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BIO340- Chapter 1
Question | Answer |
---|---|
Molecular Genetics | Structure & processes such as replication, transcription, and translation |
Transmission genetics | Mendelian genetics and its variations |
How many chromosomes in a human cell? | 46 |
How long is DNA in a human cell? | 2 meters |
How many DNA bases in a human cell? | 3 billion |
How many genes that code for proteins in a human cell? | 21,000 genes |
Reverse transcriptase | a type of DNA polymerase that uses an RNA template to synthesize DNA |
Where is reverse transcriptase commonly found? | retroviruses & retrotransposable elements |
What are the four levels of biological organization? | Molecular, cellular, organismal, population |
Small mutations | base substitutions (A to G) or length mutations (insertions or deletions) |
What's an example of a base substitution? | A to G |
What's an example of a length mutation? | Insertion or deletion |
What's PKU? | Phenylketonuria- a disease caused by the inability of an individual to break down amino acid phenylalanine into tyrosine |
PAH | a gene that codes for the enzyme PAH (phenylalanine hydroxylase) that catalyzes the chemical reaction of breaking down phenylalanine into tyrosine |
What happens if phenylalanine accumulates? | It's converted into phenylpyruvic acid in the liver which crosses the blood-brain barrier and is toxic to nerve cells; it affects the brain early in development and can cause mental retardation |
Compound heterozygote | When an individual has two different mutant alleles |
In terms of PKU, how is it that genotype doesn't necessarily determine phenotype? | Environment can affect whether or not someone has PKU because if it's caught early enough, the diet can be controlled and the brain can develop as it should |
BH4 | Tetrahydrobiopterin- a cofactor of PAH, And the alleles at four genes influence the production & recycling of BH4 |
BBB | Blood-brain barrier- prevents most molecules from entering the brain, and alleles at several genes affect the strength of the BBB |