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Cells
Molecules
Period Table
Ecosystem
100

What structure regulates what enters and leaves a cell?

  • A) Nucleus
  • B) Cell membrane
  • C) Ribosome
  • D) Cytoplasm

 B) Cell membrane

100

What is the basic unit of a chemical compound?

  • A) Atom
  • B) Molecule
  • C) Ion
  • D) Element

B) Molecule

100

What is the atomic number of an element?

  • A) The number of neutrons
  • B) The number of protons in the nucleus
  • C) The total number of electrons
  • D) The average mass of an atom

B) The number of protons in the nucleus

100

Define an ecosystem.

  • A) A community of organisms and their physical environment interacting as a system
  • B) A group of similar species
  • C) A single organism's habitat
  • D) The total number of organisms on Earth

A) A community of organisms and their physical environment interacting as a system

200

Describe the main differences between prokaryotic and eukaryotic cells.

  • A) Prokaryotic cells have a nucleus; eukaryotic cells do not.
  • B) Prokaryotic cells are generally larger than eukaryotic cells.
  • C) Eukaryotic cells have membrane-bound organelles; prokaryotic cells do not.
  • D) All of the above.

C) Eukaryotic cells have membrane-bound organelles; prokaryotic cells do not.

200

Define a covalent bond and provide an example.

  • A) A bond formed by the transfer of electrons; NaCl
  • B) A bond formed by sharing electrons; H₂O
  • C) A bond formed by magnetic attraction; Fe
  • D) A bond that does not involve electrons; Ar

B) A bond formed by sharing electrons; H₂O

200

Name the three types of subatomic particles.

  • A) Protons, electrons, and neutrons
  • B) Atoms, molecules, and ions
  • C) Nuclei, shells, and orbits
  • D) Elements, compounds, and mixtures

A) Protons, electrons, and neutrons

200

 What is the difference between a producer and a consumer?

  • A) Producers make their own food; consumers eat other organisms.
  • B) Producers are always animals; consumers are always plants.
  • C) Producers are larger than consumers.
  • D) There is no difference.

A) Producers make their own food; consumers eat other organisms.

300

What organelle is responsible for energy production in eukaryotic cells?

  • A) Golgi apparatus
  • B) Mitochondria
  • C) Lysosome
  • D) Endoplasmic reticulum

B) Mitochondria

300

Describe the structure of a water molecule and its significance to life.

  • A) It is linear and uncharged.
  • B) It is a polar molecule with hydrogen bonds.
  • C) It is a solid at room temperature.
  • D) It is a nonpolar molecule.

B) It is a polar molecule with hydrogen bonds.

300

How are elements arranged in the periodic table?

  • A) By atomic mass only
  • B) By increasing atomic number
  • C) Randomly
  • D) By color

B) By increasing atomic number

300

Explain the concept of a food chain and give an example.

  • A) A cycle of energy transfer; Grass → Cow → Human
  • B) A random arrangement of organisms; Lion → Zebra
  • C) A linear diagram of species; Tree → Bird
  • D) A list of all organisms in an ecosystem; All species included

A) A cycle of energy transfer; Grass → Cow → Human

400

Explain the role of the cell membrane in maintaining homeostasis.

  • A) It provides energy for the cell.
  • B) It regulates the movement of substances in and out of the cell.
  • C) It stores genetic information.
  • D) It synthesizes proteins.

B) It regulates the movement of substances in and out of the cell.

400

What are enzymes and how do they affect biochemical reactions?

  • A) They are lipids that slow down reactions.
  • B) They are proteins that speed up reactions.
  • C) They are carbohydrates that provide energy.
  • D) They are minerals that stabilize reactions.

B) They are proteins that speed up reactions.

400

What is the difference between a metal and a nonmetal?

  • A) Metals are good conductors; nonmetals are poor conductors.
  • B) Metals are gaseous at room temperature; nonmetals are solid.
  • C) Metals have high electronegativity; nonmetals have low.
  • D) All of the above.


A) Metals are good conductors; nonmetals are poor conductors.

400

What role do decomposers play in an ecosystem?

  • A) They produce energy through photosynthesis.
  • B) They consume primary producers.
  • C) They break down dead organic matter and recycle nutrients.
  • D) They compete for resources with primary consumers.

C) They break down dead organic matter and recycle nutrients.

500

What is the process called by which a cell engulfs material from its environment?

  • A) Exocytosis
  • B) Endocytosis
  • C) Diffusion
  • D) Osmosis

B) Endocytosis

500

Explain the significance of the pH scale in biological systems.

  • A) It measures the temperature of a solution.
  • B) It indicates the acidity or alkalinity of a solution.
  • C) It determines the density of a solution.
  • D) It tracks the concentration of nutrients.

B) It indicates the acidity or alkalinity of a solution.

500

Describe what an isotope is and provide an example.

  • A) Atoms with the same number of protons but different neutrons; Carbon-12 and Carbon-14
  • B) Atoms with different numbers of protons; Oxygen and Hydrogen
  • C) Atoms with the same mass; Helium-4 and Helium-4
  • D) Atoms that do not bond; Argon

A) Atoms with the same number of protons but different neutrons; Carbon-12 and Carbon-14

500

Discuss the impact of human activity on ecosystems and biodiversity.

  • A) Humans have no impact; ecosystems are self-sustaining.
  • B) Human activities can lead to habitat destruction and loss of biodiversity.
  • C) Human activities enhance biodiversity through agriculture.
  • D) All of the above.

B) Human activities can lead to habitat destruction and loss of biodiversity.