Test 4 (Mass Transport, Protein Synthesis, Variation + Evolution) Flashcards
Prokaryotic DNA features
Free in cytoplasm
Shorter
No introns
Eukaryotic DNA features
Double stranded
Linear
Longer
Has introns
Define homologous pair
A pair with the same genes
In the same order
From 2 separate pairs
Define a diploid
2 complete sets of chromosomes
In a cell
One chromosome from each parents
What is splicing
Turns pre-mRNA into mRNA
Introns are spliced out
Functional exons are joined using enzymes
How do genes code for a protein
Three bases make a codon
Codon codes for amino acids
They form a polypeptide
Define a mutagenic agent
Something that increases rate of mutations
How is genetic variation increased
Random fusion of gametes
Produces new allele combinations
Define how gene mutation can have no effect on individual
Change in nucleotide
Causes new allele to form
Genetic code is degenerate
Changes amino acid
No effect on tertiary structure
How is chromosome number halved during meiosis
Homologous chromosomes
One of each goes to each daughter cell
Define the process of crossing over
Homologous pairs of chromosomes form a bivalent
Chiasma form
Alleles are exchanged
Produces new combinations of alleles
Differences between tRNA and mRNA
tRNA is clover leaf shape
mRNA is linear
tRNA has hydrogen bonds
mRNA has no hydrogen bonds
How is mRNA produced from an exposed template stand of DNA
Nucleotides form complementary base pairs
Phosphodiester bonds form
Due to RNA polymerase
How is a gene a code for the production of a polypeptide
Nucleotide sequence
In triplet codes
Determines primary structure of polypeptide
Define term exon
Nucleotide sequence coding for polypeptide primary structure
How is a phosphodiester bond formed between two nucleotides
Condensation reaction
Between phosphate and deoxyribose
Catalysed by DNA polymerase
Name the protein associated with DNA in a chromosome
Histone
How does an artériole reduce blood flow into capillaries
The muscle contracts
Narrows the lumen
Cardiac output equation
= heart rate x stroke volume
How does a small increase in pressure and in rate of blood flow in the aorta occur?
Elastic wall recoils
Smooths the blood flow
Maintains rate of blood flow
Advantage of Bohr effect during exercise
Increases dissociation of oxygen
For aerobic respiration at the tissues
What is the effect of increasing CO2 concentration on the dissociation of oxyhemoglobin
Increases oxygen dissociation
By decreasing blood pH
Name the blood vessels that carry blood to the heart muscle
Coronary arteries
Why does the initial binding of oxygen to haemoglobin make it easier for a second oxygen to bind
Initial binding changes the tertiary structure of haemoglobin
Uncovers another binding site
