🌱 Life Science – Challenge
1. Food Web
In a forest ecosystem: grass → grasshopper → frog → snake → hawk.
If snakes decrease sharply, what will MOST likely happen first?
A. Grasshopper population increases
B. Frog population increases
C. Hawk population decreases
D. Grass population decreases
2. Cells & Energy
Why do muscle cells have more mitochondria than skin cells?
A. They are larger in size
B. They need more energy for movement
C. They divide more often
D. They use sunlight for energy
3. Genetics – Punnett Square
In guinea pigs, black fur (B) is dominant to white (b). A Bb guinea pig is crossed with a bb guinea pig.
What percentage of offspring will be black?
A. 25%
B. 50%
C. 75%
D. 100%
4. Natural Selection
A population of insects is sprayed with insecticide. Most die, but a few survive. After many generations, almost all the insects are resistant. Why?
A. Insecticide caused a mutation
B. Insects adapted during their lifetime
C. Resistant insects survived and reproduced
D. Insecticide made them stronger
5. Human Body Systems
Which two systems work directly together to move your arm when you pick up a book?
A. Muscular and skeletal
B. Circulatory and nervous
C. Digestive and respiratory
D. Excretory and endocrine
⚡ Physical Science – Challenge
6. Density
A block of wood has a mass of 50 g and a volume of 100 cm³. What is its density?
A. 0.2 g/cm³
B. 0.5 g/cm³
C. 2.0 g/cm³
D. 5.0 g/cm³
7. States of Matter
Why does a balloon shrink when placed in the freezer?
A. Gas particles move faster in the cold
B. Gas particles slow down and occupy less space
C. Air escapes from the balloon
D. Cold air destroys gas particles
8. Newton’s Laws
A book slides across a table and slows to a stop. Which force causes it to stop?
A. Gravity
B. Friction
C. Normal force
D. Balanced force
9. Circuits
In a parallel circuit with 3 bulbs, what happens if one bulb burns out?
A. All bulbs go out
B. The other 2 bulbs stay lit
C. Current stops flowing
D. Voltage increases
10. Chemistry – Reactions
Magnesium reacts with oxygen to form magnesium oxide (MgO). Which evidence BEST shows a chemical change?
A. The magnesium melts
B. A white powder forms
C. The metal bends
D. The color stays the same
🌍 Earth & Space Science – Challenge
11. Plate Tectonics
Earthquakes and volcanoes are MOST common at:
A. The middle of tectonic plates
B. Plate boundaries
C. The equator
D. The poles
12. Climate Change
Why does melting Arctic sea ice affect global sea levels less than melting glaciers on land?
A. Glaciers are smaller than sea ice
B. Sea ice is less dense than water
C. Sea ice is already floating in water
D. Glaciers are not made of water
13. Rock Cycle
Which rock type forms from cooling magma or lava?
A. Sedimentary
B. Igneous
C. Metamorphic
D. Fossil rock
14. Space Science
Why does Earth experience seasons?
A. Earth’s orbit is a perfect circle
B. Earth’s axis is tilted
C. The Sun moves closer in summer
D. Earth rotates faster in winter
15. Data Interpretation
A graph shows the population of rabbits over 10 years.
-
Years 1–3: population rises quickly
-
Years 4–6: population levels off
-
Years 7–10: population declines
What is the BEST explanation for the decline?
A. Rabbits learned to reproduce less
B. Predators or limited resources reduced the population
C. Weather became warmer
D. Rabbits evolved into a new species
🌱 Life Science – Challenge
ReplyDelete1. C – Hawk population decreases
If snakes decrease, frogs increase (less predation). Hawks lose food (snakes) first → their population drops.
2. B – They need more energy for movement
Muscles contract and move → high energy demand → more mitochondria.
3. B – 50%
Bb × bb → offspring: Bb, Bb, bb, bb → 2 black : 2 white → 50% black.
4. C – Resistant insects survived and reproduced
Natural selection: survivors pass resistance genes on.
5. A – Muscular and skeletal
Muscles pull on bones to move the body.
⚡ Physical Science – Challenge
6. B – 0.5 g/cm³
Density = mass ÷ volume = 50 ÷ 100 = 0.5 g/cm³.
7. B – Gas particles slow down and occupy less space
Cold = less energy → particles move slower → lower volume → balloon shrinks.
8. B – Friction
Friction between book and table slows it down.
9. B – The other 2 bulbs stay lit
Parallel circuits have multiple paths; one broken bulb doesn’t stop the others.
10. B – A white powder forms
New substance (magnesium oxide) forms = evidence of chemical reaction.
🌍 Earth & Space Science – Challenge
11. B – Plate boundaries
Most earthquakes and volcanoes occur where plates meet.
12. C – Sea ice is already floating in water
Floating ice already displaces water; land glaciers add extra water when they melt.
13. B – Igneous
Formed when magma or lava cools and solidifies.
14. B – Earth’s axis is tilted
Tilt causes different sunlight angles → seasons.
15. B – Predators or limited resources reduced the population
Carrying capacity reached; decline due to food shortage, disease, or predators.