Chapter 6 - Levels of organisation

Question 1

Name the levels of organisation, least complex to most complex

Answer 1

1. Chemical and molecular
2. Organelle level
3. Cellular level
4. Tissue level
5. Organ levels
6. Organ systems
7. Organism

Question 2

Describe the chemical and molecular level

Answer 2

• Most basic level of organisation
• Includes all essential chemicals of life
• Ex. Water, glucose, fats

Question 3

Describe the organelle level

Answer 3

• Many molecules form complex, highly specialised structures

Question 4

Describe the cellular level

Answer 4

• Most basic unit of life

- Each type of cell has a different structure and function

Question 5

Describe the tissue level

Answer 5

Many similar cell working together to perform a specific function

Question 6

Describe the organ level

Answer 6

• Groups of different tissue layers working together to perform a specific function
• Consists of two or more layers of tissue

Question 7

Describe an organ system

Answer 7

Group of organs performing closely related functions

Question 8

Describe an organism

Answer 8

Complex, functioning whole that is the sum of all its component parts

Question 9

Name two parts of the human body in which ciliated epithelial cells could be found

Answer 9

Trachea and fallopian tubes

Question 10

State two functions of the cilia on ciliated epithelial cells

Answer 10

• Sweep out dust an bacteria

- Sweep egg cell along fallopian tube

Question 11

Suggest why ciliated epithelial cells have a high amount of

mitochondria

Answer 11

To release sufficient energy for the cilia to beat

Question 12

State the function of mucus produced by goblet cells

Answer 12

To trap dust and bacteria

Question 13

Name two functions of root hair cells

Answer 13

• Absorb minerals, vitamins and water

- Anchor the plant in soil

Question 14

Suggest why root hair cells are present in large numbers

Answer 14

To maximise surface area for the absorbtion of nutrients and water from the soil

Question 15

State why root hair cells have long extentions

Answer 15

To maximise surface area for the absorbtion of nutrients and water from the soil

Question 16

Suggest why root hair cells have many mitochondria

Answer 16

Root hair cells have to carry out active transport and therefore needs large amounts of energy

Question 17

Give a reason for the fact that root hair cells have large vacuoles

Answer 17

Large vacuoles helps to carry out the process of osmosis

Question 18

How does movement occur in muscle cells?

Answer 18

The cells have the ability to slide past each other

Question 19

State where muscle cells are found, and of what they are composed

Answer 19

• Found in voluntary muscles

- Made up of long muscle fiber cells and contractile proteins

Question 20

State the main function of a motor neuron cell

Answer 20

• Tranmits impulses from the central nervous system to effectors

Question 21

Name the function of the myelin sheath in a motor neuron cell

Answer 21

Insulates the axon to prevent leakages of the impulse and also speed up the impulse

Question 22

Name the function of the nodes of Ranvier

Answer 22

Speed up the impulse

Question 23

Which component of a motor neuron cell produces the mylein sheath?

Answer 23

Schwann cells

Question 24

Describe how the structure of red blood cells contribute to their function

Answer 24

• Transport oxygen as oxyhaemoglobin
• Smallest cells to be pumped through capillaries
• Contain haemoglobin
• Elastic to be squeezed through capillaries
• No nucleus to maximise the amount of oxygen the cell can carry
• No mitochondria to prevent the usage of oxygen during transport
• Biconcave to maximise surface area relative to volume
• Large surface area:volume ratio

Question 25

Suggest why red blood cells are adapted in such a way that their SA:V ratio is so large

Answer 25

To maximise the amount of oxygen the cell is able to absorb and ensure that haemoglobin is never far from the surface

Question 26

State where palisade mesophyll cells are found

Answer 26

In leaves just under the upper epidermis

Question 27

Name one function of palisade mesophyll cells

Answer 27

Photosynthesis

Question 28

Describe how the structure and location of palisade mesophyll cells contribute to their function

Answer 28

- Contain chloroplasts with chlorophyll to trap maximum light for photosynthesis - Long and cylindrical so more can fit into a leaf - Cell walls are thin for easy gaseous exchange by diffusion - At right angles to the upper epidermis to trap maximum light

Question 29

Everybody wants to change the world, | everybody wants to change the world

Answer 29

But no-one, no-one wants to die!

Question 30

State where xylem is found

Answer 30

Vascular bundles of roots, stems and leaves

Question 31

Name two funtions of xylem cells

Answer 31

- Transport water and mineral ions in plants | - Provide support to plants

Question 32

Describe how the structure and location of xylem cells contribute to their function

Answer 32

- Long hollow tubes connected end to end to form a long continuous column - To end walls to form tubes - No cytoplasm or organelles so there is no obstruction to the flow of water and mineral ions - Lignified walls to strengthen and prevent collapse - supports plant - Unlignified areas called pits for lateral movement of water

Question 33

State where sperm cells are found

Answer 33

Epididymis

Question 34

Name one function of spermatozoa

Answer 34

Fertilises ovum

Question 35

Describe how the structure of spermatozoa contribute to their function

Answer 35

- Head has a haploid nucleus which fuses with haploid nucleus of ovum to form a diploid zygote - Head has an acrosome which contains hydrolytic enzymes to digest a path into the egg cell - Middle piece contains many mitochondria to release energy for the tail to beat - The tail has an axial filament which causes the beating of the tail

Question 36

Name the two tissue layers found in diploblastic organisms

Answer 36

- Endoderm | - Ectoderm

Question 37

State why diploblastic organisms are less advanced

Answer 37

They can not develop organs

Question 38

Give one word for animals that can not develop a body cavity

Answer 38

Acoelomates

Question 39

Name the three layers of tissue found in the blastula of triploblastic organisms and also name the body cavity

Answer 39

- Ectoderm - Mesoderm - Endoderm - Body cavity is known as coelom

Question 40

Name four advantages the coelom gives a triploblastic animal

Answer 40

- Allows the animal to become larger and more complex by providing space to develop organs - Allows the body wall and organs to function independently - In some organisms the coelom is filled with a fluid which acts as a hydrostatic skeleton - The coelomic fluid transports oxygen, nutrients and waste