Variety of organisms - Unit 1 Flashcards
(36 cards)
there are 8 characteristics of a living organism. What are they?
the 8 characteristics are..
- move
- respire
- sensitivity
- control internal conditions
- grow
- reproduce
- excrete
- need nutrition
characteristic 1: Move
- animals move from place to place
- organisms can move towards food/ water
- organisms can move away from predators
- plants can move slightly but not from the spot
characteristic 2: Respire
- respiration is the release of energy from food (glucose)
- Aerobic respiration: Glucose + oxygen -> carbon dioxide + water
- Anaerobic respiration in animals: glucose -> lactic acid
- Anaerobic respiration in plants and yeast: glucose -> ethanol + carbon dioxide
characteristic 3: Sensitivity
They can respond to changes in their movement (a stimulus)
Examples include reflex actions such as moving your hand away from a hot objet (reflex arc).
And the iris reflex (dilating in dim light, constructing in bright light).
characteristic 4: Control inter conditions
Homeostasis - maintenance of a constant internal environment.
Thermoregulation - maintenance of constant internal temperature.
Osmoregulation - maintenance of water levels.
characteristic 5: Grow
Increase in size/ mass of an organism, increase in number of cells.
characteristic 6: Reproduce
Produce offspring
sexual reproduction: involves fertilisation of gametes (sex cells), offspring are genetically different, results in variation within species.
Asexual reproduction: 1 parent, involves cell division by mitosis, genetically identical offspring.
characteristic 7: Excrete
Removal of waste metabolic products
- carbon dioxide from respiration (removed by lungs in animals, stomata in plants)
- urea from excess amino acids (removed by the kidneys, in urine)
characteristic 8: Need nutrition
Requiring such as…
glucose to provide them with energy (through respiration).
Proteins for amino acids.
Vitamins and minerals.
(specifically mineral ions in plants - very important)
Why are viruses not considered living organisms?
Because they do not…
- respire
- move
- excrete waste products
- require nutrition
- grow and develop
- control internal conditions
- respond to their surroundings
- reproduce without a host
what are eukaryotic cells
Complex cells
Includes all animal and plant cells
Plants, animals, fungi and protoctists are all eukaryotic organisms -> they have a nucleus and a membrane bound organelles.
what are prokaryotic cells
Smaller and simpler
e.g -> bacteria
Bacteria are prokaryotes -> no nucleus - just circular chromosome (nucleoid) and plasmids.
What are the 5 kingdoms?
- plants
- fungi
- animals
- protoctists
- bacteria
about plants…
Multicellular (made of many cells)
have chloroplast which contains chlorophyll
photosynthesis to produce glucose
cell walls made from cellulose
store carbohydrates as starch (& sucrose)
about animals…
multicellular (made of many cells) no chloroplast - do not photosynthesise no cell wall have nervous coordinations move from place to place store carbohydrates as glycogen
about fungi…
some are multicellular (body called a mycelium)
some are unicellular
cannot photosynthesis
cell wall made from chitin
store carbohydrates as glycogen
feed by saprotrophic nutritions (food digested outside body and nutrients absorbed)
about protoctista…
unicellular (single celled)
some have chloroplast (like plant cells)
others more like animal cells (no chloroplast)
name 2 examples of protoctists
chlorella -> plant like
amoeba -> animal like
about bacteria…
Single celled No nucleus (prokaryotes) Circular chromosome of DNA Some can photosynthesise Usually feed off other organisms e.g of bacteria -> lactobacillus (used in yoghurt production) and pneumococcus (causes pneumonia)
about viruses…
NOT A KINGDOM, NOT LIVING
Particles much smaller than bacteria
Reproduce inside living cells (parasites)
Protein coat surrounding genetic material
e.g of viruses -> influenza virus, tobacco mosaic virus, HIV
What are pathogens?
A pathogen is an organ which can cause disease.
It may include fungi, bacteria, protoctists, or viruses.
Some bacteria - eg Pneumococcus (causes pneumonia).
Some protoctists - eg Plasmodium (causes malaria). Mosquitos are a vector (transmitters) for malaria, but they do not cause it.
Viruses eg - Influenza virus (causes flu), HIV (causes aids), and TMV (a virus which affects plants)
Some fungi are also pathogenic
what are cells?
A cell is the basic structural and functional unit of life.
what is a tissue?
A tissue is a group of similar cells that work together to carry out a particular function.
what is an organ?
it is a group of tissues that work together to perform a function.
