organisms Flashcards
What are the 8 characteristics of living organisms? (MRS H GREN)
movement, reproduction, sensitivity, homeostasis, growth, respiration, excretion, nutrition
What are organelles?
Tiny structures within cells, eg nucleus, cell membrane, cytoplasm
What organelles do plant cells have?
Same as animal cells plus: chloroplasts, cell wall, vacuole
What are tissues?
Group of similar cells that have a similar function eg muscle tissue (animals), xylem tissue (plants)
What is an organ?
Group of tissues that work together to carry out function eg lungs (mammals) or leaves (plants)
What is an organ system?
Organs work together to form organ systems eg digestive system includes stomach, intestines, pancreas, liver
What are the common features of plants?
- Multicellular
- Have chloroplasts, so can photosynthesise
- Cells have cell walls, made of cellulose
- Store carbohydrates as sucrose or starch
- Examples: cereals, herbaceous legumes (peas etc)
What are the common features of animals?
- Multicellular
- Don’t have chloroplasts, can’t photosynthesise
- Cells don’t have cell walls
- Most have some kind of nervous co-ordination (respond rapidly to changes in their environment)
- Can usually move around
- Often store carbohydrate in the form of glycogen
- Examples: mammals, insects
What are the common features of fungi?
- Some are single-celled
- Others have a body called a mycelium, made up of hyphae (thread-like structures)
- Can’t photosynthesise
- Cells have cell walls made of chitin
- Most feed by saprotropic nutrition – dissolve food with enzymes, then absorb nutrients
- Can store carbohydrate as glycogen
- Examples: yeast, mucor
What are the features of proctotists?
- Single celled and microscopic
- Some have chloroplasts and are similar to plant cells
- Others more like animal cells
- Examples: chlorella, amoeba
What are the features of bacteria?
- Single celled and microscopic
- Don’t have a nucleus
- Have a circular chromosome of DNA
- Some can photosynthesise
- Most feed off other organisms, living and dead
- Examples: lactobacillus bulgaricus, pneumococcus
What are the features of viruses?
- Particles rather than cells, smaller than bacteria
- Can only reproduce inside living cells
- Infect all types of living organisms
- Come in lots of shapes and sizes
- Don’t have a cellular structure – have a protein coat round some genetic material (either DNA or RNA)
- Examples: HIV, influenza virus, tobacco mosaic virus
What are pathogens?
Organisms that cause disease eg some fungi, proctotists, bacteria and viruses
