[Sem 1] Biology Cells

Question 1

What are cells?

Answer 1

The building blocks of life, making up all living organisms, from trees to bacteria.

Question 2

Types of Cells

Answer 2

Unicellular (e.g., bacteria) and multicellular (e.g., animal cells).

Question 3

Cell Theory

Answer 3

1. All organisms are composed of one or more cells.
2. Cells are the basic unit of structure and function in organisms.
3. All cells come from other cells.

Question 4

Levels of Organization in Biology

Answer 4

1. Cell level
2. Tissue level
3. Organ level
4. Organ systems level
5. Organism level

Question 5

Eukaryotes

Answer 5

Multicellular organisms with DNA enclosed within a nuclear envelope, such as animal and plant cells.

Question 6

Prokaryotes

Answer 6

Single-celled organisms with DNA not enclosed in a nuclear membrane, such as bacteria and Archaeans.

Question 7

Cell Membrane

Answer 7

The outside layer of a cell that controls what goes in and out; it is semi-permeable.

Question 8

Cytoplasm

Answer 8

Everything inside the cell except the nucleus; includes cytosol.

Question 9

Nucleus

Answer 9

The control center of the cell, containing DNA and regulating gene expression and cell replication.

Question 10

Mitochondria

Answer 10

The “powerhouse” of the cell, producing ATP through cellular respiration.

Question 11

Ribosomes

Answer 11

Organelles that produce proteins using instructions from the nucleus; found in both eukaryotes and prokaryotes.

Question 12

Endoplasmic Reticulum (ER)

Answer 12

Rough: Produces proteins with ribosomes.
Smooth: Important for metabolism and lipid production.

Question 13

Vacuole

Answer 13

Stores water, nutrients, and waste; larger in plant cells.

Question 14

Cell Wall

Answer 14

Provides strength and support to plant cells, fully permeable.

Question 15

Chloroplast

Answer 15

Organelle in plant cells that produces glucose through photosynthesis using sunlight, CO2, and water.

Question 16

Lysosome

Answer 16

Breaks down large molecules and damaged organelles; involved in apoptosis.

Question 17

Golgi Complex

Answer 17

Packages and transports proteins for export out of the cell via exocytosis.

Question 18

Microscope Types

Answer 18

Compound microscope: Views living/non-living cells.
Stereo microscope: Observes large living specimens.
Electron microscope: Views extremely small organisms like bacteria and viruses.

Question 19

Cell Size

Answer 19

Cells are small to efficiently remove waste and absorb nutrients; small size ensures a high SA:V ratio.

Question 20

SA:V Ratio

Answer 20

Surface area to volume ratio; smaller cells have a higher SA:V ratio, facilitating faster exchange of materials.

Question 21

Diffusion

Answer 21

Movement of substances from high to low concentration; passive transport.

Question 22

Facilitated Diffusion

Answer 22

Diffusion assisted by carrier proteins; passive transport.

Question 23

Channel Proteins

Answer 23

Allow specific molecules (e.g., ions) to pass through the cell membrane; passive transport.

Question 24

Active Transport

Answer 24

Requires energy (ATP) to move molecules from low to high concentration.

Question 25

Osmosis

Answer 25

Movement of water from low to high solute concentration across a semipermeable membrane.

Question 26

Isotonic Solution

Answer 26

Solute concentration is the same inside and outside the cell; allows free movement of water.

Question 27

Hypotonic Solution

Answer 27

Solute concentration is greater inside the cell; water moves in, causing animal cells to burst and plant cells to become turgid.

Question 28

Hypertonic Solution

Answer 28

Solute concentration is greater outside the cell; water moves out, causing the cell to shrivel.