Adaptations Flashcards
(165 cards)
1
Q
what is an adaptation?
A
Genetically controlled.
Structural, behavioural or physiological.
It enhances the survival of an organism in particular environmental conditions.
2
Q
what are the two challenged to adaptation and survival?
A
Biotic: mates, competition, parasites.
Abiotic: water, oxygen, temperature, soil, gas, humidity.
3
Q
what is the tolerance range?
A
Every organism has tolerance to factors such as temperature, desiccation (drying out), oxygen concentration, light intensity and UV exposure.
Any factor that exceeds the limit of tolerance is a limiting factor.
The tolerance range defines the environment in which an organism can live.
4
Q
what is a limiting factor?
A
Any condition that approaches or exceeds the limits of tolerance
5
Q
what are properties of water?
A
Cohesive- stick together.
It is the predominant solvent.
Restricts temperature change and has a high heat of vaporisation (evaporation).
Solid water is less dense than liquid water.
6
Q
what is high heat of vaporisation? how does this help cool animals down?
A
High heat of vaporisation is an important factor in cooling animals with heat stress (kangaroos lick themselves).
Heat energy needed to evaporate the water is taken from warm blood close to the skin which cools the blood and thus the core.
7
Q
what are adaptations for survivng in a desert? how is water gained and lost?
A
Survival without drinking: eating things with water, concentrated urine, few sweat glands (structural), dry faeces (physiological).
Water gain: dew, burrowing to stop water loss, metabolic water.
Water loss: evaporation from skin, faeces, loss in exhaled air, urine, milk from mother.
8
Q
how does survival by dormancy work?
A
Some frogs make a moist burrow in sealed clay with mucus when water dries up.
They can be buried for 1-2 years.
9
Q
how does survival by moving around work?
A
move to where more resources are
10
Q
what is an example of surviving through offspring?
A
producing drought resistant eggs
11
Q
what is temperature related stress?
A
Animals in hot environments often experience stress due to body temperature, water and salt balance.
12
Q
how does hibernation help species in the cold? what is it triggered by?
A
Hibernation.
They reduce energy requirements and can be protected.
It is triggered by scarcity of food, lowing of temperature, endocrine responses to changes in the day light cycle.
Sudden or large environmental changes.
Temperature is reduced but always above freezing (no movement).
The temperature in the burrow is relatively constant.
13
Q
why can ice damage or kill? how is this solved?
A
Reactions essential to life occur in liquid water, they can not occur in ice.
When water freezes, it expands, frozen cells rupture.
Water with salt doesn’t freeze until about -18 degrees.
Some organisms make an anti-freeze with glycerol, amino acids, sugars or mixtures.
They are released into their body fluids.
14
Q
how do animals keep warm with adaptations?
A
Penguins huddle (behavioural). Insulation (fat/fur). Antifreeze chemicals. burrows. Metabolic heat.
15
Q
what adaptations do mammals in water have?
A
Oxygen storage in lungs and in body tissues- more red blood cells.
Insulating layer of fat or blubber.
Antifreeze proteins circulate in the blood.
16
Q
what are some adaptations in plants?
A
Maximise water uptake.
Minimise water loss: transpiration through the stomata must be limited (rolled leaf or hairy leaf)
Produce drought-resist seeds.
Silver or glossy leaves reflect more light and lower leaf temperature.
Small narrow or cylindrical leaves have more surface area so gather less heat in the sun and lose less water.
Thin parts of leaves lose more heat. Leaves that have more thin margins or edges get less hot and lose less water.
Leaves that hand vertical also obtain less sunlight directly and get less hot.
17
Q
what are some adaptations of leaves? (4)
A
Succulents such as prickly pares have no leaves. They can store lots of water in their thick bodies.
Trees with fine needles can prevent build up of snow on them.
Salt bushes excrete salt crystals onto their leaves which reflect light. They also have sunken stomata and are covered in hairs and have good leave orientation.
Rolled up leaves to prevent water loss.
18
Q
how do plants survive in the cold and ice?
A
When ice forms in living plant tissue, water leaves cells and adds to the ice.
The ice grows in the gaps between cells.
Though the ice punctures the the cell walls, the membranes are just pushed back and the cells stay intact.
The inside of the cell doesn’t freeze because of the concentration of ions in the cytosol lowers freezing temperature.
19
Q
what are problems with plants growing in water? what do they do to cope?
