Friction
What force pulls objects down toward the Earth?
Answer: gravity
Explanation: Gravity is a force that attracts objects toward the center of the Earth. It’s the reason things fall when dropped.
Friction is a force that happens when two __________ rub against each other.
Answer: surfaces
Explanation:
Friction occurs when two surfaces — like your hands and a table, or your shoes and the ground — move against each other. This rubbing creates resistance, which slows things down or helps objects stop. The rougher the surfaces, the more friction is created.
What tiny living things can only be seen under a microscope?
Answer: microorganisms.
Explanation: Microorganisms are tiny living things like bacteria, fungi, and viruses. They’re too small to see with our eyes.
Which part of the flower receives pollen during pollination? A. Anther, B. Stigma, C. Petal, D. Ovary
Answer: B. Stigma
📝 Explanation: The stigma is the sticky part at the top of the pistil that catches pollen.
Why do plants disperse their seeds?
A. To get rid of bad seeds, B. To compete with other plants, C. To spread to new places and grow, D. To stop flowers from blooming
C. To spread to new places and grow
📝 Explanation: Dispersing seeds helps avoid competition and colonize new areas.
What do we call the force that we measure in newtons? A. Weight, B.Gravity, C. Air resistance, D. Water resistance
Answer: A.Weight
Explanation: Weight is the force of gravity acting on an object’s mass. It's measured in newtons (N) using a force meter.
What happens when there is too little friction?
A. It’s easier to climb a hill, B. Things stop moving, C. Objects move too slowly, D. Things can slip or slide easily
Answer: D
📝 Explanation: If there’s not enough friction, like on ice, it’s hard to stop or stay balanced.
Name one helpful microorganism used to make food.
Answer: Yeast
Explanation: Yeast is used to make bread rise, and certain bacteria are used to make yogurt and cheese.
2. What is the function of petals? A. Produce seeds, B. Attract pollinators, C. Transfer pollen, D. Absorb water
Answer: B. Attract pollinators
📝 Explanation: Petals are often brightly colored and scented to attract insects or animals.
A coconut is dispersed by: A. Animals, B. Wind, C. Water, D. Explosion
C. Water
📝 Explanation: Coconuts can float and are carried by water to new places.
Which force makes it harder for two surfaces to slide past each other?
Answer: friction
Explanation: Friction is a resistance force that happens when two surfaces touch. It helps with grip but can also slow things down.
Which surface would likely produce the most friction?
A. Ice, B. Smooth tile, C. Sandpaper, D. Glass
Answer: C
📝 Explanation: Sandpaper is rough, so it creates a lot of friction when objects slide over it.
Why are decomposer microorganisms important in nature? A. They make food taste better, B. They cause disease, C. They break down dead things into nutrients, D. They help in breathing
Correct answer: C. They break down dead things into nutrients.
📝 Explanation: Decomposers recycle nutrients by breaking down dead plants and animals.
Pollination is the process of...A. A seed growing into a new plant, B. Water entering the seed, C. Pollen moving from anther to stigma, D. A flower producing fruit
Answer : C. Pollen moving from anther to stigma
📝 Explanation: Pollination allows fertilization to take place.
What is the correct order of a flowering plant’s life cycle?
A. Seed → Flower → Germination → Pollination → Fertilization
B. Germination → Flowering → Pollination → Fertilization → Seed Dispersal
C. Pollination → Seed Dispersal → Fertilization → Germination → Flowering
D. Flowering → Germination → Seed Dispersal → Fertilization → Pollination
B. Germination → Flowering → Pollination → Fertilization → Seed Dispersal
📝 Explanation: This is the proper sequence from seed to new seed.
What can we do to an object’s shape to help it move better through air or water? A.Square. B. Flat, C. Streamlined, D.Rounded
Answer: C. streamlined
Explanation: Streamlined means designing a smooth shape that reduces resistance from air or water, helping the object move more easily.
A rough surface creates __________ friction than a smooth one.
Answer: more
Explanation: Rough surfaces have tiny bumps and ridges that catch against other surfaces when they rub together. This makes it harder for objects to slide, creating more friction. Smooth surfaces, like glass or polished wood, have fewer bumps, so objects slide more easily with less friction.
Which of the following is NOT a microorganism?
A. Bacteria, B. Virus, C. Mushroom, D. Fungi
Correct answer: C
📝 Explanation: Mushrooms are fungi, but they are not microorganisms because they are visible without a microscope.
What happens after pollination in flowering plants?
A. Seed dispersal, B. Fertilization, C. Germination, D. Petal formation
Answer: B. Fertilization
📝 Explanation: Fertilization occurs when pollen reaches the ovule inside the ovary.
Why do plants need to disperse their seeds?
Answer: To avoid overcrowding and help seeds grow in new places
Explanation: Dispersal helps seeds spread out so they don’t compete with the parent plant for space, sunlight, and nutrients.
What are the two forces that slow things down in air or water?
Answer: air resistance and water resistance
Explanation: These are friction-like forces that push against moving objects. Air resistance affects things moving through air, and water resistance affects things moving in water.
In your own words, explain what friction is and why it is important in our daily lives. Give at least one example.
Answer: Friction is a force that happens when two surfaces rub against each other. It helps slow things down or stop them. Friction is important because it helps us walk without slipping. For example, the friction between our shoes and the floor keeps us from falling.
Why is it important to wash your hands before eating or cooking?
Expected answer: To remove harmful microorganisms that might cause illness.
Name one condition needed for a seed to germinate.
Answer: Water (other acceptable answers: warmth, air/oxygen)
Explanation: Seeds need water to activate enzymes that start the growth process.
If you put one seed in a dark, warm place with water, and another seed in a sunny, dry place with no water, which one is more likely to germinate?
Answer: The seed in the dark, warm place with water
Explanation: Water and warmth are essential for germination; light is not always necessary at the start.