Cuestionario: Fundamentals of Biological and Physical Sciences — 10 preguntas

1. What is the primary purpose of the scientific method in biological research?

A. To prove hypotheses correct without testing

B. To observe phenomena without experimentation

C. To collect data without forming hypotheses

D. To systematically investigate hypotheses through experimentation and analysis

Answer: (D)

Explicación

The scientific method involves formulating hypotheses, conducting experiments, analyzing data, and drawing conclusions. It provides a systematic approach to investigate hypotheses and is fundamental in biological research.

2. Which SI unit is used to measure force in the SI system?

A. Kilogram (kg)

B. Meter (m)

C. Joule (J)

D. Newton (N)

Answer: (D)

Explicación

Force is measured in Newtons (N); kilograms measure mass, meters measure length, and Joules measure work.

3. Which of the following best describes Newton's second law of motion?

A. For every action, there is an equal and opposite reaction

B. Force equals mass times acceleration, expressed as F=ma

C. Energy cannot be created or destroyed, only transformed

D. An object at rest stays at rest unless acted upon by an external force

Answer: (B)

Explicación

Newton's second law states that force equals mass times acceleration (F=ma). It explains how the velocity of an object changes when it is subjected to an external force, forming a core principle of classical mechanics.

4. What is the primary function of enzymes in biological systems?

A. To increase the activation energy of reactions

B. To act as biological catalysts lowering activation energy

C. To provide energy directly to reactions

D. To change the equilibrium point of reactions

Answer: (B)

Explicación

Enzymes catalyze reactions by lowering activation energy, making reactions proceed faster without being consumed.

5. Why is water's polarity important in biological systems?

A. It enables hydrogen bonding, which contributes to water's high specific heat and solvent properties

B. It prevents water from mixing with other polar molecules

C. It causes water to be a solid at room temperature

D. It makes water a good conductor of electricity

Answer: (A)

Explicación

Water's polarity allows hydrogen bonding between water molecules, which is responsible for its high specific heat, surface tension, and excellent solvent properties—crucial for biological processes such as nutrient transport and chemical reactions.

6. According to Newton's laws, which statement is correct?

A. Inertia states that an object at rest stays at rest unless acted upon by an external force

B. Force equals mass divided by acceleration (F = m/a)

C. For every action, there is an equal and opposite reaction

D. Mass is the force exerted on an object by gravity

Answer: (A)

Explicación

Newton's first law states that an object will remain at rest or in uniform motion unless acted upon by an external force, illustrating inertia.

7. Which statement accurately describes the pH scale?

A. The pH scale ranges from 0 to 7, indicating acidity.

B. The pH scale is logarithmic, ranges from 0 to 14, and measures hydrogen ion concentration.

C. pH values above 7 indicate acidity, below 7 alkalinity.

D. The pH scale measures electrical conductivity of solutions.

Answer: (B)

Explicación

The pH scale is logarithmic, measures hydrogen ion concentration, ranges from 0 (most acidic) to 14 (most alkaline), with 7 being neutral.

8. What characteristic of water's polarity contributes to its high specific heat?

A. Water's nonpolar nature allows it to resist temperature changes.

B. Hydrogen bonding in water enables it to absorb and store heat effectively.

C. Water's ionic bonds make it resistant to temperature fluctuations.

D. Water's covalent bonds prevent rapid temperature changes.

Answer: (B)

Explicación

Hydrogen bonds between water molecules allow water to absorb and retain heat, resulting in high specific heat capacity.

9. In atomic structure, which particles define the element's atomic number and atomic mass respectively?

A. Protons and neutrons

B. Electrons and neutrons

C. Protons and electrons

D. Neutrons and electrons

Answer: (C)

Explicación

The atomic number is defined by the number of protons, and the atomic mass is roughly the sum of protons and neutrons in the nucleus.

10. Which statement correctly compares ionic and covalent bonds?**

A. Ionic bonds involve sharing electrons, covalent bonds involve transfer of electrons.

B. Ionic bonds involve transfer of electrons, covalent bonds involve sharing electrons.

C. Both ionic and covalent bonds involve transfer of electrons.

D. Both ionic and covalent bonds involve sharing electrons.

Answer: (B)

Explicación

Ionic bonds form due to transfer of electrons creating charged ions, while covalent bonds involve sharing electrons between atoms.