A
Problems- lack of oxygen and lack of light if submerged.
They may have air- filled spaces for buoyancy.
Stomata may be on the upper side of the leaf.
There may be a thin cuticle for diffusion of gases.
20
Q
what are adaptations plants use to move controlled by hormones and turgor pressure?
A
Tropisms- a plant growth in response to an environmental factor and has a direction (plants grow towards sun).
Nastic movement- movement of a plant in response to an environmental stimulus but not in the direction of that stimulus.
21
Q
where do mangroves live and what do they need to adapt to?
A
Grow in intertidal zone on shallow muddy shores.
They need to adapt to: changing salinity levels with the movement pf tides or from total rivers, lack of oxygen to their roots in waterlogged soil, boggy and unstable soil that makes anchorage hard, seed dispersal in an aquatic environment.
22
Q
how do mangroves get rid of salt?
A
Exclusion: actively pump salt out across the membranes of roots.
Excretion: from glands in leaves.
Accumulation.
23
Q
describe the specialised roots of mangroves.
A
Oxygen normally enters roots through lenticles which are rough spots consisting of loose, corky tissue through which gases can diffuse.
They have evolved aerial roots that all have lenticles (peg roots, pneumatophores and stilt roots).
Pneumatophores increase the surface area exposed to the air at low tide for maximum oxygen uptake
Aerial roots with cable roots that spread laterally to stabilise the plant in soft mud.
Cable roots have a mat of fine, hair-like roots that absorb nutrients and water.
24
Q
how do mangroves disperse their seeds?
A
Seeds of mangroves are buoyant.
Some mangroves are viviparous.
Viviparity means that the seed germinates and develops while still attached to the parent plant.
It falls into the water when it has a developing root system.
This enables it to anchor itself before washed into the waves.
25
what is classification?
Each organism can be names and placed into particular groups- taxonomy.
26
what are aspects of biological classification?
Diversity
Evolution
information
International sharing of information
27
what is biodiversity?
Variety of life forms, plants, animals, microorganisms and ecosystems they inhibit.
28
what does recording allow us to do?
Recording allows us to know of species existence, which species are most endangered, which need protection and which can be used safely for the benefit of people.
29
what is species diversity?
: variety of different kinds of organisms in a particular habitat or region.
30
what is genetic diversity?
variety of genes or different inherited characteristics.
31
what is ecosystem diversity?
variety of physical environments.
32
why is the binomial system used? what is it? what is it made up of?
Scientists need to refer to species the same way to understand and communicate.
Species are referred to by their scientific name.
It is a two part name- binomial.
Genus and then species (lower case).
33
what is a genus?
many species
34
what is species?
Differences in morphology (form/structure) are used to divide organisms into species.
Biological species are able to reproduce and have fertile offspring.
35
what is biological classification? (2)
Linnaean system is a hierarchy placing species into groups that are increasingly more inclusive.
At each level the difference becomes greater.
eg. kingdom, phylum etc.
36
what are subspecies?
slight variation in form across different locations.
37
what is a hybrid?
offspring of two interbreeding species, most are sterile.
38
what is phylogenetic classification?
Patterns of morphology or genetic characteristics can be represented in a branching phylogenetic tree.
Shows evolutionary relationship between organisms.
39
what are the five kingdoms? what is a newer idea?
```
Protista (unicellular eukaryotes)
Plantae
Animalia
Fungi
Monera (bacteria prokaryotes)
domains
```
40
what are the three domains?
Bacteria
Archaea
Eukarya
41
what are tools for classification?
Field guides
Data base
Reference collection
Dichotomous key- using recognisable features
42
how is genetic material being used to classify?
Increasingly genetic material is being used for identification.
Look for the presence of known markers.
Use hair follicles, tissue, blood, scats.
DNA bar coding.
DNA sequences can show variation over the geographical range of the species.
43
why should biodiversity be managed?
Aesthetic
Ecological value: plants produce and provide, animals pollinate and provide food, microorganisms decompose.
Practical value: food, medicine, industrial needs, breeding stocks, crop pollinators, diversity in genes, future resources, biomimicry.
44
why should habitats be conserved?
Save species from extinction.
| Inter-relationship of species.
45
what are strategies for managing the earth's biodiversity?
```
Conservation of species:
under threat of extinction.
Ecological importance.
Economic value.
