What type of cells are animal and plant cells and what is typically contained in them
Plant and animal cells (eukaryotic cells) have a cell membrane, cytoplasm and genetic material enclosed in a nucleus.
What type of cells are prokaryotic cells and what are the differences with eukaryotic cells
Bacterial cells (prokaryotic cells) are much smaller in comparison. They have cytoplasm and a cell membrane surrounded by a cell wall. The genetic material is not enclosed in a nucleus. It is a single DNA loop and there may be one or more small rings of DNA called plasmids
What are the differences between sizes centi,nano,milli,micro
centi c 0.01 × 10-2
milli m 0.001 × 10-3
micro μ 0.000,001 × 10-6
nano n 0.000,000,001 × 10-9
What organelles do most animal cells have
a nucleus
* cytoplasm
* a cell membrane
* mitochondria
* ribosomes.
What do plant cells have that animal cells do not have
chloroplasts
* a permanent vacuole filled with cell sap.
Plant and algal cells also have a cell wall made of cellulose, which strengthens the cell.
Give 3 examples of specialised cells including at least 1 plant + animal cell
sperm cells, nerve cells and muscle cells in animals
* root hair cells, xylem and phloem cells in plants.
Why are differentiated cells important
Differentiated cells are important in a multicellular organism because they are able to perform a specialised function in the body
When do animal cells differentiate
early stage of life
When do plant cells differentiate
Many types of plant cells retain the ability to differentiate throughout life.
Describe the food test practical
First take the food sample and grind this with distilled water using a mortar and pestle we want to make a paste second transfer the paste to beaker and add more distilled water. Stir so the chemicals in the food dissolve in the water then filter the solution to remove suspended food particles.
Describe how to test for starch
First place 2cm^3 of food solution in a test tube next add a few drops of iodine solution (orange) if starch is present then solution turns blue black if not it stays orange.
Describe how to test for sugars
start w 2cm cubed in test tube then add 10 drops of Benedictus solution (blue) place test tube into beaker and half fill beaker with hot water via kettle, leave for 5 mins if sugars are present colour changes green = small sugar yellow = more than green brick red= lotta sugar
this test only works for certain reducing sugars like glucose but won’t work for non reducing eg sucrose
How to test for protein
Cubed of food solution and add 2 cm³ of buret solution (blue) if protein is present solution turns to purple/lillac
How to test for lips/ fats
unlike other tests you do not filter solution when testing for lips cause lipids stick first add normal amount of food and add a few drops of distilled water and ethanol. Your should then gently shake if lips are present cloudy emulsion forms.
What is diffusion
Diffusion is the net movement of particles from a high to low concentration down a concentration gradient
Describe active transport
Active transport of substances from Waterloo solution to a more concentrated solution (against a concentration gradient) requires energy from respiration
Give an example of active transport in animals
The LUMEN: takes in sugars when digesting in small intestine and moves them into the bloodstream
Give an example of active transport in plants
Root hair cell: Active transport is used to move ions into the cells which are then moved into the xylem
What are arteries and description of them.
Arteries carry very high pressure blood from the heart to the organs in the body they have very thick muscular walls which allows them to a standard very high pressure of the blood blood trouble through the arteries in surges every time the heart beats. To cope with this there elastic fibres which stretch with a surge of blood passes through them and then recoil in between surgeries which keeps the blood moving.
What are capillaries
Found in organs
when the blood passes through capillaries substances such as glucose and oxygen diffuse from the blood the cells and carbon dioxide diffuses from the cells back to the blood. capillaries have very thin walls which means the diffusion pathway is very short this allows substances to diffuse rapidly between the blood and the body cells.
What are veins
Blood makes its way back to the heart after the organs in veins.
The blood is now travelling slowly and at a low pressure this means it could stop or even go backwards. Veins have a thin wall. the blood pressure is low so the wall does not need to be thick. Many veins contain valves the job valves is to stop blood flowing backwards. When the blood is flowing in the correct direction the valves open to allow the blood to flow through. But the minute the blood starts to flow backwards the valves shut.
What are enzymes and what do they do
Enzymes catalyse speed up chemical reactions.
enzymes are large protein molecules and they have a groove on their surface called the active site
When an enzyme fits with a substrate it breaks it down into the products
What are the typical symptoms of measles and are they bacteria
The red rash and a temperature
No they are a virus
What type of pathogen is malaria and what are the symptoms
Protists sent by vectors (mainly mosquitos ), and they get fevers that can be fatal
