What is an allele?
A version of a gene
What is an anticodon?
A sequence of three nucleotide bases at one end of a tRNA molecule that is specific to an mRNA codon
What is a chromatid?
One strand of a replicated chromosome
What is a chromosome?
A structure consisting of a long, coiled molecule DNA and its associated proteins, by which genetic information is passed from generation to generation
What is a codon?
A sequence of three bases on mRNA that codes for a specific amino acid
What is crossing over?
The process in meiosis I in which homologous chromosomes pair up, their chromatids wrap around one another and their alleles are exchanged at equivalent portions of chromatids. This creates genetic variation
What is an exon?
A sequence of DNA that codes for an amino acid sequence
What is a histone?
Proteins that, together with DNA, form chromosomes in the nuclei of eukaryotic cells
What are homologous chromosomes?
Chromosome pairs, one maternal and one paternal, with the same gene loci
What is indépendant segregation?
The random separation of homologous chromosomes in meiosis I that produces genetic variation
What is an intron?
A non-coding sequence of DNA
What is a locus?
The position of a gene on a chromosome
What is a mutagenic agent?
An agent that increases the rate of gene mutations above normal level
What is mRNA?
A type of RNA that carries genetic information from the nucleus to the ribosome for protein synthesis. It is a single helix consisting of thousands of mononucleotides
What is species richness?
A measure of the number of different species in a community at a given time. It is a measure of species diversity
What is species diversity ?
A measure of the number of different species and the abundance of individuals in each of these species within a community
What is splicing?
The process following transcription in eukaryotic cells in which introns are removed from pre-mRNA and exons are joined together to from mRNA
What is tRNA?
A form of RNA that carries specific amino acids to the ribosomes. It is single-stranded and takes a clover-leaf shape. One side is longer than the other enabling the attachment of an amino acid. At the opposite end is an anticodon specific to the amino acid
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TOPIC 1 - BIOLOGICAL MOLECULES90
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TOPIC 2 - A: cell structure and division57
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TOPIC 2 - B: cell membranes25
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TOPIC 2 - C: cells and immune system47
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TOPIC 3 - A: exchange and transport systems 129
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TOPIC 3 - A: exchange and transport systems 270
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TOPIC 3 - mass transport in plants50
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TOPIC 4 - A: DNA, RNA and protein synthesis26
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TOPIC 4 - B: Diversity and selection32
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TOPIC 4 - C: Diversity and classification20
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TOPIC 4 DEFINITIONS18
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TOPIC 5 - Photosynthesis23
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TOPIC 5 - Respiration29
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TOPIC 5 - Energy and ecosystems16
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TOPIC 5 - Nutrient cycles22
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TOPIC 6 - A: Stimuli and Responses28
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TOPIC 6 - B: Nervous coordination50
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TOPIC 6 - C: Homeostasis31