Cultural of social importance (in situ- in natural habitat, ex situ- in captivity).
```
Establishing protected areas:
habitat loss.
National parks.
Prevention and control of invasive species:
pest organisms- foxes, rabbits, cane toads etc.
Biological control- use of natural predator, parasite or pathogen.
46
what are examples of technology that control pest species?
Infecting rabbits with a virus that includes a modified gene that stops conception in females.
Carp- a gene is switched off in females so that they only have male offspring.
47
how can pollution be managed?
```
Reduce industrial waste.
Reduce use of fossil fuels.
Energy efficient appliances.
Environmentally friendly products.
limit use of chemical fertilisers, herbicides and pesticides.
```
48
what is climate change caused by?
increase in CO2 levels
49
how does overexploitation occur?
```
Food
Construction
Industrial products
Fashion
Medicine
```
50
how can resources be used sustainably?
Resources are consumed no faster than they can be replaced naturally.
51
what is bioprospecting?
Search for new plant and animal substances for medicines or other uses.
anti-cancer properties
Fight-disease
Many medicines are found in the Amazon
52
how is an equilibrium maintained in the body?
by homeostasis
53
what is homeostasis? what environments does it involve? how is it maintained?
The maintenance of a relatively stable internal environment in the face of a changing external environment.
Involves internal and external environments.
Maintained by endocrine and NS.
54
how does communication in the body occur? what is the exocrine system?
Chemical and electrical in the nervous system.
Hormones and neurotransmitters.
Chemical messages in the endocrine system (inside). Travels in the circulatory system.
Exocrine system involves tears, saliva and sweat (outside).
55
what is the positive feedback system? what are examples? is it in homeostasis?
Not found in homeostasis.
Examples are ethylene and bananas ripening- makes others ripen.
Breastmilk production- baby suckles=milk production.
Same direction as stimulus.
56
what is negative feedback? what is It involved in?
Very important in homeostasis as it counteracts the initial stimulus.
If the body gets hot, the body tries to cool it down.
The response is in the opposite direction of the stimulus.
57
what are the 5 stages of the stimulus response model?
```
Stimulus
Receptors detect change
Control centre (often the brain)
Effector
Response
```
58
what is the NS composed of and what is it organised into?
```
The nervous system is composed of highly specialised cells called neurones which are organised into:
the CNS (brain and spinal cord).
The PNS (extending to the rest of the body).
```
59
what do sensory, motor and interneurons do?
Sensory neurones transmit messages form receptor organs to the CNS.
Motor neurones transmit impulses from the CNS to effector organs.
Interneurones (connector neurones) relay messages between neurones.
60
what is information flow in the neurone?
```
Sensory receptor
Sensory input
Integration
Motor output
Effector
```
61
what are aspects of a neurone?
Cell body- where the nucleus is located.
Dendrites- receive signals from adjacent neutrons and conduct them towards the cell body.
Axon- transmit signals away from the cell body.
Myelin sheath- helps increase the speed of the nerve impulse.
Synapse- gap between, chemical messages, Its travel here.
62
what part of the NS is the FF response? what are aspects of each branch and what does it do?
Part of the autonomic NS.
Prepares the body to stay and fight or flee from a threat.
The sympathetic NS world in a stressful situation to fight or flight.
The parasympathetic NS works to relax the body and maintain homeostasis.
63
what does the parasympathetic NS do?
```
Stimulates flow of saliva
Slows heart
Constricts bronchi
Stimulates peristalsis and secretion
Stimulates release of bile
Contracts bladder
```
64
what does the sympathetic NS do?
```
Dilates pupils
Inhibits flow of saliva
Accelerates heart
Dilates bronchi
Inhibits peristalsis and secretion
Conversion of glycogen into glucose
Secretion of adrenaline and noradrenaline
Inhibits bladder contraction
```
65
what is the spinal reflex?
A reflex is a rapid, automatic response to a stimulus.
Minimises damage
Unconscious
Controlled by the spinal cord
66
what is the reflex arc? what are components of it?
```
Nerve pathway for reflex action.
Only two neurones: sensory and motor.
Receptor
Sensory neurone (afferent)
Integration centre (CNS)
Motor neuron (efferent)
Effector
```
67
what is the patella reflex?
Monosynaptic (one synapse), just sensory and motor neurones.
Hit kneecap or patella.
