9th grade Science practice sheet
Minnesota K-12 Academic Standards · from Gradelings · Name: ______________________
Question 1
Why do cells divide?
- To stop working
- To make non-living matter
- To get smaller
- To grow, replace old cells and repair damage
To grow, replace old cells and repair damage
Hint: Cell division lets organisms grow and heal.
Question 2
Meiosis is the type of cell division that produces…
- two identical nuclei
- identical body cells
- gametes with half the usual number of chromosomes
- new organelles
gametes with half the usual number of chromosomes
Hint: Gametes have half the chromosomes so that fertilization restores the full number.
Question 3
How many valence electrons (electrons in the outer shell) does boron (B) have?
- 5
- 3
- 2
- 4
3
Hint: Boron has 5 electrons in shells of 2, 3. The outer shell holds 3.
Question 4
Which pair would most likely form an ionic compound?
- carbon and oxygen
- sodium and chlorine
- hydrogen and hydrogen
- nitrogen and hydrogen
sodium and chlorine
Hint: A metal and a non-metal usually form an ionic compound.
Question 5
What is static electricity?
- Heat in a circuit
- A flow of charge in a wire
- A kind of battery
- A build-up of electric charge on an object
A build-up of electric charge on an object
Hint: Rubbing materials together can transfer electrons, leaving objects charged.
Question 6
Photosynthesis or cellular respiration? Sort each statement.
Sort into: ☀️ Photosynthesis · ⚡ Cellular respiration
- 🌫️Takes in carbon dioxide
- 🔋Happens in mitochondria
- 💨Releases oxygen
- 🐾Happens in plant and animal cells
- 🔥Breaks down glucose
- 🌿Happens in chloroplasts
☀️ Photosynthesis: Takes in carbon dioxide, Releases oxygen, Happens in chloroplasts · ⚡ Cellular respiration: Happens in mitochondria, Happens in plant and animal cells, Breaks down glucose
Hint: Photosynthesis builds glucose using light. Cellular respiration breaks glucose down to release energy.
Question 7
A difference between natural and artificial selection is that…
- in natural selection, the environment does the selecting
- in natural selection, humans choose
- only artificial selection involves traits
in natural selection, the environment does the selecting
Hint: In artificial selection, people choose.
Question 8
What is a gene?
- A section of DNA that carries instructions for a trait or protein
- A kind of organ
- A type of cell
- A protein only
A section of DNA that carries instructions for a trait or protein
Hint: Genes are the units of heredity: sections of DNA with instructions.
Question 9
A farmer wants every apple tree to produce the exact same apples. Which method is best?
- Planting seeds from the parent's apples
- Letting bees pollinate freely
- Grafting a cutting from the parent tree
- Crossing two different trees
Grafting a cutting from the parent tree
Hint: Apple seeds carry a mix of genes, so seeds give different apples. A graft is a clone.
Question 10
Group 1 elements, the alkali metals, are very reactive because they have…
- eight valence electrons
- no neutrons
- one valence electron that is easily lost
- a full outer shell
one valence electron that is easily lost
Hint: Losing one electron gives them a stable arrangement.
Answer key
- 1. To grow, replace old cells and repair damage (Cells from Cells)
- 2. gametes with half the usual number of chromosomes (Reproduction)
- 3. 3 (Atoms & Electrons)
- 4. sodium and chlorine (Electrons & Compounds)
- 5. A build-up of electric charge on an object (Electric Current)
- 6. ☀️ Photosynthesis: Takes in carbon dioxide, Releases oxygen, Happens in chloroplasts · ⚡ Cellular respiration: Happens in mitochondria, Happens in plant and animal cells, Breaks down glucose (Photosynthesis & Respiration)
- 7. in natural selection, the environment does the selecting (Evolution & Selection)
- 8. A section of DNA that carries instructions for a trait or protein (Cells from Cells)
- 9. Grafting a cutting from the parent tree (Reproduction)
- 10. one valence electron that is easily lost (Atoms & Electrons)
Want more than 10 questions?
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