Cell biology

Question 1

What are the two main types of cells?

Answer 1

Prokaryotic and eukaryotic cells.

Question 2

Give an example of a prokaryotic cell.

Answer 2

Bacterial cell.

Question 3

Give examples of eukaryotic cells.

Answer 3

Animal and plant cells.

Question 4

What structures are found in both animal and plant cells?

Answer 4

Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes.

Question 5

What structures are found only in plant cells?

Answer 5

Cell wall, chloroplasts, permanent vacuole.

Question 6

What is the function of the nucleus?

Answer 6

Contains genetic material and controls cell activities.

Question 7

What is the function of mitochondria?

Answer 7

Site of aerobic respiration.

Question 8

Name a specialised cell and its function.

Answer 8

Sperm cell – fertilises the egg.

Question 9

How is a root hair cell adapted to its function?

Answer 9

Long projection increases surface area for water absorption.

Question 10

How is a red blood cell adapted?

Answer 10

No nucleus, biconcave shape, contains haemoglobin.

Question 11

What’s the difference between light and electron microscopes?

Answer 11

Electron microscopes have higher resolution and magnification.

Question 12

What is resolution?

Answer 12

The ability to distinguish between two points.

Question 13

What is magnification?

Answer 13

How much bigger the image is compared to the object.

Question 14

What is the formula for magnification?

Answer 14

Magnification = Image size / Actual size.

Question 15

What is mitosis?

Answer 15

Cell division that produces two identical daughter cells.

Question 16

What is the cell cycle?

Answer 16

Series of stages cells go through to grow and divide.

Question 17

Why is mitosis important?

Answer 17

For growth, repair, and asexual reproduction.

Question 18

What are stem cells?

Answer 18

Undifferentiated cells that can develop into different cell types.

Question 19

Where can stem cells be found?

Answer 19

Embryos and adult bone marrow.

Question 20

What are the ethical issues with embryonic stem cells?

Answer 20

Some believe it is wrong to use embryos for research.

Question 21

What are potential uses of stem cells?

Answer 21

Treating diseases like diabetes or paralysis.

Question 22

What is diffusion?

Answer 22

The movement of particles from high to low concentration.

Question 23

What affects the rate of diffusion?

Answer 23

Concentration gradient, temperature, surface area.

Question 24

What is osmosis?

Answer 24

The diffusion of water across a partially permeable membrane.

Question 25

What is active transport?

Answer 25

The movement of substances against a concentration gradient using energy.

Question 26

How do prokaryotic cells differ from eukaryotic cells?

Answer 26

Prokaryotic cells have no nucleus; their DNA is free in the cytoplasm.

Question 27

What is the size range of a typical prokaryotic cell?

Answer 27

0.1–5 micrometres.

Question 28

What is the size range of a typical eukaryotic cell?

Answer 28

10–100 micrometres.

Question 29

Do prokaryotic cells contain membrane-bound organelles?

Answer 29

No, only eukaryotic cells do.

Question 30

What structures are commonly found in bacterial cells?

Answer 30

Cell wall, cell membrane, cytoplasm, plasmid DNA, single circular DNA strand.

Question 31

What is the function of the cytoplasm?

Answer 31

It is where most chemical reactions take place.

Question 32

What is the function of ribosomes?

Answer 32

They are the site of protein synthesis.

Question 33

What is the role of the cell wall in plant cells?

Answer 33

It strengthens the cell and provides support.

Question 34

What does the permanent vacuole do in plant cells?

Answer 34

It contains cell sap and helps maintain pressure inside the cell.

Question 35

What is the role of chloroplasts in plant cells?

Answer 35

They absorb light energy for photosynthesis.

Question 36

Which part of the cell controls what enters and leaves?

Answer 36

The cell membrane.

Question 37

What is cell differentiation?

Answer 37

The process by which cells become specialised for a specific function.

Question 38

When does most differentiation occur in animals?

Answer 38

During early development (embryonic stage).

Question 39

Why are nerve cells long and thin?

Answer 39

To transmit electrical signals over long distances.

Question 40

What are ciliated epithelial cells specialised for?

Answer 40

Moving mucus and trapped particles out of the respiratory tract.

Question 41

Why do muscle cells contain many mitochondria?

Answer 41

To release energy for contraction.

Question 42

Why are electron microscopes useful in biology?

Answer 42

They allow scientists to see organelles in much greater detail.

Question 43

What is the maximum magnification of a light microscope?

Answer 43

Around ×1500.

Question 44

What is the maximum magnification of an electron microscope?

Answer 44

Over ×1,000,000.

Question 45

What type of microscope is used to observe living cells?

Answer 45

Light microscope.

Question 46

How do you calculate actual size from image size and magnification?

Answer 46

Actual size = Image size ÷ Magnification.

Question 47

Why is staining used in microscopy?

Answer 47

To highlight different parts of cells for clearer observation.

Question 48

What happens during interphase?

Answer 48

The cell grows, replicates DNA and prepares for division.

Question 49

What are the stages of mitosis in order?

Answer 49

Prophase, metaphase, anaphase, telophase.

Question 50

What is cytokinesis?

Answer 50

Division of the cytoplasm to form two separate cells.

Question 51

What is produced at the end of mitosis?

Answer 51

Two genetically identical daughter cells.

Question 52

What type of cells does mitosis occur in?

Answer 52

Body cells (somatic cells).

Question 53

How is cancer related to mitosis?

Answer 53

Uncontrolled cell division can lead to tumour formation.

Question 54

What is the main advantage of embryonic stem cells?

Answer 54

They can differentiate into all cell types (totipotent).

Question 55

Why are adult stem cells more limited?

Answer 55

They can usually only form certain types of cells.

Question 56

Where are adult stem cells found?

Answer 56

Bone marrow, skin, and other tissues.

Question 57

What is therapeutic cloning?

Answer 57

Creating an embryo with the same DNA as the patient to grow compatible tissues.

Question 58

Why might stem cell therapy be risky?

Answer 58

It could transfer viral infections or cause immune rejection.

Question 59

How are plant stem cells useful?

Answer 59

They can clone rare species and create disease-resistant plants.

Question 60

What is a concentration gradient?

Answer 60

The difference in concentration between two areas.

Question 61

Why is diffusion important in cells?

Answer 61

It allows substances like oxygen and carbon dioxide to move in and out.

Question 62

What is an example of osmosis in plants?

Answer 62

Water moving into root hair cells from the soil.

Question 63

Why do cells need active transport?

Answer 63

To absorb substances like minerals against a concentration gradient.

Question 64

What energy source is used for active transport?

Answer 64

Energy from respiration (ATP).

Question 65

Give an example of active transport in animals.

Answer 65

Glucose absorption in the small intestine.

Question 66

What factors increase the efficiency of exchange surfaces?

Answer 66

Large surface area, thin membrane, good blood supply, and ventilation (in animals).