68
what do receptors do and what are the different types? (5)
```
Detect changes in the external and internal environments.
Photoreceptors (light).
Mechanoreceptors (pressure).
Chemoreceptors (chemicals).
Pain.
Thermo receptors (heat).
```
69
how specific are the NS and HS?
highly specific; target cells- specific
70
how fast is the NS and HS?
extremely rapid; slower
71
how long is the duration of the NS and HS?
short; long lasting
72
which system requires more energy?
the NS because of the brain.
73
what forms do the messages travel in the NS and HS?
electrical (axon) and chemical (synapse); chemical
74
what does the endocrine system control?
The endocrine system controls levels of glucose in the blood, hydration levels, heat productivity, sexual maturity, sperm and egg production and growth of cells and tissues.
75
what are the two ways that hormones target cells?
internally- across a membrane
| Externally- receptor on a cell
76
what are the two main types of hormones?
fatty acids: steroids, oestrogen, testosterone, lipids (can pass through).
Amino acids: adrenaline, GSH (cannot pass through).
77
what is a hormone? where is it released?
A chemical that acts as a message in the body.
| Released from the endocrine gland into the blood affecting the function of specific cells.
78
how do hormones produce a response in cells? where may target cells be located?
specific receptors can respond to the hormone.
The binding hormones produce a response by the target cell.
They exert effects directly (pass through membrane) or indirectly (interact with receptors on surface).
Target cells may be anywhere in the body.
79
why are hormonal messages slower?
they rely on diffusion
80
what are the three types of hormones?
```
Peptide and protein hormones: water-soluble, cannot pass through, stimulate receptors on surface.
Amino acid derived hormones: water-soluble, cannot pass through, bind with specific receptors on cells.
Steroid hormones (synthesised from cholesterol): small and lipid soluble, can pass through and then bind with receptors.
```
81
what secrete hormones and what is the endocrine gland?
Specialised cells can secrete hormones.
| Clusters of these cells can also form endocrine glands which secrete hormones.
82
where is the pituitary gland located? what does it do and what structure does it work with?
Gland at base of brain under hypothalamus.
Hypothalamus receives information.
Pituitary gland uses this info to cause changes by secreting hormones.
83
what does the hypothalamus control?
Hypothalamus (info collecting centre) controls the release of hormones from the pituitary gland.
84
what is the pituitary gland involved in?
Rhythmic patterns.
Detects and responds to light.
Produces melatonin.
Biological clock- jet lag.
85
what is a set point and what in an example?
There are homeostatic set points eg. The body should be 35.6-37.8 degrees.
86
why must the body cool down if it gets too hot? or too cold?
If the body gets too hot, it must cool down because enzymes that catalyse reactions fall apart of denature.
If it gets too clod, the body must warm up because the molecules slow down and chemical reactions do not occur as well.
87
what are ectotherms? how do they function and how do they lose and gain heat?
```
cold blooded.
Unable to heat internally.
Lose heat to their environment.
Use less energy- cant afford to use it.
Function slowly.
Require heat source from outside:
bask in the sun
Environment dictates body temperature.
```
88
what are endotherms? what are some examples? what insulating features do they have? how do they compare to their environment? how constant is their temperature?
```
Birds and mammals.
Relatively constant body temperatures.
Hotter than environment.
Internal metabolic heat- physiological.
Insulating features:
Fur
Feathers
Fat layers
```
89
what are the four ways that a body loses heat?
evaporation: loss of heat by evaporation of water.
Radiation: emission of electromagnetic radiation.
conduction: direct transfer by contact.
convection: moving air removes radiated heat.
90
how so organisms reduce heat loss? (5)
Vasoconstriction
Seek shelter
Piloerection (goose bumps)- insulates when hairs stand up, better with furry animals.
more clothes- trap air which insulates.
curl up- decrease SA:V to reduce amount exposed.
91
how do organisms produce heat? (3)
shivering: uses energy and heat is produced from cellular respiration.
Brown fat: burns up food to create heat- babies and young boys have this, true over glucose quickly, skinny however much you feed them.
Metabolism (C.R.): controlled by hormones and determines the rate of cellular respiration which produces heat.
92
how do organisms respond to the heat? (7)
Sweating- evaporative cooling. Energy is needed for liquid to gas and this is heat energy from skin- removes energy.
Vasodilation
Slowing metabolism (C.R.)
