Unit 4 - DNA Flashcards
What is DNA?
A molecule that carries genetic information in a cell
What is the monomer of DNA?
A nucleotide
What is a nucleotide made of?
- Phosphate
- Sugar (deoxyribose)
- Base
What bases can a nucleotide be made of?
- Adenine
- Thymine
- Guanine
- Cytosine
What is complementary base pairing? What does this mean in terms of bases?
It means that bases will always pair up with the same bases:
- Adenine and Thymine will always pair up
- Guanine and Cytosine will always pair up
How is DNA formed? What is its structure described as?
Nucleotides join together to form two longs strand of DNA, which then join together through hydrogen bonds that connect the complementary bases together. This structure is described as a double helix
Where is DNA found (eukaryotic cells)?
In chromosomes, which are found in the nucleus.
What are chromosomes made up of?
DNA molecules and proteins
What are genes?
Stretches of DNA that code for a trait/characteristic
How would you describe the genetic code? (2 words)
Universal and redunant
What does DNA code for?
Proteins
What determines what protein DNA codes for?
The order of bases
What is a codon?
Three letter base sequence that codes for a specific protein
Why is the genetic code considered redundant?
There are 20 amino acids but with a three letter base sequence, there are 64 possible codons (4 bases to the power of three). There are more codons than needed.
What are mutations?
Irreversible changes to the genetic code
Why are mutations usually very harmful? What/who do they harm the most?
The are harmful because they change the codon sequence which will produce either a dysfunctional protein or the wrong protein.
They can severely impact your gametes and your future offspring.
What is the name for something that causes a mutation? Give examples of these causes:
Mutagen:
- UV light
- Radiation
- Chemicals
What are the three types of mutations? Which is the least harmful?
- Substitution
- Deletion
- Addition
Substitution is the least harmful because it doesn’t affect the rest of the following genetic sequences.
What is a chromosome?
A structure made out of DNA and proteins that carries genetic information in the form of genes.
What base is different in an RNA strand?
Thymine turns into urasil
What is an allele?
An alternative form of a gene
What is a locus?
The location of a particular gene
What is a phenotype?
The physical appearance of an organism
What is evolution?
A change in phenotype
What is a telomere?
A stretch of non-coding DNA found at the end of a chromosome that protects the chromosome from damage during cell division
What are some factors that cause ageing?
- Decline of mitochondria function
- Genetic damage
- Shortening of telomeres
- Decrease in stem cell quantity
- Lack of protein control due to harmful substance build up
What is parkinsons disease?
A progressive neurological brain disease where brain cells that produce dopamine are damaged
What are the symptoms of parkinson’s?
- tremors
- stiffness
- changes in speech
What are the cures/preventions of parkinsons?
- No cure
- Deep brain stimulation mimics cells that have been damaged
- Some medecines help slow the progress of the disease
- aerobic exercise might help
What is the cause of parkison’s?
There is no known cause
What are the 6 stages of evolution?
- Variation + overpopulation
- Change in environment
- Struggle for existence
- Survival of the fittest
- Increased heritability
- Change in phenotype
