9th grade Science practice sheet
Alaska content standards · from Gradelings · Name: ______________________
Question 1
Before a cell divides, the DNA is…
- split into random pieces
- copied, so each new cell gets a full set
- removed from the cell
- destroyed
copied, so each new cell gets a full set
Hint: DNA replication ensures each daughter cell receives complete instructions.
Question 2
Why does sexual reproduction increase variety within a species?
- Offspring are copies of one parent.
- Parents choose which genes to pass on.
- Offspring get a new mix of genes from two parents.
- Mutations never happen.
Offspring get a new mix of genes from two parents.
Hint: Variation helps a species survive when conditions change.
Question 3
Argon (Ar) has atomic number 18. How many electrons does a neutral atom of it have?
answer box
18
Hint: In a neutral atom, the number of electrons equals the number of protons, which is the atomic number.
Question 4
Which pair would most likely form an ionic compound?
- nitrogen and hydrogen
- sodium and chlorine
- carbon and oxygen
- hydrogen and hydrogen
sodium and chlorine
Hint: A metal and a non-metal usually form an ionic compound.
Question 5
What are the products of cellular respiration?
- carbon dioxide, water and usable energy
- glucose and light
- oxygen and water only
- glucose and oxygen
carbon dioxide, water and usable energy
Hint: The energy released is used for growth, movement and repair.
Question 6
Which is the only common metal that is a liquid at room temperature?
- aluminum
- copper
- mercury
- iron
mercury
Hint: Mercury is liquid at about 20 °C.
Question 7
In CH₄ + 2O₂ → CO₂ + 2H₂O, how many hydrogen atoms are on the left side (reactants)?
answer box
4
Hint: CH₄ has 4 hydrogen atoms (the 2 in front of H₂O is on the other side).
Question 8
A new species can form when…
- populations become separated and adaptations build up over time
- one animal changes in a day
- two species are identical
populations become separated and adaptations build up over time
Hint: Over many generations, groups may become too different to breed together.
Question 9
A moving electric charge produces a…
- a shadow
- magnetic field
- a sound wave
magnetic field
Hint: This link is called electromagnetism.
Question 10
The SI unit of force is the…
- joule
- watt
- newton
- pascal
newton
Hint: N.
Answer key
- 1. copied, so each new cell gets a full set (Cells from Cells)
- 2. Offspring get a new mix of genes from two parents. (Reproduction)
- 3. 18 (Atoms & Electrons)
- 4. sodium and chlorine (Electrons & Compounds)
- 5. carbon dioxide, water and usable energy (Photosynthesis & Respiration)
- 6. mercury (The Periodic Table)
- 7. 4 (Chemical Change)
- 8. populations become separated and adaptations build up over time (Evolution & Selection)
- 9. magnetic field (Energy & Magnetism)
- 10. newton (Forces, Motion & Momentum)
Want more than 10 questions?
In Gradelings the questions change every time and adjust to your child, with hints and kind feedback. See all science units.