STAAR Reporting Category 2

A model of an enzyme and its corresponding substrate is shown.

Which model best represents the molecule at the end of the reaction?

• 
• 
• 
• 

Answer explanation

At the end of this chemical reaction, the enzyme remains unchanged, and the substrate has been broken down.

Which statements best compare a function of proteins and lipids in a human cell?

• Proteins provide energy for cellular processes. Lipids catalyze chemical reactions inside the cell.

• Proteins catalyze chemical reactions inside the cell. Lipids allow for the transport of certain molecules into and out of the cell.

• Proteins allow for the transport of certain molecules into and out of the cell.

  Lipids store genetic information for cells.

• Proteins store genetic information for cells. Lipids provide energy for cellular processes.

Answer explanation

Proteins in the form of enzymes catalyze chemical reactions inside the cell. Lipids make up the cell membrane, which allows certain molecules to be transported into and out of the cell.

Both the respiratory system and the digestive system involve the uptake of necessary molecules from an animal’s surroundings. Alveoli are tiny sacs that aid in the exchange of carbon dioxide and oxygen in the lungs. Intestinal villi are tiny projections along the lining of the intestines used to take in nutrients from food passing through.

Which system must interact with the respiratory and digestive systems to transport gases and nutrients throughout the body?

• Endocrine

• Integumentary

• Immune

• Circulatory

Answer explanation

The circulatory system transports blood to and from the heart and the rest of the body. Nutrients and gases, such as oxygen, are dissolved in the blood. The circulatory system must interact with the respiratory and digestive systems to transport the nutrients and gases in the blood throughout the body.

Tags

NGSS.HS-LS1-2

What are the products of the cellular process in these organelles?

• I: glucose and carbon dioxide II: oxygen and water

• I: carbon dioxide and oxygen II: glucose and water

• I: oxygen and glucose II: water and carbon dioxide

• I: carbon dioxide and water II: glucose and oxygen

Answer explanation

Organelle I is mitochondria, where carbon dioxide and water are the products of the process of cellular respiration. Organelle II is a chloroplast, where glucose and oxygen are the products of the process of photosynthesis.

Tags

NGSS.HS-LS1-7

Water, sugar, and other important nutrients need to be transported from one part of a plant to another. Which statement correctly describes the interaction of the root and shoot systems during nutrient transport?

• The leaves take in water and sugar, which are then transported to the rest of the plant through vascular tissues.

• The roots take in water and sugar, which are then transported to the rest of the plant through vascular tissues.

• The leaves take in water and the roots produce sugar that are transported to the rest of the plant through vascular tissues.

• The roots take in water and the leaves produce sugar that are transported to the rest of the plant through vascular tissues.

Answer explanation

The roots take in/absorb water from the ground, and the leaves produce sugar through the process of photosynthesis. Water and sugar are transported throughout the plant via vascular tissues.

Tags

NGSS.MS-LS2-3

Which sequence represents the levels of organization found in a multicellular organism, from smallest to largest?

• Cell, Tissue, Organ, Organ System

• Organ System, Organ, Tissue, Cell

• Tissue, Organ, Organ System, Cell

• Cell, Organ System, Organ, Tissue

Answer explanation

The order of cell, tissue, organ, and organ system represents the smallest to largest levels of cellular organization.

Tags

NGSS.HS-LS1-2

Scientists determined the total mass of DNA from a sample of animal cells. The masses of equal numbers of cells were taken during three different stages of the cell cycle. Stage I contains cells massed during G1 of the cell cycle. Which statement best describes the cells during Stage II?

• The cells have replicated their DNA, but have not completed mitosis and cytokinesis.

• The cells have completed mitosis and cytokinesis without replicating their DNA.

• The cells have replicated their DNA and completed mitosis and cytokinesis.

• The cells have temporarily exited the cell cycle without replicating their DNA.

Answer explanation

During Stage II, the cells have replicated their DNA, but have not completed mitosis and cytokinesis. Therefore, the mass of DNA is double the mass of the DNA in stages I and III.

Tags

NGSS.HS-LS1-4

Which characteristic best distinguishes these cells as either prokaryotic or eukaryotic?

• The organization of the genetic material

• The location of the cytoplasm

• The role of the cell membrane

• The function of the flagella

Answer explanation

The organization of the genetic material is the best characteristic to distinguish these cells as either prokaryotic or eukaryotic.

The graph shows the oxygen consumed by an athlete during different stages of training.

Based on the graph, which process is occurring between minute 5 and minute 10?

• Nuclei are building amino acids for energy storage.

• Ribosomes are building carbohydrates to increase energy output.

• Chloroplasts are using energy to produce oxygen.

• Mitochondria are using oxygen to produce ATP.

Answer explanation

Mitochondria produce energy for cells. The increase in the consumption of oxygen between 5 and 10 minutes is due to mitochondria using oxygen to produce ATP.

Tags

NGSS.HS-LS1-7

Normal cells that have a contact inhibition feedback mechanism that prevents the cells from replicating when other cells are touched. A diagram of cells with contact inhibition and cells without contact inhibition is shown. Which statement best describes what will happen to cells in an organism that lack contact inhibition?

• The cells will continue to grow, causing a tumor in the body.

• The cells will replicate normally, replacing body cells that die.

• The cells will replicate until the food supply for each cell is used, causing each cell to die.

• The cells will stop replicating once one layer is produced, as other body cells will crowd them out.

Answer explanation

Contact inhibition is a mechanism that stops the cell cycle and prevents cells from performing replication/proliferation and growth. The cells in an organism that lack contact inhibition will continue to replicate/proliferate and grow, and potentially lead to the development of tumors.

Tags

NGSS.HS-LS1-3