Biology Topic 1 main-cells

Created by

Oisin Braniff

Cards (35)

What is function of cell membrane
Selectively permeable so controls what enters and leaves the cell
function of vacuole  
Contains cell sap, makes cell rigid and provides support
Function of cell wall
Stiff structure which provides support
Function of cytoplasm  
Chemical reactions take place here
Function of mitochondria  
Chemical reactions of cell respiration take place here
Function of nucleus 
Control centre of cell and contains genetic information such as DNA
Function of Chloroplasts  
Contains chlorophyll which traps light for sun and makes its own food through photosynthesis
What are forceps used for
To peel the thin transparent layer of epidermis cells from the inside section of a small onion leaf
Why are coverslips lowered onto slide one end first
To prevent trapping air bubbles
Why should u use a low objective lens power first
Wider FOV and allows us to see more cells
What is resolution  
The ability of a microscope to let us see detail
What is an advantage of electron microscopes
Allow us to see cell ultrastructure
what substances do cells need
Oxygen mineral ions water dissolved food molecules
How do substances move into the cell
By diffusion
What is diffusion 
The random movement of molecules from an area of high concentration to an area of low concentration
what are the 3 factors that affect rate of diffusion
Temperature- higher temp means molecules have more kinetic energy to move around, increasing rate
Surface area- the larger the surface area, the faster the rate
Concentration gradient-Difference in concentration between high and low concentration areas. Larger difference=faster rate
Effect of surface area and Volume
Higher volume=more oxygen needed for reactions
Higher surface area=more oxygen that can diffuse into cell
What have multi celled organisms developed to increase SA
Gas exchange surfaces in their lungs
What is the importance of a transport system
the gas exchange surface is often far away from other body cellsb
what are tissues 
A group of similar cells that work together to carry out a particular function
What are organs 
A group of different cells that work together to carry out a particular function eg stomach liver
What are organ systems  
A group of organ systems that work together to carry out a particular function eg digestive and reproductive system
What are stem cells  
Unspecialised cells that can turn into any type of blood cell
What are stem cells two important abilities
To continue dividing by cell division to produce more blood cells
to differentiate into a wide variety of stem cell types
Where can stem cells be collected
Embryos, umbilical cord placenta
What about stem cells in adult animals
They have changed permanently into specialised cells and lost their ability to divide further
Where are adult animal stem cells found
Bone marrow
Where are stem cells in plants found
Meristems at ends of shoots and roots
Describe the stem cells in plants in terms of division
They retain the ability to divide until they are in their final position in root,leaf or stem. Under certain conditions specialisation can be reversed
What is leukaemia  
Treatment of the cancer of the white blood cells
Why Do u get leukaemia
White blood cells in bone marrow function abnormally and lost the ability to fight disease
What is the first stage of leukaemia treatment
Use of chemotherapy and radiotherapy to kill the cancerous white blood cells in patients body
What happens if transplant of stem cells is successful
The stem cells will multiply and produce healthy blood cells in patient
What are the 2 risks with this type of treatment
•use of chemotherapy and radiotherapy can leave patient with no immune system and at risk of infection
•stem cells can divide in an uncontrolled manner and produce unwanted tumours
What are the ethical issues with this  
It necessitates the destruction of embryos