PIMSO 2025 - Science - Primary 2 - National Round

Question 1

The diagram below shows the longitudinal section of a fertilized chicken egg. In which part of the egg would the chick embryo develop?



Source: https://edis.ifas.ufl.edu/pdf/4H/4H36800.pdf

1. A
2. B
3. C
4. D

Question 2

The engineering behind the nose shape of the Japanese bullet train was inspired from the beak of kingfisher. How is that so?



Sources: https://www.jrailpass.com/blog/wp-content/uploads/2019/08/shinkansen-n700s.jpg ; https://cdn.download.ams.birds.cornell.edu/api/v1/asset/168729731/1800

A. The bullet train can be built longer than an average train.
B. It enables the bullet train to run at a higher speed with less drag.
C. It enables the bullet train to run silently inside tunnels.
D. The bullet train can run more smoothly and comfortably at higher speed.

Editorial review: explain which design benefits are supported and which wording is too strong.

Question 3

1. Waxy epithelium
2. Fine shallow roots
3. Tough spines
4. Hair-like spines

Question 4

1. Vitamin A: Blindness
2. Vitamin B12: Brittle bones
3. Iodine: Enlarged thyroid
4. Calcium: Muscle cramps

Question 5

1. Skull
2. Ribs
3. Spinal column
4. Pelvic bone

Question 6

1. The virus enters the body through the nose from the hand.
2. The virus enters the body through the nose from the infected surface.
3. The virus enters the body through the wound opening in the skin.
4. The virus enters the body through the pores in the skin.

Question 7

1. Mass
2. Color
3. Density
4. Volume

Question 8

Distillation is a process used to purify liquids such as water. A diagram is shown below. In the first stage of the process (labeled A), the liquid is heated to a temperature that will transform it to the gas phase. Then, in the second stage (B), the gas is trapped and allowed to cool down to return it to the liquid phase. What process does the heating do to the liquid in the first stage?



Adapted from Theresa Knott; derivative work John Kershaw. CC BY-SA 3.0. https://commons.wikimedia.org/w/index.php?curid=4219544

1. Condensation
2. Heating
3. Melting
4. Evaporation

Question 9

Rod failed a mathematics exam, so he wants to hide the paper from his parents. But he wants to throw it in the proper bin. Which bin should he throw it to?

A. In the bin that has the symbol
B. In the bin that has the symbol
C. In the bin that has the symbol
D. It is a failed math test; any bin will do

Editorial review: explain the scientific ambiguity in the original choices.

Question 10

Question 11

1. Sugar
2. Salt
3. Sand
4. Cement

Question 12

1. Gas has a fixed shape and size.
2. Liquid has a fixed shape and size.
3. Solid has fixed shape and size.
4. Solid does not have shape and size.

Question 13

Which of these will bounce the highest when dropped onto a floor?



Editorial assumption: ordinary pictured objects, dropped from the same height onto the same floor.

1. a pillow
2. a stone
3. a ball
4. an apple

Question 14

Lorena has this pebble. How many centimeters (cm) long is the pebble?

1. 2
2. 5
3. 7
4. 9

Question 15

Transverse waves are often used to represent sound waves. A large amplitude indicates a loud sound and short wavelength indicates a high-pitched sound. The diagram below illustrates a portion of a sound wave. Which diagram illustrates a sound wave that is louder than the one shown above? (C)





Source note: the parenthetical letter is already printed in the original question.

A. A (see original diagrams)
B. B (see original diagrams)
C. C (see original diagrams)
D. D (see original diagrams)

Editorial review: explain the scientific ambiguity in the original choices.

Question 16

This diagram shows the effect of wind on sand grains of different sizes. What size of sand grains are likely to be moved farthest by the wind?

1. Large sand
2. Medium sand
3. Coarse sand
4. Fine sand

Question 17

Friction is a force that slows down the movement of objects. Some students recorded the time it took for one crate to slide down four ramps. The ramps were the same except for their surfaces. Which surface caused the most friction with the block?

1. cement
2. glass
3. wood
4. rubber

Question 18

1. increases
2. increases then decreases
3. decreases
4. constant

Question 19

Mr. Cruz found a caterpillar in his garden. He puts it on his finger and took a picture as shown below. What does his finger help to show?

1. temperature of the caterpillar
2. sex of the caterpillar
3. age of the caterpillar
4. size of the caterpillar

Question 20