Question 1

Which of the following best describes the scientific method as presented in the lecture?

Accepted Answer

A flexible process that can involve exploration, hypothesis testing, and feedback in a non-linear fashion

Question 2

Which of the following is NOT a step in the classic model of the scientific method?

Accepted Answer

Ignoring contradictory results

Question 3

A good scientific question should be:

Accepted Answer

Testable and specific

Question 4

Which of the following statements about hypotheses is correct?

Accepted Answer

A hypothesis is a tentative explanation that can be tested by experiments

Question 5

Which element makes up the largest percentage of body mass in humans?

Accepted Answer

Oxygen

Question 6

Given the atomic number ($$Z) $$and mass number ($$A) of an $$element, which formula correctly calculates the number of neutrons ($$n$$)?

Accepted Answer

$$n = A - Z$$

Question 7

Radioactive isotopes are useful in biology because:

Accepted Answer

Their predictable decay allows for dating and medical imaging

Question 8

Which of the following best explains why atoms form chemical bonds?

Accepted Answer

To fill their valence electron shells and achieve stability

Question 9

What type of bond is formed between atoms with a large difference in electronegativity (greater than 1.7)?

Accepted Answer

Ionic bond

Question 10

If a sodium atom ($$Na) $$loses one electron, what is the resulting charge and name of the ion?

Accepted Answer

Positive; cation

Question 11

Which of the following statements about covalent bonds is true?

Accepted Answer

Electrons are shared between atoms

Question 12

Water ($$H_2O) is $$described as a polar molecule because:

Accepted Answer

Oxygen is more electronegative and attracts shared electrons more strongly

Question 13

How many valence electrons does carbon have?

Accepted Answer

4

Question 14

If carbon (electronegativity 2.55) bonds with hydrogen (electronegativity 2.20), what is the difference in electronegativity and what type of bond is formed?

Accepted Answer

Difference: $$0.35$$; nonpolar covalent bond

Question 15

Which of the following is a real-world application of radioactive isotopes in biology?

Accepted Answer

PET scans for medical imaging

Question 16

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 17

A molecule of methane ($$CH_4) is $$formed when carbon bonds with four hydrogen atoms. What type of bond is present and why?

Accepted Answer

Nonpolar covalent bond; small difference in electronegativity

Question 18

Which of the following best explains why filled valence electron shells make atoms stable?

Accepted Answer

Atoms with filled shells do not need to gain or lose electrons

Question 19

Which of the following elements is present in the human body at less than 0.01% of mass?

Accepted Answer

Zinc

Question 20

If an experiment produces results that contradict the original hypothesis, what is the most scientifically appropriate next step?

Accepted Answer

Revise the hypothesis and design new experiments

Introduction to Biology and the Scientific Method

Guida di studio - Domande di pratica

Study guide - Flashcard