Question 1

Which of the following best describes the process of natural selection as proposed by Charles Darwin?

Accepted Answer

Individuals with inherited traits that are better suited to the environment tend to survive and reproduce more successfully, leading to the accumulation of favorable traits in the population over generations.

Question 2

A scientist is testing the effect of a new fertilizer on plant growth. She sets up two groups: one receives the fertilizer, and the other does not. She measures the height of the plants after four weeks. In this experiment, what is the dependent variable?

Accepted Answer

The height of the plants after four weeks

Question 3

Which of the following is NOT a property of life?

Accepted Answer

Ability to photosynthesize

Question 4

Which subatomic particle is primarily responsible for the chemical behavior of an atom?

Accepted Answer

Electron

Question 5

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

12

Question 6

Which of the following statements about radioactive isotopes is TRUE?

Accepted Answer

Radioactive isotopes decay because their nuclei are unstable, emitting particles and energy.

Question 7

Which element is considered a trace element in the human body and is essential for thyroid hormone production?

Accepted Answer

Iodine (I)

Question 8

A carbon atom has 6 protons, 6 neutrons, and 6 electrons. What is its atomic mass?

Accepted Answer

$$12$$

Question 9

Which of the following best explains why carbon-14 dating cannot be used to determine the age of dinosaur fossils?

Accepted Answer

The half-life of carbon-14 is too short to date materials millions of years old.

Question 10

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electron pairs between atoms

Question 11

If an atom has an atomic number of $$Z$$ and a mass number of $$A$$, which equation correctly gives the number of neutrons ($$N) in $$the atom?

Accepted Answer

$$N = A - Z$$

Question 12

Which of the following is an example of a real-world application of radioactive tracers in medicine?

Accepted Answer

Using iodine-131 to treat hyperthyroidism

Question 13

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule is a group of atoms bonded together, while a compound is a molecule that contains at least two different elements.

Question 14

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, creating partial charges on the molecule.

Question 15

A scientist is graphing the results of an experiment. On which axis should the independent variable be plotted?

Accepted Answer

X-axis

Question 16

Which of the following best describes the unity and diversity of life?

Accepted Answer

All living organisms share a common genetic code but exhibit a wide variety of forms and adaptations.

Question 17

Which of the following is a correct statement about electron shells and valence electrons?

Accepted Answer

Valence electrons are found in the outermost electron shell and determine chemical reactivity.

Question 18

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom

Question 19

Which of the following best explains why elements are arranged in the periodic table according to their atomic number?

Accepted Answer

Atomic number reflects the number of protons, which determines the element's identity and chemical properties.

Question 20

A patient receives a radioactive tracer for a PET scan. The tracer decays with a half-life of 2 hours. If the initial dose is 16 mg, how much tracer remains after 6 hours?

Accepted Answer

$$2 	ext{ mg}$$

General Biology Study Guide: Scientific Inquiry and Chemistry of Life

Guida di studio - Domande di pratica

Study guide - Flashcard