Move to shade, remove clothes, spread body out.
Covering body with H2O- evaporation.
Swimming: loss of head through conduction.
Decreasing activity.
93
what are circulatory changes that regulate BT? and what are two examples of this?
smooth muscular responses controlled by the nervous system: selective constriction or dilation of blood vessels in the skin.
Vasoconstriction- blood vessels have thicker walls and less blood passes through. This means less blood travels under and as close to the skin so less heat is lost.
Vasodilation- blood vessels get thinner walls and more blood passes through. This means more blood travels under and close to the skin so more heat is given off.
94
what is the thermoregulatory centre? where are thermoreceptors located? what structure carries out the responses?
The hypothalamus is the Thermoregulatory Centre.
Thermoreceptors in the hypothalamus detect blood temperature.
Thermoreceptors in the skin detect external temperatures.
hypothalamus
95
how does countercurrent work? what animals use this?
This keeps the feet of penguins and tongues of whales from loosing too much heat.
The artery goes down the foot and right next to it is a vein.
The blood in the artery is hot and the blood in the vein is cold from being near the surface.
To reduce heat loss, the artery cools down a bit by being next to the cold vein.
To make sure cold blood does not go into the body too far, the vein is warmed up by the artery.
96
what is blood glucose level? what causes changes in it? how is it managed?
concentration of glucose in blood.
eating and exercising change levels.
Managed by homeostatic mechanisms.
97
when is insulin produced?
when carbohydrates are eaten.
98
what is glucose stored as and how is this used?
Glucose is stored as polymer, glycogen.
| Glycogen is broken into glucose when glucose is needed.
99
what is hypoglycaemia? hyperglycaemia?
Hyperglycaemia (BGL too high).
| Hypoglycaemia (BGL too low).
100
how are BGL detected?
Cells in pancreas detect changes.
Cells in pancreas release insulin and glucagon to maintain levels.
Glucose-sensing neurones in hypothalamus also detect change.
101
how is high BGL responded too?
Islets of Langerhans (clusters of specialised cells in pancreas) release insulin.
Insulin converts glucose to glycogen, fats or fatty acids for storage in liver and skeletal muscles.
Lowers BGL.
102
how is low BGL responded to?
Islets of Langerhans release glucagon.
| This hormone stimulates the conversion of glycogen to glucose which raises BGL.
103
about how much of our bodies are water?
65%
104
what is water regulation important?
An important competent of cells.
Most metabolic reactions take place in water.
Water is responsive for carrying nutrients eg. Blood.
Gas exchange surfaces have to be moist.
105
what is osmoregulation? what is it controled by? what excess materials are removed in urine?
The process of regulating the concentration of water and mineral salts in an organism in order to prevent fluids from becoming too concentrated or too dilute.
Controlled by osmosis: water intake and loss: passive diffusion of water across a semi-permeable membrane from dilute to concentrated.
Urea and excess salts are removed in urine.
106
what is water lost in?
```
Urine
Faeces
Sweat
Tears
Breath
```
107
what is water gained in?
Drinking
Eating
Metabolic reaction such as cellular respiration.
108
how does the kangaroo rat regulate water and save water?
Remains in cool burrow during the day.
Respiratory moisture condensed in nasal passages.
Metabolic water derived from dry seeds.
Urine concentrated by long loop of Henle.
Free water in seeds.
109
how do mammals maintain a water balance? what determines how much water is reabsorbed?
Maintain water balance through kidney.
Actively pump salts into medulla.
Countercurrent arrangement in the kidney.
The length of the loop of Henle determines how much water is absorbed.
110
how is salt gained and lost? what filters slat from the blood? where are most salts reabsorbed?
Salt is gained in food.
Salt is lost in urine, sweat and faeces.
Kidney filters excess salts from blood and excretes them into urinary system.
Most salts are reabsorbed in the blood plasma.
111
what monitors water and solute concentration? what happens when extracellular fluids change?
Water and solutes concentration monitored by osmoreceptors in hypothalamus (sensitive to blood solute concentrations) and baroreceptors in atria of heart (detect changes in blood pressure).
Changes in concentrations of extracellular fluids affects concentrations in cytosol (osmosis)- bad.
112
what hormone regulate water reabsorption? where is it made and where ia it stored?
Antidiuretic hormone (ADH)
Made in hypothalamus.
