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level: All about DNA and variation

Questions and Answers List

level questions: All about DNA and variation

Question	Answer
Most cells in the human body contain a nucleus. What does the nucleus contain?	Chromosomes
What are the long, coiled length of molecule called that are contained in chromosomes?	DNA
What is the definition of DNA?	A list of chemical instructions on how to build an organism
What is the name for a short section of a chromosome?	Gene
What do genes control?	Our characteristics
How many genes work together, with one being dominant?	Two
How many chromosomes are found in a human cell?	46
How many chromosomes are found in the nucleus of egg and sperm cells?	23
What happens to the nucleus of an egg during fertilisation?	It merges with the sperm nucleus
How many matched pairs of chromosomes are found in a fertilised egg, with one set from the mother and one from the father?	23
What happens as a result of the mixture of chromosomes from both the mother and father in a fertilised egg?	A mixture of the parents characteristics are inherited
What is the name of the process where genes are passed down from parents to their children?	Heredity
What does the structure of a DNA molecule look like?	Double helix
Different species of organisms have different types of..?	Genes
You will see variation within the same species that basically have the same genes. This difference is a..?	Characteristic feature
Some characteristics are inherited from your parents, what other factor can affect characteristics?	Environment
What are the two types of variation that are seen within a species?	Continuous and discontinuous
What is the definition of continuous variation?	A feature that can vary over a range of values
What are examples of characteristics that are classed as continuous variation in humans?	Weight, height and skin colour
What is the definition of discontinuous variation?	Features that can only take certain values
What is an example of a characteristic that is classed as discontinuous variation in humans?	Blood group