biology - cells

Question 1

What structures are found in both plant and animal cells?

Answer 1

Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, and rough endoplasmic reticulum (RER).

Question 2

What structures are found only in plant cells?

Answer 2

Cell wall, chloroplasts, and a large central vacuole

Question 3

What is the function of the nucleus?

Answer 3

Contains DNA and controls the activities of the cell

Question 4

What is the function of the cytoplasm?

Answer 4

Site of chemical reactions; contains enzymes.

Question 5

What is the function of the cell membrane?

Answer 5

Controls what enters and leaves the cell; selectively permeable.

Question 6

What is the function of mitochondria?

Answer 6

Site of aerobic respiration, producing energy.

Question 7

What is the function of ribosomes?

Answer 7

Site of protein synthesis.

Question 8

What is the function of the rough endoplasmic reticulum (RER)?

Answer 8

Transports proteins made by ribosomes.

Question 9

What is the function of the cell wall (plants only)?

Answer 9

Provides structural support; made of cellulose.

Question 10

What is the function of chloroplasts (plants only)?

Answer 10

Site of photosynthesis; contains chlorophyll.

Question 11

What is the function of the vacuole (plants only)?

Answer 11

Stores cell sap; maintains turgor pressure.

Question 12

How is a ciliated cell adapted to its function?

Answer 12

Has cilia to move mucus and dust out of airways.

Question 13

How is a root hair cell adapted to its function?

Answer 13

Long extension increases surface area for water and mineral absorption.

Question 14

How is a xylem vessel adapted to its function?

Answer 14

Hollow, lignified walls for water transport and support.

Question 15

How is a palisade mesophyll cell adapted to its function?

Answer 15

Packed with chloroplasts for photosynthesis; located near the leaf surface.

Question 16

How is a nerve cell adapted to its function?

Answer 16

Long axon to transmit impulses; branched endings to connect with other cells.

Question 17

How is a red blood cell adapted to its function?

Answer 17

Biconcave shape increases surface area; no nucleus for more haemoglobin.

Question 18

How is a sperm cell adapted to its function?

Answer 18

Tail for movement, many mitochondria, and enzymes to penetrate the egg.

Question 19

How is an egg cell adapted to its function?

Answer 19

Large with food store; special membrane that changes after fertilisation.

Question 20

What is a tissue? Give an example.

Answer 20

A group of similar cells working together (e.g., muscle tissue).

Question 21

What is an organ? Give an example.

Answer 21

: A group of tissues working together for a function (e.g., heart).

Question 22

What is an organ system? Give an example.

Answer 22

A group of organs working together (e.g., digestive system).

Question 23

What are the levels of organisation in organisms?

Answer 23

Cell → Tissue → Organ → Organ system → Organism.

Question 24

How do you calculate magnification?

Answer 24

Magnification = Image size ÷ Actual size.

Question 25

What are the units used in biology for size?

Answer 25

1 millimetre (mm) = 1000 micrometres (μm). Use micrometres to measure cells.

Question 26

What is diffusion?

Answer 26

Net movement of molecules from high to low concentration down a concentration gradient due to random motion.

Question 27

What substances move in and out of cells by diffusion?

Answer 27

Oxygen, carbon dioxide, glucose, and waste products.

Question 28

What factors affect the rate of diffusion?

Answer 28

Surface area, temperature, concentration gradient, and distance.

Question 29

What is osmosis?

Answer 29

The diffusion of water molecules from high water potential (dilute) to low water potential (concentrated) through a partially permeable membrane.

Question 30

Define turgid, flaccid, plasmolysis, and turgor pressure.

Answer 30

Turgid: Cell full of water and firm. Flaccid: Cell has lost water and is soft. Plasmolysis: Membrane pulls away from wall after water loss. Turgor pressure: Pressure inside plant cells due to water pushing against the cell wall.

Question 31

: What happens when plant cells are placed in different solutions?

Answer 31

In dilute: become turgid. In concentrated: become plasmolysed. In equal: no net movement.

Question 32

Why is osmosis important in plants and animals?

Answer 32

In plants: maintains turgidity for support. In animals: controls water balance in cells and tissues.

Question 33

What is active transport?

Answer 33

The movement of particles from low to high concentration, against the gradient, using energy from respiration.

Question 34

What are examples of active transport?

Answer 34

Ion uptake by root hair cells. Glucose uptake in villi and kidney tubules.

Question 35

What is needed for active transport to occur?

Answer 35

Protein molecules in the cell membrane and energy (ATP).