Unit 1
Stem cells that can differentiate into all the cell types that make up an organism e.g. embryonic stem cells
Pluripotent
Part of an organisms life cycle that allows survival during periods when costs of continued normal metabolic activity would be too high
Dormancy
Dormancy which allows survival in periods of high temperature or drought
Aestivation
Describe the first stage of replication.
Double helix unwinds and hydrogen bonds between the bases break
What are the two functions of non-coding sequences in the genome?
1. Regulate transcription 2. produce transcribed but never translated RNAs (tRNA and rRNA)
DNA strand that is replicated in fragments
Lagging strand
Regulation of the internal environment, irrespective of the external environment, to create the optimum conditions for biological function
Homeostasis
Actions taken by effectors to return the internal environment to the homeostatic set point
corrective responses
Describe the second stage of PCR
DNA cooled to between 50-65°C to allow primers to bind to the target sequences
What is bioinformatics?
Study of comparative gene sequences using computers and statistics
Where genes are transferred between individuals in the same generation
Horizontal gene transfer
Circulatory system of amphibians and most reptiles that has two atria and one ventricle
Incomplete double circulatory system
A measurement of metabolic reactions over time
Metabolic rate
Describe the function of RNA polymerase.
Synthesises a primary transcript of mRNA from RNA nucleotides by complementary base pairing.
Describe the change in phenotype frequency as a resulf of disruptive selection.
In disruptive selection, two or more phenotypes are selected for.
Temperature required to separate DNA strands during PCR
Between 92 and 98°C
Stage of glycolysis where ATP are used to phosphorylate intermediate molecules
Energy investment phase
Stage of aerobic respiration involving a series of enzyme-controlled reactions that generate ATP and release carbon dioxide
Citric acid cycle
Describe at least two differences between RNA and DNA.
RNA single-stranded whereas DNA double-stranded, RNA contains the base uracil whereas DNA contains the base thymine, RNA contains a ribose sugar whereas DNA contains a deoxyribose sugar.
State the definition of evolution.
The changes in organisms over generations as a result of genomic variations.
Non-coding region of RNA found in eukaryotic cells.
Intron
Reactions that build up large molecules from small molecules. These reactions require energy.
Anabolic
Molecule which bind to the enzyme elsewhere than the active site but cause the shape of the active site to change, preventing the substrate from binding.
Non-competitive inhibitor
What does multipotent mean?
The stem cell can differentiate into all the types of cell found in that particular tissue type
Explain the importance of gene duplication in evolution.
Duplication allows potential beneficial mutations to occur in a duplicated gene whilst the original gene can still be expressed to produce its protein.