Year 9 end of years (Pippas)

Question 1

What is the function of a microscope?

Answer 1

To magnify small objects so they can be seen in detail.

Question 2

What is the formula for magnification?

Answer 2

Magnification = image size / actual size

Question 3

Name three organelles found in both plant and animal cells.

Answer 3

Nucleus, cytoplasm, cell membrane

Question 4

Which structures are found only in plant cells?

Answer 4

Cell wall, chloroplasts, permanent vacuole

Question 5

What is a eukaryotic cell?

Answer 5

A cell with a nucleus enclosed in a membrane.

Question 6

What is a prokaryotic cell?

Answer 6

A cell without a nucleus, like a bacterial cell.

Question 7

What is the function of a sperm cell?

Answer 7

To carry genetic information to the egg.

Question 8

Why do muscle cells contain many mitochondria?

Answer 8

To provide energy for contraction.

Question 9

What is the function of root hair cells?

Answer 9

To absorb water and minerals from the soil.

Question 10

What is the role of xylem cells?

Answer 10

To transport water through the plant.

Question 11

What is diffusion?

Answer 11

The movement of particles from an area of high concentration to low concentration.

Question 12

Name a factor that affects the rate of diffusion.

Answer 12

Temperature, surface area, or concentration gradient.

Question 13

What is osmosis?

Answer 13

The movement of water from a region of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) across a semi- permeable membrane.

Question 14

Does osmosis require energy?

Answer 14

No, it is a passive process.

Question 15

What happens to a plant cell in a dilute solution?

Answer 15

It becomes turgid as water enters.

Question 16

What happens to a plant cell in a concentrated solution?

Answer 16

It becomes plasmolysed as water leaves.

Question 17

What is active transport?

Answer 17

The movement of substances against a concentration gradient using energy.

Question 18

Where does active transport occur in plants?

Answer 18

In root hair cells to absorb minerals.

Question 19

What is mitosis?

Answer 19

Cell division that produces two identical daughter cells.

Question 20

Why is mitosis important?

Answer 20

For growth, repair, and asexual reproduction.

Question 21

What is cell differentiation?

Answer 21

The process by which cells become specialized.

Question 22

When does most differentiation occur in animals?

Answer 22

During early development.

Question 23

What are stem cells?

Answer 23

Undifferentiated cells that can become different types of cells.

Question 24

Where can human stem cells be found?

Answer 24

Embryos and adult bone marrow.

Question 25

What is one ethical issue of embryonic stem cells?

Answer 25

It involves the destruction of embryos.

Question 26

What is a potential benefit of stem cells?

Answer 26

They could be used to treat diseases like diabetes.

Question 28

What are the advantages of an electron microscope over a light microscope?

Answer 28

Electron microscopes have higher resolution and magnification, allowing more detailed images of cell structures.

Question 29

What is resolution in microscopy?

Answer 29

The ability to distinguish between two points; higher resolution gives clearer images.

Question 30

What is the function of the nucleus?

Answer 30

Contains genetic material and controls the activities of the cell.

Question 31

What is the role of the permanent vacuole in plant cells?

Answer 31

Maintains cell turgor and stores cell sap.

Question 32

What structures are found in prokaryotic cells but not in eukaryotic cells?

Answer 32

Plasmids and a single circular strand of DNA.

Question 33

Why are bacteria classified as prokaryotes?

Answer 33

Because their cells do not have a true nucleus or membrane-bound organelles.

Question 34

How is a nerve cell adapted to its function?

Answer 34

Long axon for transmitting signals, branched endings for connections.

Question 35

Why do red blood cells have no nucleus?

Answer 35

To provide more space for haemoglobin to carry oxygen.

Question 36

How is a palisade mesophyll cell adapted for photosynthesis?

Answer 36

Contains many chloroplasts and is positioned at the top of the leaf.

Question 37

Why do xylem cells have lignin in their walls?

Answer 37

To strengthen them and keep them open for water flow.

Question 38

How does surface area affect diffusion?

Answer 38

Larger surface area increases the rate of diffusion.

Question 39

Give an example of diffusion in the human body.

Answer 39

Oxygen diffuses from the alveoli into the blood.

Question 40

What is a partially permeable membrane?

Answer 40

A membrane that allows some molecules (like water) to pass through but not others.

Question 41

What happens to an animal cell in a hypotonic solution?

Answer 41

It swells and may burst due to water entering by osmosis.

Question 42

What is turgor pressure?

Answer 42

The pressure exerted by the cell membrane against the cell wall due to water intake.

Question 43

Why is turgor important for plants?

Answer 43

It keeps stems and leaves rigid and upright.

Question 44

How does active transport differ from diffusion and osmosis?

Answer 44

It requires energy and moves substances against their concentration gradient.

Question 45

Give an example of active transport in animals.

Answer 45

Absorption of glucose in the small intestine.

Question 46

What are the stages of the cell cycle?

Answer 46

Interphase, mitosis, cytokinesis.

Question 47

What happens during interphase?

Answer 47

The cell grows, replicates DNA, and prepares for division.

Question 48

Why is differentiation important?

Answer 48

It allows cells to become specialized for specific functions.

Question 49

Do plant cells retain the ability to differentiate?

Answer 49

Yes, many plant cells can differentiate throughout life.

Question 50

What is one medical use of stem cells?

Answer 50

To treat conditions like spinal cord injuries or replace damaged tissues.

Question 51

What are meristems?

Answer 51

Regions in plants where undifferentiated cells divide and allow growth.

Question 52

What is therapeutic cloning?

Answer 52

Creating an embryo with the same DNA as the patient to produce matching stem cells.

Question 53

What is one concern about using adult stem cells?

Answer 53

They may not differentiate into all cell types as embryonic stem cells can.