Unit 1 Flashcards
Chloroplast
The photosynthetic unit of a plant cell, contains all the chlorophyll
Induced pluripotent stem cells
Somatic (adult) stem cells reprogrammed to enter an embryonic stem cell-like state
Mitosis
Nuclear division
Natural selection
The survival of the fittest, whereby only individuals with the most suitable genetic constitution for any set of circumstances pass their genes on. The frequency of an allele increases in a population if it provides a selective advantage.
Pluripotent stem cells
These are stem cells, with the potential to make any differentiated cell in the body
Bioinformatics
A process which combines computer science and statistical analysis to study genomes
Gene pool
Complete set of unique alleles in a species/population
Allele frequency
The prevalence of alternative versions of genes
Allele
One of the different forms of a gene
Mutation
Creates many alleles for one gene pool
Gene migration
The movement of alleles between populations by individuals arriving from a different population and breeding. These individuals have a different gene pool and therefore introduce new alleles into the population.
Genetic drift
Tends to occur in small populations and describes the change in allele frequency due to a chance event. Small populations that are isolated from each other can vary greatly due to changes in allele frequency.
Non-random mating
Does not change the frequency of alleles, but increases the number of homozygous individuals. Interbreeding is the most common form.
Chance
Changes to allele frequency due to random loss (individual may die/fail to reproduce before death resulting in an allele being lost)
Sexual selection
The non-random increase in frequency of DNA sequences that increase reproduction
Stabilising selection
The average phenotype is selected and the extremes don’t survive as well/may disappear
Disruptive selection
The extreme values of a phenotype survive
Directional selection
Only one extreme phenotype is selected over both the average and the opposite extreme
Speciation
The formation of a new species
Species
Group of organisms which can interbreed to produce fertile, viable offspring
Double helix
The double helical shape of a DNA molecule
Antiparallel
Running in opposite directions
Prokaryotes
An organism which lacks a membrane-bound nucleus
Eukaryotes
An organism which possesses a membrane-bound nucleus
Plasmids
A circular, self-replicating DNA molecule that carrie only a few genes
DNA ligase
An enzyme that facilitates the process by which fragments of DNA are joined together
Primers
A strand of nucleic acid that serves as a starting point for DNA
Leading strand
The strand of DNA that is being repeated continuously
Lagging strand
The strand of DNA that grows in the direction opposite to the movement of the growing fork. It is replicated in fragments
In vitro
Out with a living organism
In vivo
Within a living organism
DNA polymerase
An enzyme that synthesises DNA strands from individual nucleotides
Insertion
The addition of an extra nucleotide
Gene/point mutation
Deletion - gene
Loss of a section of DNA/number of nucleotides
Gene/point mutation
Translocation
Transposition of a length of DNA onto another chromosome
Chromosome structure mutation
Deletion - chromosome
Removal of a length of DNA from a chromosome
Duplication
Repetition of a series of nucleotides within a chromosome
Chromosome structure mutation
Inversion
The inversion/reversal of a section of DNA within a chromosome
Chromosome structure mutation
Substitution
The replacement of one nucleotide by another
Gene mutation
Genome
The entirety of an organism’s hereditary information
Genomics
The science of interpreting genes. The study of an organism’s genome using information systems/databases/computerised research tools
Genetics
The branch of biology that deals with hereditary, especially the mechanisms of hereditary transmission and the variation of inherited traits among similar or related organisms
Plastome
The genetic material that is found in plasmids in plant cells (e.g. in chloroplasts). It composes part of the entire genome of photosynthetic organisms.
Meristem
A growing point in a plant. Location of mitosis producing new cells.
Apical meristem
Growing points/regions of mitosis found at the tips of plant stems or roots allowing increase in length
Self-renewal
A property displayed by stem cells which allows them to produce more stem cells
Blastocyst
An embryo that has developed for 5-6 days after fertilisation
Differentiation
The process by which cells or tissues undergo a change towards a more specialised function.
Transcription
The production of mRNA from a DNA template
Intron
Part of the initial mRNA that is removed before translation
Exon
Part of the initial mRNA which is used to code for protiens
Translation
The sequencing of amino acids at ribosomes, based on the sequence of nucleotides in mRNA
mRNA/messenger RNA
Synthesised from a DNA template, resulting in the transfer of genetic information from the DNA molecule to the messenger RNA
tRNA/transfer RNA
A short strand of RNA that is twisted in on itself to expose 3 bases. Carries a specific amino acid to a ribosome.
rRNA/ribosomal RNA
The RNA that is a permanent structural part of a ribosome
RNA splicing
A process which removes the introns from a primary RNA transcript
Anticodon
A triplet of exposed bases on a tRNA molecule
Codon
A triplet of exposed bases on a length of mRNA
Ribosomes
Structures found in the cytoplasm where protein synthesis occurs.
