Q: A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$the solution? (Use $$[H^+] = 10$$^{-pH}$$)

$$[H^+] = 10$$^{-4}$$ \text{ M}$$

Question 1

Which of the following best describes the difference between a hypothesis and a theory in scientific research?

Accepted Answer

A hypothesis is a specific, testable statement that can be supported or refuted, while a theory is a broad explanation supported by a large body of evidence.

Question 2

Which of the following is NOT one of the seven properties common to all life?

Accepted Answer

Ability to photosynthesize

Question 3

A scientist observes that plants in sunlight grow faster than those in shade. She proposes that light increases the rate of photosynthesis, leading to faster growth. She then designs an experiment to test this. Which step of the scientific method is she performing when she proposes that light increases photosynthesis?

Accepted Answer

Forming a hypothesis

Question 4

Which of the following best describes the role of a control group in an experiment?

Accepted Answer

It is the group used for comparison, not exposed to the experimental variable.

Question 5

Which of the following correctly lists the levels of biological organization from smallest to largest?

Accepted Answer

Molecule, cell, tissue, organ, organism, population, ecosystem, biosphere

Question 6

Which of the following elements is NOT one of the four most common elements found in living organisms?

Accepted Answer

Calcium

Question 7

Why is fluoride added to drinking water in many communities?

Accepted Answer

To reduce tooth decay by strengthening tooth enamel

Question 8

Which of the following statements about isotopes is TRUE?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 9

A radioactive isotope is useful in medical imaging because:

Accepted Answer

It emits energy that can be detected, allowing visualization of biological processes.

Question 10

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are shared unequally, creating partial charges.

Question 11

Which property of water allows it to moderate temperature in living organisms?

Accepted Answer

Its high specific heat capacity

Question 12

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$the solution? (Use $$[H^+] = 10$$^{-pH}$$)

Accepted Answer

$$[H^+] = 10$$^{-4}$$ 	ext{ M}$$

Question 13

Which of the following best defines a buffer in biological systems?

Accepted Answer

A substance that resists changes in pH by accepting or donating H$$^+$$ ions

Question 14

Which of the following is an example of a compound?

Accepted Answer

H$$_2O$$

Question 15

In a saltwater solution, which component is the solute?

Accepted Answer

Salt

Question 16

Which of the following best describes the atomic number of an element?

Accepted Answer

The total number of protons in the nucleus

Question 17

Which of the following is a real-life example of a hydrogen bond?

Accepted Answer

The attraction between water molecules in liquid water

Question 18

Which domain includes multicellular organisms such as plants, animals, and fungi?

Accepted Answer

Eukarya

Question 19

A scientist is testing the effect of a new fertilizer on plant growth. She measures the height of plants after 4 weeks. In this experiment, what is the dependent variable?

Accepted Answer

The height of the plants

Question 20

Which type of reasoning is primarily used in discovery science?

Accepted Answer

Inductive reasoning

Biology Study Guide: Exploring Life & Chemical Basis of Life (Chapters 1 & 2)

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