Nature & variety of life Flashcards
)What is the mnemonic for life processes?
MRS GRENC
What does M stand for?
Movement = the ability to move from 1 place to another
What does the first R stand for?
respiration = a chemical reaction between oxygen and glucose that releases energy in all cells
What does the S stand for?
Sensitivity = the ability for an organism to react to an external stimulus
What does the G stand for?
Growth = the increase in size of an organism over a period of time, such as increase in mass or height or increase in number of cells by dividing cells by mitosis
What does the second R stand for?
Reproduction = the production of offspring
What does the E stand for?
Excretion = The removal of waste produced by the body (e.g sweat, urea)
What does the N stand for?
Nutrition = the ability of an organism to obtain food substances to use for carrying out the other life processes
What does the C stand for?
Control = the ability for an organism to regulate its internal conditions eg body temperature
What are the levels of organisation?
Organelles, cells, tissues, organs, organ systems, organisms
What is the function of the nucleus?
Contains genetic information of the cell so therefore controls what happens inside it
What is the function of the mitochondria?
Site of respiration in cells
What is the function of the cell membrane?
Controls what enters and exits the cell
What is the function of ribosomes?
Site of protein synthesis
What is the function of the vacuole?
A space within the cytoplasm that contains cellular sap + helps maintain the structure of the cell
What is the function of the chloroplast?
Contains chlorophyll and is the site of photosynthesis
What is the function of the cell wall?
Rigid wall made of cellulose that provides cell structure and resists changes in pressure within the cell
What is a prokaryotic cell?
- Cell with no nucleus nor any other membrane bound organelles
- they are often found in unicellular organisms such as bacteria
What is a eukaryotic cell?
- eukaryotic cell = cells that contain a nucleus and other membrane bound organelles
- often found in multicellular organisms
How to calculate image size?
Actual size x magnification
How do you calculate actual size?
Image size / magnification
How do you calculate magnification?
Image size/actual size
How many micrometers in a millimetre?
1000
How many micrometers in a centimetre?
10,000
How many micrometers in a meter?
1,000,000
How to convert very small numbers into standard form?
Make the number between 1 and 10 inclusive and then multiply by a negative power of ten.
How to convert very large numbers into standard form?
Make the number between 1 and 10 inclusive and then multiply by a positive power of 10
What is the function of the cytoplasm?
Where most chemical reactions occur
plant examples
Maize, peas, beans
animal examples
Mammals, mosquitos, houseflies
protoctist examples
- amoeba = shares features of an animal cell + lives in pond water
- chlorella = shares features of a plant cell + contains chloroplasts
- plasmodium = a pathogenic protoctist that causes malaria
Pathogen
An organism that causes disease. These include fungi, viruses, bacteria and protoctists