GRADE 8 Science STAAR - 2022 Released Test

A photograph of a litter of six-week-old bulldog puppies shows that the puppies are not identical. Even though these puppies have the same parents, they do not all look alike because —

• they were produced by asexual cloning

• some of the puppies have genetic material from only one of the parents

• each puppy has a different combination of genetic material as a result of sexual reproduction

• all the puppies developed from the same fertilized egg

Sodium and lithium have similar chemical properties. What characteristic of these elements explains why they are chemically similar?

• Their atoms both have one valence electron.

• Their atoms both have more neutrons than protons.

• Their atoms have the same number of energy levels.

• Their atoms contain equal numbers of protons and electrons.

Which location around Green Peak is likely to experience the most erosion over time?

• Location W, because location W has the gentlest slope

• Location X, because location X is near the bottom of a slope

• Location Y, because location Y has the steepest slope

• Location Z, because location Z is the flattest slope

A student was given this partial dichotomous key and asked to determine in which of five orders the adult insect shown belongs. Based on the dichotomous key, in which order does the insect belong?

• F Diptera

• G Isoptera

• H Ephemeroptera

• J Zoraptera

The diagram shows a model of an atom. The model contains three different subatomic particles. Particles X and Y are inside the nucleus, and particle Z is outside of the nucleus. Which statements best describe the charges on the particles in this model?

• Both particles X and Y have a positive charge. Particle Z has a negative charge.

• Both particles X and Y have a negative charge. Particle Z has a positive charge.

• Either particle X or particle Y has a positive charge. Particle Z has a negative charge.

• Either particle X or particle Y has a negative charge. Particle Z has a positive charge.

A photograph of a bird perched on a fence post is shown. Which description best identifies the action-reaction pair between the bird and the fence post?

• Action: The force of the bird on the wires / Reaction: The force of the wires on the fence post

• Action: The force of the wires on the fence post / Reaction: The force of the fence post on the bird

• Action: The force of the fence post on the bird / Reaction: The force of the bird on the wires

• Action: The force of the bird on the fence post / Reaction: The force of the fence post on the bird

Farmers can best reduce negative effects on the water quality of nearby streams and lakes by planting crops that —

• produce less oxygen

• produce less carbon dioxide

• need less fertilizer

• need less solar energy

Buffelgrass is an invasive species of grass from Africa that outcompetes native Texas grasses for space and water. Which long-term change to a Texas grassland would most likely occur due to the introduction of buffelgrass?

• The population of native grasses will increase.

• The population of native grasses will decrease.

• Buffelgrass offspring will develop traits like those of native grasses.

• Buffelgrass offspring will develop traits like those of other invasive species.

Two students record the distance they each traveled in 60 seconds in the data table shown. If the students continue at the same speed, which statement describes the total distance traveled after 90 seconds?

• Student 1 traveled 40 m, and student 2 traveled 20 m.

• Student 1 traveled 50 m, and student 2 traveled 30 m.

• Student 1 traveled 60 m, and student 2 traveled 30 m.

• Student 1 traveled 70 m, and student 2 traveled 25 m.

A Hertzsprung-Russell (H-R) diagram is shown. A star that has a luminosity of 10^-2 and a temperature of 20,000 K is most likely a —

• Main sequence

• White dwarf

• Blue giant

• Red giant