8th Grade Science STAAR Review

Which statement about stars is correct?

• Star formation begins in a nebula.

• White dwarfs become main-sequence stars when they gain mass.

• Supergiants are stars that can absorb black holes.

• Main-sequence stars are formed by comets.

Tags

NGSS.HS-ESS1-1

NGSS.HS-ESS1-3

Based on their observations, can the students correctly conclude that a chemical reaction occurred?

• No, because the metal strip was still visible

• Yes, because a new material of a different color formed on part of the metal strip

• No, because the solution stayed blue

• Yes, because the volume of the blue solution stayed the same

Tags

NGSS.MS-PS1-2

To fight a bacterial infection, a patient was given an antibiotic to take for 10 days. After the patient finished taking the antibiotics as directed, almost all the bacteria were killed. After another 10 days, the patient was sick again with the same type of infection.

What most likely happened?

• A few bacteria survived the antibiotics and stopped reproducing.

• The patient’s high fever inactivated the antibiotic, allowing the surviving bacteria to grow

  rapidly.

• The antibiotic slowed the life cycle of the bacteria.

• Some of the bacteria were resistant to the antibiotic, and they reproduced.

Tags

NGSS.MS-LS4-4

A 1,100 kg car comes uniformly to a stop. If the vehicle is accelerating at - 1.2 m/s², which force is closest to the net force acting on the vehicle?

• -9,600 N

• -1,300 N

• -900 N

• -94 N

Tags

NGSS.MS-PS2-2

Why does autumn start in different months of the year in North America and South America?

• Earth’s orbit around the sun is not a perfect circle.

• North America has a larger landmass than South America.

• The moon has a greater pull on South America than on North America.

• Earth’s axis has a 23.5° tilt.

Tags

NGSS.MS-ESS1-1

What is the primary function of this body system?

• The protection of vital organs from injury

• The chemical breakdown of food into smaller pieces

• The transport of nutrients, water, and oxygen to body cells

• The production of hormones that regulate growth and metabolism

An ecosystem that is not sustainable can break down when a natural disaster occurs. This can lead to organisms in the ecosystem either leaving the area or dying off.

Increased biodiversity results in a more sustainable ecosystem because —

• a greater number of plant species means that there is less barren land

• a greater variety of species present allows more organisms to adapt after changes occur

• the transition area between two ecosystems is narrower

• there are fewer species to be affected by environmental stresses

Tags

NGSS.MS-LS2-4

NGSS.MS-LS2-5

Which statement describes the geologic process that is most likely responsible for the formation of these mountains?

• They are along a transform plate boundary that is no longer active, so erosion is creating deep valleys.

• They are along a transform plate boundary in which plates are currently moving side by side, causing earthquakes and faults.

• They are along a plate boundary in which plates are currently converging, causing uplift and steep slopes.

• They are along a plate boundary in which plates diverged in the distant past, allowing new rock to build up.

Tags

NGSS.MS-ESS2-2

An action–reaction pair of forces exists between —

• the aerialist’s feet and the rope

• the rope and the balancing bar

• the two ends of the rope

• the aerialist’s arms and legs

Tags

NGSS.MS-PS2-1

Lions and cheetahs prey on wildebeests that graze in the grasslands of the African savanna. What likely effect would increased rainfall over several rainy seasons have on the populations of wildebeests, lions, and cheetahs?

• All three populations would increase.

• The wildebeest population would decrease, and the lion and cheetah populations would increase.

• The wildebeest population would increase, and the lion and cheetah populations would decrease.

• All three populations would decrease.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4