Grade 9 · Biology
Biology, chemistry, and physics questions from US classrooms. Written in American English for students, parents, and teachers in the United States.
Open a card to see the answer. These are original practice items for US elementary students — not a state test copy.
Answer: water across a membrane
Water moves toward higher solute concentration.
Answer: growth and repair of body cells
Daughter cells are genetically alike.
Answer: interphase and mitosis
DNA is copied in S phase.
Answer: make proteins
They read RNA.
Answer: lack a nucleus
Their DNA is in the nucleoid region.
Answer: swell
Water enters the cell.
Answer: an energy-carrying molecule
Cells use ATP to do work.
Answer: all living things are made of cells
Cells come from other cells.
Answer: chloroplasts
Chlorophyll captures light.
Answer: glucose and oxygen
6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
Answer: stomata
Guard cells open and close stomata.
Answer: sunlight
Light energy becomes chemical energy.
Answer: reflects green wavelengths
It absorbs red and blue light more.
Answer: breaks down glucose to make ATP
It is roughly the reverse energy path of photosynthesis.
Answer: light intensity, CO₂, or temperature
Too little light slows the rate.
Answer: water
Light reactions split water.
Pick the next article in this topic — that is how a magazine issue is meant to be used.
