Biology Keystone Practice - Module 1

Which of the following is essential to proper functioning of ALL prokaryotic and eukaryotic organisms?

• ATP

• NaCl

Answer explanation

While not all organisms need oxygen, carbon dioxide, or table salt to survive, All organisms use ATP for energy.

Tags

NGSS.HS-LS2-3

Which statement BEST compares eukaryotic cells and prokaryotic cells?

• Eukaryotic cells are smaller than prokaryotic cells.

• Prokaryotic cells are more complex than eukaryotic cells.

• Prokaryotic cells contain a distinct central organelle, and eukaryotic cells do not.

• Eukaryotic cells contain a distinct central organelle, and prokaryotic cells do not.

Answer explanation

Eukaryotic cells contain a NUCLEUS that holds and protects the DNA. This is a big difference between them and their more simplistic prokaryotic ancestors.

Lungs and capillaries both have porous linings that allow certain substances to move into or out of the structures. Which function do these porous linings MOST LIKELY serve in living organisms?

• heat release

• gas exchange

• carbohydrate absorption

• osmotic pressure regulation

Answer explanation

In the lungs, oxygen from the environment is exchanged for carbon dioxide in the blood. This is essential for cellular respiration to occur.

Which property of water is MOST responsible for plants being able to transport water from their roots to their leaves?

• the attraction between molecules

• a capacity to dissolve many substances

• the ability to form low-density crystalline structures when frozen

• a capacity to absorb large amounts of energy as temperature increases

Answer explanation

This is called capillary action. Water molecules are attracted to each other and other substances due to hydrogen bonding. These joint forces pull water upward through thin tubes.

Tags

NGSS.MS-ESS2-4

The element carbon has multiple bonding patterns. Which bonding patterns CANNOT be formed by carbon?

Answer explanation

Which process BEST describes the assembly of proteins from amino acids?

• Atoms are linked to form a compound.

• Monomers are linked to form a polymer.

• Atoms are added to a monomer until it becomes a polymer.

• Molecules are added to a compound until it becomes a monomer.

Answer explanation

All polymers are made of repeating units called monomers. Proteins are a class of polymers built of monomers called amino acids.

Which statement BEST compares a carbohydrate and a nucleic acid?

• Carbohydrates store genetic information and nucleic acids store energy.

• Carbohydrates store energy and nucleic acids store genetic information.

• Carbohydrates assist diffusion across a plasma membrane and nucleic acids assist chemical reactions.

• Carbohydrates assist chemical reactions and nucleic acids assist diffusion across a plasma membrane.

Answer explanation

Carbohydrates (sugars) are the main source of energy for organisms. Nucleic acids (DNA & RNA) store your genetic information. Some proteins (transport proteins) assist in diffusion while another kind (enzymes) assist chemical reactions.

Each cell in the human body contains thousands of different enzymes responsible for regulating reactions within the cell. Which statement explains why a single enzyme is unable to regulate a variety of reactions?

• The binding of a product and an enzyme is specific.

• The binding of a substrate and an enzyme is specific.

• The enzyme is consumed by the products of the reactions.

• The enzyme is consumed by the substrates of the reactions.

Answer explanation

Enzymes are specialized proteins that speed up chemical reactions. Each enzyme only performs one chemical reaction. They must be able to fit perfectly with the substrate(s) they work with in order to function.

Which statement best describes a direct role of ATP in a paramecium?

• ATP provides the energy to move cilia

• ATP stores the genetic code for replication.

• ATP signals the presence of other nearby organisms

• ATP senses changes in the surrounding aquatic environment.

Answer explanation

In all living things, ATP is an energy molecule.

Tags

NGSS.HS-LS1-7

Which statement BEST describes a function of the proteins embedded in the plasma membrane of cells?

• They provide instructions for the processes in the cell.

• They selectively allow certain particles into and out of the cell.

• They attract charges in the cell’s environment to give the cell a net charge.

• They store the energy required by the rest of the membrane to perform its functions.

Answer explanation

Proteins embedded in the cell membrane are there to assist specific substances to pass through.