A1.1 Water

Multiple Choice

Which of the following best describes the significance of water in the context of unity and diversity among living organisms?

• Water acts as a universal solvent, supporting diverse biochemical reactions.

• Water is only important for plants, not animals.

• Water is not involved in molecular processes.

• Water is only needed for hydration, not for chemical reactions.

Open Ended

Why is water considered essential for life at the molecular level?

Open Ended

What are the challenges and opportunities of water as a habitat?

Open Ended

What physical and chemical properties of water make it essential for life?

Multiple Select

Which of the following are consequences of hydrogen bonding in water?

• Cohesion of water molecules

• Adhesion to polar materials

• High solubility of nonpolar substances

• Low surface tension

Multiple Choice

Which key term describes the ability of water molecules to stick to each other due to hydrogen bonding?

• Cohesion

• Adhesion

• Viscosity

• Buoyancy

Open Ended

Explain how water acts as a medium for metabolic reactions and transport in living organisms, using examples from both plants and animals.

Multiple Choice

Which property of water is a direct result of the unequal sharing of electrons in its covalent bonds?

• Polarity

• Density

• Viscosity

• Transparency

Open Ended

Explain why water forms hydrogen bonds.

Multiple Choice

What causes the oxygen atom in a water molecule to have a slightly negative charge (δ-)?

• Oxygen has a higher electronegativity than hydrogen, attracting electrons more strongly.

• Oxygen is larger in size than hydrogen.

• Hydrogen atoms lose electrons to oxygen.

• Oxygen has more protons than hydrogen.

Multiple Select

Which of the following statements about hydrogen bonds in water are correct?

• Hydrogen bonds form between the hydrogen atom of one water molecule and the oxygen atom of another.

• Hydrogen bonds are stronger than covalent bonds within a water molecule.

• Hydrogen bonds are responsible for many of water's unique properties.

• Hydrogen bonds only occur within a single water molecule.

Open Ended

Distinguish between cohesion and adhesion.

Multiple Choice

What is the main difference between cohesion and adhesion?

• Cohesion is attraction between the same kind of molecules, while adhesion is attraction between different kinds of molecules.

• Cohesion is attraction between different kinds of molecules, while adhesion is attraction between the same kind of molecules.

• Cohesion involves hydrogen bonds, while adhesion does not.

• Adhesion only occurs in non-polar molecules.

Multiple Select

Which of the following statements about surface tension are correct?

• Surface tension is caused by the cohesive nature of water molecules.

• Surface tension allows some insects to walk on water.

• Surface tension is stronger in oil than in water.

• Surface tension is the property of a substance to resist an external force.

Open Ended

Explain how cohesion and adhesion work together to enable the transport of water in the xylem of plants.

Multiple Choice

Which of the following best explains why water is called the universal solvent?

• Because it is nonpolar and dissolves all substances

• Because it allows a wide variety of hydrophilic substances to dissolve in it due to its polarity

• Because it can dissolve only hydrophobic substances

• Because it is found everywhere in nature

Open Ended

Explain how water acts as a transport medium in both plants and animals, highlighting the differences and similarities.

Multiple Select

Which of the following substances are transported in water within animals?

• Nutrients

• Hormones

• Proteins

• Carbon dioxide

Multiple Choice

Why do cholesterol and lipid molecules require lipoprotein complexes for transport in blood?

• They are polar and dissolve easily in plasma

• They are nonpolar and do not dissolve in plasma

• They are ionic and bind to hemoglobin

• They are hydrophilic and mix with water

Open Ended

How does the theme of 'Unity and Diversity' relate to the molecular structure of water?

Open Ended

What questions do you still have about the properties or importance of water after today's lesson?