1) Chromosomes are made of a) cytosine b) DNA c) protein d) sugar 2) The shape of a DNA molecule is called a... a) helix b) triple helix c) double helix d) twisted helix 3) Which is NOT one of the 4 base letters a) A b) G c) D d) C e) T 4) Which letter always pairs with A a) T b) C c) G d) A 5) Sperm and egg cells contain how many chromosomes? a) 13 b) 33 c) 43 d) 23 6) How many pairs of chromosomes are in a body cell? a) 42 b) 28 c) 23 d) 46 7) Which of the following is an example of continuous variation? a) eye colour b) blood type c) height d) petal colour 8) Which of the following is an example of discrete variation? a) blood type b) height c) hand span d) leaf size 9) Dominant genes are represented using a small letter a) true b) falsse 10) Which of the following is a phenotype a) Ww b) ww c) wrinkled seeds

DNA and inheritance

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