Keystone Review 4.11.23

Which characteristic is shared by all prokaryotic and eukaryotic organisms?

• contain genetic material

• contain membrane-bound organelles

• use the same method of reproduction

• use the same method of obtaining nutrition

Answer explanation

Prokaryotes and eukaryotes both have genetic material, but it is present in different forms among these groups.

Which conclusion is best supported by the presence of ribosomes in prokaryotes and eukaryotes?

• Ribosomes have different functions in prokaryotes and eukaryotes.

• Both prokaryotes and eukaryotes store energy to power life functions.

• Ribosomes developed independently inside prokaryotes and eukaryotes.

• Both prokaryotes and eukaryotes make proteins to perform life functions.

Answer explanation

Ribosomes serve as the site of protein synthesis; eukaryotes and prokaryotes are able to make proteins for cell growth and repair.

A molecule is produced within a ribosome in a cell. What most likely happens to the newly formed molecule once it is inside the Golgi apparatus of the cell?

• It will be used to form new genetic material.

• It will be stored for the cell’s future energy needs.

• It will be modified before it is packaged for transport.

• It will be broken down so its components can be reused.

Answer explanation

The Golgi apparatus functions to process proteins and sort

them for transport.

Which statement best explains why most biological macromolecules contain carbon?

• The long chains formed by carbon can be combusted with oxygen as a source of energy.

• Carbon exists across the universe and is produced in the interior of stars during their life cycles.

• Carbon can share electrons with up to four different atoms and form three types of bonding patterns.

• The chemical and physical characteristics of carbon-containing molecules change as they move through the carbon cycle.

Answer explanation

This ability to bond with many different atoms in different

forms and structures gives carbon the unique role of being present in many molecules.

Which statement best describes a relationship between enzymes and a simple

biological reaction?

• Enzymes will increase the amount of substrate formed during a biological reaction.

• Enzymes will decrease the amount of substrate formed during a biological reaction.

• A reaction rate can be increased when the specific enzyme for a biological reaction

  is present.

• A reaction rate can be decreased when multiple enzymes for a biological reaction

  are present.

Answer explanation

An enzyme decreases the activation energy of a specific

biological reaction, increasing the rate of reaction.

In order for medicine X to produce the effects that the researchers observed, it must have entered into which part of the targeted cells?

• nucleus

• ribosomes

• Golgi apparatus

• rough endoplasmic reticulum

Answer explanation

A medicine that damages DNA would need to enter a cell’s nucleus.

Most prokaryotes and eukaryotes maintain a reserve of ATP. Which feature of prokaryotes and eukaryotes makes the ATP reserve necessary?

• They have cell membranes.

• They can change over time.

• They use energy to function.

• They have the ability to reproduce.

Answer explanation

ATP is the energy currency of a cell, and both prokaryotes

and eukaryotes depend on ATP to fuel their cellular functions.

Which structure and function are common to all plants and some protists and distinguish them from all animals?

• chloroplasts that conduct photosynthesis

• mitochondria that conduct photosynthesis

• chloroplasts that conduct cellular respiration

• mitochondria that conduct cellular respiration

Answer explanation

Chloroplasts, which are absent in all animal cells, convert light energy into chemical energy within all plants and some protists.

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Cellulose is a carbohydrate and a polymer of glucose. Which statement best describes how cellulose is formed within living organisms?

• It is assembled by bonding individual atoms.

• It is constructed by connecting smaller monomer subunits.

• It is the product of the decomposition of a much larger molecule.

• It is the result of a physical change that alters the shape of a compound.

Answer explanation

Cellulose is a polymer, which is formed when many glucose monomers bond together.

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Many plants have a waxy coating on their leaves. Which statement describes the most likely structure and function of the waxy coating?

• The waxy coating is a protein that can help attract other organisms for pollination.

• The waxy coating is a protein that can help release waste molecules during transpiration.

• The waxy coating is a lipid that can help absorb more sunlight in hot environments.

• The waxy coating is a lipid that can help prevent excess water loss in dry environments.

Answer explanation

The waxy coating is a type of lipid molecule, and it prevents water loss.