Cell Diversity

Question 1

What is a tissue?

Answer 1

It is a group of similar cells that are modified (or adapted) to carry out the same function(s)

Question 2

What is a simple tissue?

Answer 2

Tissue with one cell type

Question 3

What is a complex tissue?

Answer 3

Tissue with more than one cell type

Question 4

List two tissues found in plants?

Answer 4

Vascular and Dermal tissue

Question 5

Whats the function of vascular tissue and give an example

Answer 5

A complex tissue that contains xylem and phloem. Xylem transports water and dissolved minerals throughout the plant and provides support in woody plants and phloem transports food from the leaves to the rest of the plant

Question 6

What is the function of dermal tissue and give an example

Answer 6

Protection and if a cuticle is present, it also prevents water loss from the plant. Example would be epidermis

Question 7

List two tissues found in humans?

Answer 7

Connective tissue and Nervous tissue

Question 8

What is the function of connective tissue and give an example

Answer 8

Joins and supports other body structures eg, blood. Blood consists of red cells, white cells, platelets in plasma.

Question 9

What is the function of nervous tissue?

Answer 9

Nervous tissue is composed of neurons and sends electrical impulses to and from the brain and spinal cord

Question 10

What is tissue culture?

Answer 10

Is the growth of cells in or on a sterile nutrient medium outside an organism

Question 11

How does tissue culture work?

Answer 11

A sample of tissue is removed and grown in a sterile nutrient medium

Question 12

What should be considered in tissue culture?

Answer 12

That no micro-organisms grow in the bio reactor - they release waste products that kill the cells

Question 13

What is required for tissue culture?

Answer 13

Sterile nutrient medium, chemical to enhance growth (hormones), minerals and vitamins and source of energy (glucose)

Question 14

What are two examples of tissue culture?

Answer 14

Micropropagation and cancer research

Question 15

What is micropropagation?

Answer 15

It’s the growth of a large number of plants from very small pieces of that plant, usually cells or tissues. A desirable plant is cut into pieces and is grown or cultured in a lab on a suitable medium. They form a callus. Then the growing conditions are changed so that the callus continue to grow and after some Then it forms a young plant embryo and then a young plant. When they’re sufficiently large they are then planted

Question 16

What are the benefits of micropropagation?

Answer 16

A large number of plants are produced in a short time
The plants grown in this way are genetically identical
It is an inexpensive way to produce large numbers of similar plants

Question 17

How is tissue culture used for cancer research?

Answer 17

Cancer cells produce special antigens that are abnormal. Using tissue culture, it’s possible to produce special antibodies [called monoclonal antibodies] that will react with the antigens on cancer cells.

Question 18

What are the benefits of monoclonal antibodies

Answer 18

They may change colour when they react with cancer antigens. That way we can tell if a sample of cells are cancerous
If toxic drugs are attached to the monoclonal antibodies, the drug is delivered only to cancer cells

Question 19

What is an organ?

Answer 19

It’s a structure composed of a number of tissues that work together to carry out one or more functions

Question 20

Give an example of a plant organ?

Answer 20

A leaf, it contains three types of plant tissue
1) dermal tissue found in the epidermis
2) vascular tissue found in xylem and phloem in vascular bundles
3) ground tissue found in palisade and mesophyll cells
Combine to carry out photosynthesis

Question 21

Give an example of an animal organ

Answer 21

The heart
1) walls of the heart at made of cardiac muscle [muscular tissue]
2) the heart is enclosed in a membrane called the pericardium [epithelial]
3) blood and numerous blood vessels are present [connective tissue]
4) the heart is controlled by nervous tissue
All combined to pump blood

Question 22

What is an organ system?

Answer 22

It consists of a number of organs working together to carry out one or more functions

Question 23

How many organ systems do humans have

Answer 23

10

Question 24

Give two examples of animal organ systems

Answer 24

The circulatory system

The digestive system

Question 25

What is the circulatory system?

Answer 25

It consists of the heart, blood, blood vessels. [also lymph vessels and lymph]. It’s function is to transport materials around the body and to fight infection

Question 26

What is the digestive system?

Answer 26

It consists of the mouth, the oesophagus, the stomach, small intestine, large intestine and anus [in association with pancreas and liver]
It’s functions are to take in food, break it down and transfer the digested food into the circulatory system so that it can carried to all the cells in the body

Question 27

What is biological organisation?

Answer 27

It’s the way in which living things are organised
Cell = tissue = organ = organ system = organism
Red blood cell = blood = heart = circulatory system = organism

Question 28

How is the vascular tissue adapted to carry out it’s function

Answer 28

Xylem for example which transports water, has no cytoplasm or organelles [hollow]

Question 29

How is the nervous tissue adapted to carry out it’s function

Answer 29

Neurons contain long fibres which carry impulses

Question 30

State two requirements for successful tissue culture

Answer 30

Sterile conditions
Nutrients
Hormones
Suitable temp and PH

Question 31

How does an organ differ from a tissue?

Answer 31

Organ is a group of tissues working together