DNA
What is deoxyribose?
The sugar in DNA
What is a karyotype?
An arrangement of all the chromosomes from the nucleus arranged in order from largest to smallest
Define allele
An alternative form of a gene
Name the 4 phases of mitosis (in the correct order)
Prophase, metaphase, interphase, anaphase
How many genes make up the human genome?
Around 20 000
What type of bond connects the nitrogen-rich bases?
Hydrogen bond
Name 2 mutagens
Ionising radiation, chemicals such as formaldehyde, viruses, bacteria
Distinguish genotype from phenotype
Genotype - genetic makeup of an individual
Phenotype -observable characteristics of the individual
Describe the structure of a replicated chromosome
2 chromatids joined at the centromere
Give one example of gene technology
Where in a cell is DNA found?
Nucleus and mitochondrion
Name the 3 types of gene mutations
Substitution, insertion, deletion
What are homologous chromosomes?
Chromosomes with genes for particular characteristics at the same location
Name the type of cell division and the stage at which crossing over occurs
Meiosis
Prophase I
What is recombinant DNA?
DNA that has been formed artificially by combining genetic information from different organisms
Name the 4 nitrogen-rich bases found in DNA
Adenine, thymine, cytosine, guanine
What is the difference between a somatic and a germ cell mutation?
Somatic - occurs in body cells (not inherited)
Germ cell - occurs in the gametes (inherited)
What is another name for a trait?
A characteristic
How many autosomes in a gamete?
22
What is a plasmid?
Circular DNA found in bacteria
Give the full names of the 2 scientists awarded the Nobel Prize for working out the double helix structure of DNA
James Watson and Francis Crick
How many chromosomes does a person with trisomy-21 have?
47
What is the name given to the trait that is observed in the outward appearance of a heterozygous individual?
Dominant
Define cytokinesis
The division of the cytoplasm to form daughter cells
What is the name of the 'glue' (an enzyme) used to join pieces of DNA?
Ligase