do males have?
XY
What combination do females have?
XX
What did Gregor Mendel do?
Need how characteristics were passed on in pea plants from one generation to the next
Ratio of tall pea plants to small pea plants?
3:1
Why did people not “believe” Mendel?
Not scientist (monk) Work wasn't widely published Genes weren't discovered yet
What do letter in genetic diagrams represent?
Alleles
What does homozygous mean?
Alleles that are the same
What does heterozygous mean?
Alleles that are different
The allele for the characteristic that’s shown is…?
Dominant
To display a recessive characteristic…?
Both alleles must be recessive
What is genotype?
The alleles
What is phenotype?
The actual characteristics
What is a mono hybrid cross?
Crossing 2 parents to look at 1 characteristic
What is cystic fibrosis and what does it do?
Genetic disorder where body produces thick sticky mucus in air passages and pancreas
Why type of allele is allele causing cystic fibrosis?
Recessive (carried by 1/25)
What is polydactyly?
Genetic disorder where baby born with extra fingers or toes.
Isn’t life threatening
What type of allele is the allele that cases polydactyly?
Dominant
What is embryo screening?
Cells from embryos can be analysed before being implanted into mothers womb during IVF
What happens after embryo screening?
Embryos with good alleles are implanted. Bad ones are destroyed
What does IVF stand for?
In Vitro fertilisation
What are reasons for embryo screening?
Stop suffering
Laws stop it going too far
Embryos destroyed anyway
Treating disorders cost money
What are reasons against embryo screening?
Pick most desirable baby
Killing humans?
Increase prejudice
Screening is expensive
Why don’t people think embryo screening isn’t justified for polydactyly?
Doesn’t affect health
