Chapter 11 Flashcards
Describe the Hierarchy of structures. from starting with atoms (2 marks)
Atoms -> Molecules -> Organelles-> Cells
State one disadvantage of Prokaryotic cells (2 marks)
Small number of metabolic processes can take place at a given time
State an advantage of unicellular organisms (2 marks)
Unicellular organisms have high surface area to volume ratios allowing cellular processes to occur efficiently
State the 3 factors which lead to unicellular organisms evolving to multicellular organisms (3 marks)
Ability to divide
Specialise
Communicate with other cells
DO WE NEED TO KNOW STRUCTURE OF PARAMECIUM?
Define differentiation (3 marks)
Process by which an unspecialised cell becomes specialised in structure and function occurring at the embryonic development or multicellular organisms
Define specialisation (2 marks)
(of cells) Possession of specific features that relate to a certain role
Define stem cell (2 marks)
Unspecialised cells capable of giving rise to different kinds of specialised, differentiated cells
Name and explain 3 ways stem cells are different from other cells (6 marks)
- they are unspecialised - they have not yet specialised into a particular type of cell
- they have the potential to divide and replicate
- Can differentiate to form different specialised cells
All cells in a multicellular organism contain the same genetic information, but the structures and function of specialised cells differs, outline how this is possible (3 marks)
This is possible as despite all multicellular organisms containing the same genetic information, only a particular set of genes are activated which is dependant on the cell’s immediate environment
Describe the advantages and disadvantages of cell becoming specialised (4 marks)
- Requires communication and coordination between cells
- Specialised cells are dependant completely on other cells to perform activities they cannot
- e.g. Nerve’s carry impulses but rely on red blood cells to bring them oxygen
- If a specialised cell is isolated from its organism, unlike a unicellular organism, it cannot function on it’s own and dies
Outline the hierarchy of structure from cells
Cells -> tissues -> organs -> systems -> multicellular organisms
Name and describe the 4 types of tissues in animals (8 marks)
Connective tissue - Basic tissue type in complex animals which provides strength support and elasticity. it holds certain body parts together examples include bone, ligaments tendons, blood, and cartilage.
Epithelial tissue - Basic tissue type in complex animals which covers many surfaces in the body. including surface of the body, linings of cavities and airways. Also acts as a barrier against infections and water loss
Nervous tissue - Basic tissue type in complex animals which provides a means of communication between all body structures including neuron’s
Muscle tissue - A basic tissue type in animals which is made of thin fibre like threads called muscle fibres which use ATP to perform movements. The fibres are capable of contracting when stimulated by nerve impulses
Define vascular
Describes vessels that conduct fluid
Describe the two systems which organs in vascular plants are grouped into (4 marks)`
Root system - Consists of all systems below the ground. Responsible for absorbing water and nutrients from the soil
Shoot system - All parts of the plant above the ground.
Responsible for
- reproduction
-photosynthesis
-absorption of CO2 and O2
- Support plant growth physically
Describe the 4 main types of tissues in vascular plants and briefly explain each (4 marks)
Dermal - Protects plant from cuts, water loss and invasion by microorganisms.
Vascular - Involved in bulk transport of water, nutrients, sugars and other substances comprising the xylem and phloem
Meristematic - Divide actively to form specialised structures to increase width and length
Ground - all internal cells which aren’t vascular which is involved in storage support and photosynthesis e.g. flesh of apples and pears
