S3 Topics 1-3 Revision Unit 1

Which organelles are ONLY found in plant cells? Select as many as you think.

• Nucleus

• Vacuole

• Cell wall

• Cytoplasm

What happens in the first stage of mitosis?

• Two identical new daughter cells are formed

• Chromatids are pulled to opposite sides of the cell

• Chromosomes line up at the equator of the cell

• DNA replicates

What is the name of the structures that pull chromatids to opposite poles?

• Nuclear membrane

• Spindles

• Equator

• Centromere

During mitosis, where do chromosomes line up in the cell?

• Each edge

• Spindle

• Equator

• In a circle

What name is given to the shape DNA forms?

• Spiral staicase

• Double stranded helix

• Twist

• Deoxyribonucleic Acid

Each chromosome has sets of genes, what are genes? You may select more than one option.

• An order of bases

• Instructions for a characteristic

• They make up DNA

• They keep chromosomes warm

How many chromosomes do humans have?

• 92

• 23

• 46 pairs

• 46

Which of these describes a catalyst? Select as many as you think.

• Not changed by reaction

• Speeds up reaction

• Made of protein

• Made in living cells

Which of these describes an enzyme? Select as many as you think.

• Not changed by reaction

• Speeds up reaction

• Made of protein

• Made in living cells

Why do enzymes only work on a specific type of substrate?

• Enzymes only come in contact with a specific substrate

• Enzymes are picky

• Enzymes have a specific shape

• Substrates are only attracted to specific enzymes