Levels of Organisation and Cell Structure

Question 1

What are the levels of organisation in order?

Answer 1

• Organelles
• Cells
• Tissues
• Organs
• Organ Systems
• Organisms

Question 2

What are organelles?

Answer 2

A component within a cell that carries out a specific function

Examples include chloroplasts and mitochondria

Question 3

What are cells?

Answer 3

Basic functional and structural units in a living organism

• They make up a whole unicellular organism
• Examples include palisade mesophyll cells and sperm cells

Question 4

What are tissues?

Answer 4

A group of cells of similar structure working together to perform a particular function

Examples include xylem and muscle

Question 5

What are organs?

Answer 5

Made from a group of different tissues working together to perform a particular function

Examples include the heart and a leaf

Question 6

What are organ systems?

Answer 6

Made from a group of organs with related functions working together to perform bodily functions within the organism

Examples include the digestive system and the root system

Question 7

Which organelles are in every eukaryotic organism?

Answer 7

• Nucleus
• Mitochondria
• Ribosomes
• Cytoplasm
• Cell Membrane

Question 8

Which organelles do plant cells have which animals cell do not have?

Answer 8

• Chloroplasts (containing chlorophyll)
• Permanent vacuole
• Cell wall

Question 9

What is the function of the nucleus?

Answer 9

It contains the genetic material of the cell which controls how the cell grows and works, like cell divison

Question 10

What is the function of the cytoplasm?

Answer 10

• The gel like fluid is the site of most chemical reactions in the cell (like anaerobic respiration)
• Provides a platform for organelles, allowing them to function and protecting them

Question 11

What is the function of the cell membrane?

Answer 11

• Holds the cell together
• Controls which substances enter and leave the cell as it is selectively permeable

Question 12

What is the function of the cell wall?

Answer 12

Gives the cell extra support and defines its shape

Question 13

What is the function of chloroplasts?

Answer 13

• They are the site of photosynthesis, providing food for plants
• Contains chloropyll, which absorb light energy

Question 14

What is the function of the permanent vacuole?

Answer 14

• Helps support the shape of the cell
• Storage of water and other materials, like cell sap

Question 15

What is the function of mitochondria?

Answer 15

• It is the site of aerobic respiration
• Cells needing more energy will have more mitochondria

Question 16

What is the function of ribosomes?

Answer 16

They are the site of protein synthesis

Question 17

What is a specialised cell?

Answer 17

A cell within an organism which has adapted to perform a specific function through developing a different strucure and composition of subcellular structures (differentiation)

• Each cell in an organism will have the same genetic information, but only some of it will be used
• Examples include a sperm cell or a root hair cell

Question 18

What are undifferentiated cells called?

Answer 18

Stem cells

Question 19

When does most differentiation happen in animals?

Answer 19

When they are an embyro, although adult stem cells do exist in places such as the bone marrow

Question 20

When does differentiation happen in plants and where do the stem cells come from?

Answer 20

Throughout their whole life via meristem tissue

Question 21

How can stem cells be used in medicine?

Answer 21

• To grow new tissue and repair broken organs
• It can treat autoimmune diseases like diabetes

Question 22

Why must an embryo grown through therapeutic cloning be used?

Answer 22

So that the stem cells are not rejected by the patients body

Question 23

What are the benefits of using stem cells in medicine?

Answer 23

• Can treat a variety of diseases like diabetes
• Embyros grown through therapeutic cloning will produce stem cells which will not be rejected, like it does for organs which are donated

Question 24

What are the medical risks associated with stem cell treatment?

Answer 24

• A virus could be transmitted from the stem cell cultured in the lab to the patient
• The cultured stem cell could develop mutations and become cancerous

Question 25

What are the ethical issues with stem cell treatment?

Answer 25

• There is no saying who owns the embyro and who has rights over it
• Is it right to clone (playing god)?
• Should an embryo be treated as a person or not and is it truly alive?