PIMSO 2022 - Science - Grade 4 - National Round

Question 1

Question 2

The following image shows the food web in the Philippine seagrass community. Which is not a primary consumer?

Figure reference: Edwards AJ, Impact of climate change on coral reefs, mangroves and tropical seagrass ecosystems, 1995.

1. Dugong
2. Sea urchin
3. Siganid
4. Zooplankton
5. Crab

Question 3

1. The undigested lactose causes the symptoms directly.
2. The undigested lactose irritates the lining of the small intestine.
3. The undigested lactose reacts with fiber in the large intestine.
4. The undigested lactose is digested by the gut bacteria instead.
5. The undigested lactose attracts water and solutes to fecal material.

Question 4

1. Insulin is produced by the islets of Langerhans in the spleen in response to increased glucose in the bloodstream.
2. Insulin enables the transport of glucose from the blood to the liver to be converted and stored as glycogen.
3. Insulin facilitates the uptake of glucose by the muscle to be used as energy.
4. Insulin allows the uptake of fatty acids by the adipose tissue to be converted and stored as triglycerides.
5. All of the above are true.

Question 5

1. Bone
2. Tendon
3. Cartilage
4. Ligament
5. Joint

Question 6

The Omicron variant is observed to be a less morbid variant of the SARS-CoV-2 virus, the causative agent of the COVID-19 disease. Researchers have found that the decreased morbidity was due to differences in the preferred infection sites, in comparison to the previous variants. Which part/s of the respiratory system would the Omicron variant infect more?

A. a only
B. d only
C. e only
D. b and c
E. d and e
Editorial response: Interpret the labels and discuss the limits of the supplied comparison.

Question 7

1. is less than 3.08 g
2. is greater than 3.08 g
3. is 3.08 g
4. may vary
5. 1.00 g

Question 8

Shown below are test tubes containing different materials. The particles comprising the material are illustrated. As tiny spheres. Which test tube illustrates a gas?

1. a (left test tube)
2. b (middle test tube)
3. c (right test tube)
4. None of the above
5. Cannot be determined

Question 9

You poured cold water in a glass and put it out of the balcony on a humid summer day. After some time, you noticed that the water level lowered and some drops appeared on the sides of the glass. Which of the following best explains the appearance of water droplets on the outside of the glass?

Original image credit: Theo7705, own work, CC BY-SA 4.0. https://commons.wikimedia.org/w/index.php?curid=48913057

1. Some of the water was absorbed by the glass
2. Some of the water was absorbed by the glass and went to the outer side
3. Some water evaporated
4. Some water vapor condensed on the sides of the glass
5. None of the above

Question 10

1. solid
2. liquid
3. gas
4. plasma
5. all have the same energy

Question 11

Rice is a staple not only in the Philippines but in most south-east Asian countries as well. It is typically washed well before cooking. Rice is typically added with the same volume of water. Once the water starts to boil at 100 C, it is advised to lower the heat, while maintaining the boiling, until the rice cooks. What happens to the temperature while the water is boiling?

Original image credit: gran, own work, CC BY 3.0. https://commons.wikimedia.org/w/index.php?curid=10216705

1. increases
2. stays constant
3. decreases
4. fluctuates between 90 and 100 C
5. Cannot be determined

Question 12

1. Salt has a higher density
2. Both containers of salt and sugar occupy the same volume so they contain the same amount of matter
3. If both are sold at the same price, the container with salt turns out to be cheaper per amount material
4. a and c
5. a, and b

Question 13

A container ship left Manila Bay at 5:00 am. The following graph shows its speed over time. When does the ship have a non-zero acceleration?

A. From 5:00 am to 7:00 am and from 9:00 am to 10:00 am
B. From 7:00 am to 9:00 am and from 10:00 am to 1:00 pm
C. From 5:00 am to 1:00 pm
D. From 7:00 am to 9:00 am, from 10:00 am to 11:00 am, and from 1:00 pm to 3:00 pm
E. From 1:00 pm to 3:00 pm
Editorial response: Explain the science and limitations in the choices.

Question 14

Water feels refreshing especially on hot summer days. Going to the beach, swimming pools, or water parks is a fun way to “beat the heat”. This illustrates what property of water?

Original image credit: Branko Radovanović, own work, CC BY-SA 3.0. https://commons.wikimedia.org/w/index.php?curid=26354350

1. Low thermal conductivity
2. High thermal conductivity
3. Low heat capacity
4. High heat capacity
5. None of the above

Question 15

1. 60 km/hr
2. 90 km/hr
3. 36 km/hr
4. 50 km/hr
5. None of the above

Question 16

Question 17

What property of light changes when it travels through a different medium that makes the pen look bent?

Original image credit: Ulflund, own work, CC0. https://commons.wikimedia.org/w/index.php?curid=73684026

1. wavelength
2. speed
3. intensity
4. focus
5. refraction

Question 18

1. red
2. yellow
3. green
4. blue
5. indigo

Question 19

1. This layer is mostly comprised of sand and clay.
2. This shelf covers the shore down to the deep ocean.
3. This layer is dark in color due to the high concentration of minerals, thus nurturing plant growth.
4. This layer mostly consists of large objects such as stones and rocks.
5. This layer ranges down to the deepest parts of the earth’s crust.

Question 20