Genes, The Genetic Code, DNA and Chromosomes


Set of Flashcards for: 'Genes, The Genetic Code, DNA and Chromosomes' based on my Mindmap '8.1-8.2 Genes, The Genetic Code, DNA and Chromosomes' which is based on the AQA specification and also on the AQA Biology 2nd Edition AS and A level textbook
Bee Brittain
Flashcards by Bee Brittain, updated more than 1 year ago
Bee Brittain
Created by Bee Brittain about 8 years ago

Resource summary

Question Answer
What is a Gene? A gene is a section of DNA that codes for the amino acid sequence in a polypeptide chain and functional rRNA and tRNA
The point where a gene is fixed to on a DNA molecule is called a ________ Locus
How many different amino acids are there that are commonly found in living organisms? 20
How many bases (in DNA) are there? Name them in their complementary pairs. ((E.g/ Base 1 and Base 2)) There are 4 bases: -Adenine and Thymine - Cytosine and Guanine
How many bases code for one amino acid? What is the scientific name for these set of bases? 3 Bases which is commonly known as a triplet
Name the three features of the genetic code. Degenerate Non-Overlapping Universal
The Genetic Code is Universal (mostly), what does this mean? Universal means that the same triplets code for the same amino acid in all organisms, this is indirect evidence for evolution!
The Genetic code is also Degenerate, what does this mean? The code being degenerate means that most amino acids are coded for by more than one triplet
The genetic code is non-overlapping, what does this mean? It means that each base is only read once
Within genes, there are non-coding regions, what could these be? Introns Stop/start codes Multiple repeats
Within genes, what are the coding regions called? Exons
Name 4 facts about Prokaryotic DNA 1) Circular 2) Shorter 3) Not associated with proteins 4) Prokaryotes DON'T have chromosomes
Name 4 facts about Eukaryotic DNA 1) Linear 2) Longer 3) Associated with proteins 4) Eukaryotes DO have chromosomes
Name the protein associated with the structure of Chromosomes and DNA Histones
Which two organelles contain DNA? (Apart from the nucleus/nucleolus) Mitochondria and Chloroplasts, however although these are found Eukaryotic cells, they contain DNA similar to prokaryotic DNA
Vaguely describe how to structure of a chromosome occurs 1) DNA is in a double helix 2) Helix is wound around Histones that hold it in position 3) DNA-Histone complex is then further coiled 4) Coil is further looped and then coiled and packed into a chromosome
How many molecules of DNA does a chromosome contain? 1 Molecule
What is the name for a chromosome from a mother? Maternal Chromosome
What is the name for a chromosome from a father? Paternal Chromosome
What is a homologous pair? A homologous pair is a pair of chromosomes, one maternal, one paternal, that are similar but not identical
Homologous pairs are not identical, why is this? It is because even though they have the same genes in the same positions, they don't have the same alleles (versions of a gene). For example, both the maternal and paternal chromosomes will have the GENE for eye colour, but the maternal chromosome might have the ALLELE for brown eyes and the paternal chromosome might have the ALLELE for blue eyes.
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