Cell Structure

Question 1

Function of Nucleus

Answer 1

Contains genetic material (chromosomes)

Question 2

Function of cytoplasm

Answer 2

Site of many chemical reactions
Contains water and many solutes

Question 3

Function of cell membrane

Answer 3

Controls substances entering and leaving the cell

Question 4

Function of cell wall

Answer 4

Gives the cell extra support and defines its shape, prevents bursting

Question 5

Function of mitochondria

Answer 5

Site of aerobic respiration, providing energy for the cell

Question 6

Function of Chloroplasts

Answer 6

Site of photosynthesis
Contains chlorophyll to absorb light for photosynthesis

Question 7

Function of ribosomes

Answer 7

Site of protein synthesis

Question 8

Funciton of Vacuole

Answer 8

Contains cell sap (water with dissolved solutes)
Pushes the cytoplasm against the cell wall, keeping the cell turgid

Question 9

What is cell differentiation?

Answer 9

The process by which a cell becomes specialised

Question 10

Why is cell differentiation important?

Answer 10

It allows cells to develop structures needed to perform specific functions.

Question 11

What are specialised cells?

Answer 11

Cells that have developed specific characteristics to carry out particular functions.

Question 12

What controls cell differentiation?

Answer 12

Genes in the nucleus.

Question 13

What happens during differentiation?

Answer 13

The cell changes its structure and subcellular composition.

Question 14

When does differentiation occur?

Answer 14

As an organism develops.

Question 15

Example: How does a nerve cell form?

Answer 15

The cytoplasm and cell membrane elongate to make long-distance connections.

Question 16

What are stem cells?

Answer 16

Undifferentiated cells that can divide by mitosis to form more stem cells or specialised cells (an unlimited number of times)

Question 17

What happens as a multicellular organism develops?

Answer 17

Its cells differentiate to form specialised cells.

Question 18

When do most animal cells differentiate?

Answer 18

At an early stage of development.

Question 19

What happens to animal cells after early development?

Answer 19

They lose the ability to differentiate.

Question 20

What are adult stem cells?

Answer 20

Undifferentiated cells in specific body locations that can differentiate into a limited number of specialised cell types.

Question 21

What do adult stem cells do?

Answer 21

Replace and repair cells like blood and skin cells.

Question 22

How do plant cells differ from animal cells in differentiation?

Answer 22

Many plant cells retain the ability to fully differentiate throughout life.

Question 23

What are embryonic stem cells?

Answer 23

Stem cells from embryos that can differentiate into any type of cell in the body.

Question 24

What do ciliated cells do?

Answer 24

They have cilia (extensions of the cell membrane) that beat to transport mucus and trapped particles toward the throat.

Question 25

How are ciliated cells adapted?

Answer 25

They have cilia. Lots of mitchondria due to high energy use.

Question 26

What do nerve cells do?

Answer 26

Conduct impulses and allow communication between body parts and the central nervous system.

Question 27

How are nerve cells adapted?

Answer 27

They are long and have axons covered in a fatty myelin sheath to speed up transmission.

Question 28

What do red blood cells do?

Answer 28

Transport oxygen efficiently.

Question 29

How are red blood cells adapted?

Answer 29

Biconcave disk shape for high SA:VR. Also so it can squeeze through tight gaps. Packed with haemoglobin, and no nucleus to maximise space

Question 30

What do root hair cells do?

Answer 30

Absorb water and mineral ions from the soil.

Question 31

How are root hair cells adapted?

Answer 31

Long extensions for SA:VR and thin walls for fast water movement. Lots of mitochondria (energy needed for active transport)

Question 32

What do palisade mesophyll cells do?

Answer 32

Carry out photosynthesis in the leaf.

Question 33

How are palisade mesophyll cells adapted?

Answer 33

Contain many chloroplasts, are column-shaped, and tightly packed to maximise light absorption, large vacuole to store water for photosynthesis.

Question 34

Where are adult stem cells found

Answer 34

Some tissues and organs such as bone marrow

Question 35

How does DNA control cell differentiation?

Answer 35

By switching specific genes on or off, which leads to production of proteins that shape the cell’s structure and function.

Question 36

Why are stem cells interesting in medicine?

Answer 36

Because they can be used to grow new tissues, repair damaged organs, and potentially treat diseases like diabetes and paralysis by differentiating into specialised cells.

Question 37

What is therapeutic cloning?

Answer 37

A technique where an embryo is created using a patient’s DNA to produce stem cells that can be used to treat disease without immune rejection.

Question 38

Why are stem cells from therapeutic cloning useful in medicine?

Answer 38

They are genetically identical to the patient, so they are not rejected and can be used for treatment without immune suppression drugs.

Question 39

What are the ethical concerns about using embryonic stem cells?

Answer 39

Each one has the potential to be a human life