Chapter 6 - Levels of organisation Flashcards
Name the levels of organisation, least complex to most complex
- Chemical and molecular
- Organelle level
- Cellular level
- Tissue level
- Organ levels
- Organ systems
- Organism
Describe the chemical and molecular level
- Most basic level of organisation
- Includes all essential chemicals of life
- Ex. Water, glucose, fats
Describe the organelle level
- Many molecules form complex, highly specialised structures
Describe the cellular level
- Most basic unit of life
- Each type of cell has a different structure and function
Describe the tissue level
Many similar cell working together to perform a specific function
Describe the organ level
- Groups of different tissue layers working together to perform a specific function
- Consists of two or more layers of tissue
Describe an organ system
Group of organs performing closely related functions
Describe an organism
Complex, functioning whole that is the sum of all its component parts
Name two parts of the human body in which ciliated epithelial cells could be found
Trachea and fallopian tubes
State two functions of the cilia on ciliated epithelial cells
- Sweep out dust an bacteria
- Sweep egg cell along fallopian tube
Suggest why ciliated epithelial cells have a high amount of
mitochondria
To release sufficient energy for the cilia to beat
State the function of mucus produced by goblet cells
To trap dust and bacteria
Name two functions of root hair cells
- Absorb minerals, vitamins and water
- Anchor the plant in soil
Suggest why root hair cells are present in large numbers
To maximise surface area for the absorbtion of nutrients and water from the soil
State why root hair cells have long extentions
To maximise surface area for the absorbtion of nutrients and water from the soil
Suggest why root hair cells have many mitochondria
Root hair cells have to carry out active transport and therefore needs large amounts of energy
Give a reason for the fact that root hair cells have large vacuoles
Large vacuoles helps to carry out the process of osmosis
How does movement occur in muscle cells?
The cells have the ability to slide past each other
State where muscle cells are found, and of what they are composed
- Found in voluntary muscles
- Made up of long muscle fiber cells and contractile proteins
State the main function of a motor neuron cell
- Tranmits impulses from the central nervous system to effectors
Name the function of the myelin sheath in a motor neuron cell
Insulates the axon to prevent leakages of the impulse and also speed up the impulse
Name the function of the nodes of Ranvier
Speed up the impulse
Which component of a motor neuron cell produces the mylein sheath?
Schwann cells
Describe how the structure of red blood cells contribute to their function
- 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
Suggest why red blood cells are adapted in such a way that their SA:V ratio is so large
To maximise the amount of oxygen the cell is able to absorb and ensure that haemoglobin is never far from the surface
State where palisade mesophyll cells are found
In leaves just under the upper epidermis
Name one function of palisade mesophyll cells
Photosynthesis
Describe how the structure and location of palisade mesophyll cells contribute to their function
- 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
Everybody wants to change the world,
everybody wants to change the world
But no-one, no-one wants to die!
State where xylem is found
Vascular bundles of roots, stems and leaves
Name two funtions of xylem cells
- Transport water and mineral ions in plants
- Provide support to plants
Describe how the structure and location of xylem cells contribute to their function
- 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
State where sperm cells are found
Epididymis
Name one function of spermatozoa
Fertilises ovum
Describe how the structure of spermatozoa contribute to their function
- 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
Name the two tissue layers found in diploblastic organisms
- Endoderm
- Ectoderm
State why diploblastic organisms are less advanced
They can not develop organs
Give one word for animals that can not develop a body cavity
Acoelomates
Name the three layers of tissue found in the blastula of triploblastic organisms and also name the body cavity
- Ectoderm
- Mesoderm
- Endoderm
- Body cavity is known as coelom
Name four advantages the coelom gives a triploblastic animal
- 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
