Variety of organisms - Unit 1 Flashcards
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.
what is an organ system?
it is organs that work together to do a job
animal cell structure
REMEMBER TO LOOK AT A DIAGRAM OF THE CELL
nucleus - contains genetic material that controls cells activities.
cell membrane - controls what enters and leaves the cell
cytoplasm - where aerobic respiration takes place
Mitochondria - where aerobic respiration takes place
Ribosomes - where proteins are synthesised
(these organelles are found in BOTH plant and animal cell)
plant cell structure
REMEMBER TO LOOK AT A DIAGRAM OF THE CELL
additional organelles:
chloroplast - contain chlorophyll which trap light energy, where photosynthesis occurs
cell wall - made of cellulose - provides structure for the cell
vacuole - contains cell sap, to support the cell by keeping it turgid.
(same as animal cell):
nucleus - contains genetic material that controls cells activities.
cell membrane - controls what enters and leaves the cell
cytoplasm - where aerobic respiration takes place
Mitochondria - where aerobic respiration takes place
Ribosomes - where proteins are synthesised
(these organelles are found in BOTH plant and animal cell)
what are the 3 substances that move in/ out of cells and how does it occur?
- diffusion
- osmosis
- active transport
- it occurs across cell membranes, which are selective - only small molecules can pass through.
about diffusion…
It is the movement of particles from an area of higher concentration to an area of lower concentration.
it is passive and it does not require energy.
Examples of diffusion include oxygen diffusing, through alveoli in lungs, and carbon dioxide through stomata in plants.
LOOK AT DIAGRAM ON THE GOOGLE DOCS
about osmosis…
It is the movement of water from an area of high concentration to an area of low concentration across a partially permeable membrane.
Osmosis is passive.
E.g of osmosis: absorption of water from soil by root hair cells.
LOOK AT DIAGRAM ON THE GOOGLE DOCS
about active transport…
It is the movement of particles against a concentration gradient (from low to high concentration) requiring energy.
E.g of active transport: absorption of mineral ions from the soil by root hair cells.
LOOK AT DIAGRAM ON THE GOOGLE DOCS
What are the 4 factors that affect the rate of diffusion, osmosis, and active transport?
- temperature
- distance
- concentration
- surface area of volume ration
what does temperature (increasing temperature) do to affect the rate of rate of diffusion, osmosis, and active transport?
- increases rate of diffusion
- particles gain energy
- move faster
how does the effect of distance (decreasing distance) affect the rate of rate of diffusion, osmosis, and active transport?
- increases rate of diffusion
- shorter distance for molecules to move over
(this is why most large organisms need transport systems, because diffusion would occur too slowly as substances have such a larger distance to travel over).
how does concentration (increasing concentration) affect the rate of rate of diffusion, osmosis, and active transport?
- increases the rate
- most particles available to move across cell membrane
- Steeper concentration gradient
how does surface area to volume ratio affect the rate of diffusion, osmosis, and active transport?
- smaller objects have a larger surface area to volume ratio
- increasing surface area to volume ratio increases the rate of diffusion. Substances can reach the centre of these objects faster.
