7th Grade Practice

Which arrow represents the movement of both energy and carbon in this ecosystem?

• W, because the plants provide energy and carbon through food to the rabbit

• X, because the cloud provides energy and carbon through water to the rabbit

• Y, because the sun provides energy and carbon in the form of heat to the rabbit

• Z, because the sun provides energy and carbon in the form of light to the tree

Heat causes some substances to decompose or break into smaller substances. Atoms are not created or destroyed during this process; they are only rearranged. These reactions can be written as chemical equations. Which particle diagram best represents the conservation of atoms in this chemical reaction?

• Diagram A

• Diagram B

• Diagram C

• Diagram D

The table describes characteristics of cells from two different organisms that belong to different kingdoms. Which statement correctly explains a difference between Organism X and Organism Y?

• Organism X is more likely to have a lower body temperature than Organism Y because the cells of Organism X contain centrioles.

• Organism X uses more energy to remove waste than Organism Y because Organism X has round and irregularly shaped cells.

• Organism Y is more likely to make its own food than Organism X because Organism Y contains chloroplasts.

• Organism Y uses more resources to produce cells than Organism X because Organism X has round and irregularly shaped cells.

Creosote bushes are types of plants that grow in deserts. The roots of these plants release a toxic substance that prevents other plants from growing near them. Which of these describes the most likely effect the toxic substance released by a creosote bush has on its chances for survival?

• The toxic substance helps increase the chances of survival for the creosote bush because the bush will have less competition for water from other plants.

• The toxic substance decreases the chances of survival for the creosote bush because pollinators will be less likely to spread its pollen.

• The toxic substance helps increase the chances of survival for the creosote bush because animals will be less likely to nest in its branches.

• The toxic substance decreases the chances of survival for the creosote bush because the toxin will require the bush to need more water than the desert provides.

Synthetic finger joints can replace damaged joints in human hands. In the past, these joints were made out of soft plastic. They were flexible but wore down quickly and required replacement. Scientists are now making synthetic finger joints from different materials. When choosing a material to make synthetic finger joints, which of these is the least important factor for scientists to consider?

• the flexibility of the material

• the durability of the material

• the ability of the material to be accepted by body systems

• the ability of the material to be used in other parts of the body

A teacher placed an herbivorous fish and a plant in an aquarium with a closed lid next to a classroom window. The teacher leaves the aquarium tank unattended in the classroom every weekend. The teacher is confident that the fish and the plant will remain healthy each weekend. Which diagram best shows how the fish and plant are able to survive in the unattended aquarium?

• A

• B

• C

• D

Which of these describes what will happen as more sodium ions are added to the water in the beaker?

• All of the water molecules inside the beaker will move into the bag.

• Some of the water molecules inside the bag will move outside the bag and into the beaker.

• Some of the sodium ions inside the beaker will move into the bag.

• All of the sodium ions inside the bag will move outside the bag and into the beaker.

Based on the diagram about the excretory system, which of these organ systems interact with the excretory system?

• respiratory, integumentary, digestive, and urinary

• circulatory, skeletal, digestive, and endocrine

• respiratory, digestive, circulatory, and skeletal

• circulatory, muscular, digestive, and nervous

When air is sealed inside a glass bottle and placed in the freezer, what change will occur to the air inside the bottle?

• Decrease in air pressure inside the bottle

• Increase in volume of air inside the bottle

• Decrease in the number of particles inside the bottle

• Increase in the speeds of particles inside the bottle