Stored in pituitary gland.
113
how is ADH released and how does it work? what happens if there is too much eater and what can interrupt ADH production?
Osmoreceptors in hypothalamus detect an increase in osmolality of the blood (blood solute concentrations) and ADH is released from pituitary gland.
It works in kidneys where is increases permeability to water of tubules and collecting ducts.
The kidney has high salt concentrations so water is drawn out and reabsorbed.
Urine becomes more concentrated.
If there is too much water secretion of ADH is stopped.
nicotine, caffeine and alcohol can interrupt the ADH production- pee more.
114
what are malfunctions in homeostasis?
Genetic disorders.
Ageing
Poor nutrition, lack of exercise
115
what are hyper secretion and hypo secretion?
hyper secretion- oversupply
| Hypo secretion- undersupply.
116
what is type 1 diabetes a malfunction of? what does it cause? when does it occur? what do people have to do to manage it?
```
Malfunction of pancreas.
Autoimmune- destroys own insulin producing cells, therefore can’t produce enough insulin to convert glucose to glycogen, BGL increase to dangerous high.
Often occurs in childhood.
Monitor BGL daily.
Inject or pump insulin.
Transplant pancreas.
Gene therapy- experimental.
```
117
where are thyroid hormones secreted from? what is the thyroid gland involved in? what is it regulated by?
Secreted by thyroid gland (neck)
Thyroid gland- growth, development, metabolic rate, cardiovascular, reproduction and CNS.
Must be tightly regulated by negative feedback.
118
what is hyperthyroidism? what does it cause?
```
Excessive hormone production effects 6-7% pop.
Autoimmune disease- Graves Disease
increased basal metabolic rate
Hot, weight loss, heart rate
Restlessness, trouble sleeping
Goitre
Bulging eyes
Treated by drugs: beta blockers or surgery (remove goitre).
```
119
what are biotic factors? abiotic factors?
Biotic (living):
biological part of environment.
animals, plants, microorganisms…
Abiotic (non-living):
physical part of the environment.
Soil, rocks, air…
120
how do humans impact the environment?
```
Introduce pests.
Have roads and run over animals.
Acid rain.
Climate change.
Deforestation.
Pollution.
```
121
what is an individual or organism?
single organism
122
what is a population?
A group of organisms of the same species.
123
what is a community?
An ecological grouping of different kinds of organisms that live together in a particular place at a particular time and interact with each other.
124
what is an ecosystem?
A system formed by formed by organisms interacting with one another and their physical environment.
Self-sustaining and does not need inputs from an outside system.
125
what is a biome?
A group of communities that have similar structures and habitats extending over a large area eg. Rainforest or tundra.
126
what is a biosphere? what is it made up of?
```
All ecosystems on earth.
The atmosphere as well.
Largest and most complex ecosystem.
Lithosphere (soil and rocks).
Hydrosphere (oceans, rivers, lakes).
```
127
what is a habitat? what is it made up of? how many habitats do organisms have?
A type of place where an organism lives.
Some only have one type of habitat (low tolerance).
Some in many habitats.
Has abiotic factors.
Biotic factors: food and predators.
128
what is a microhabitat? what could it be?
Small areas in a habitat.
Could be a burrow or tree canopy of inside another organism.
Slightly different environment to overall habitat.
Variations in the microhabitat can be essential for survival.
129
what is an ecological niche?
Its role in the environment.
How it uses resources and interacts with others. A particular environment where a species is likely to persist indefinitely- where they can survive and reproduce.
130
what is the competitive exclusion principle?
two species cannot have the same niche in an ecosystem.
| Animals can use different parts of the same resource. q
131
what are interactions within and without species and which is more intense? what other interactions are there?
```
Intra-specific: within a species.
Inter-specific: between different species.
Beneficial interactions
- mutualism
Benign interactions
- commensalism
Harmful interactions
parasitism
Amensalism
predation
```
Infraspecific is more intense as members of the same species will compete more intently as their requirements are the same.
Feeding and non-feeding interactions.
132
what is symbiosis?
Different species living together in close partnership.
133
what is mutualism?
An interaction where both organisms benefit in some way.
| There may be adaptations that help the relationship eg. Most flowering plants attract animals in some way.
134
what is commensalism?
One member of the interaction benefits whilst the other is neither harmed nor benefited.
135
what is parasitism? what does a parasite do to its host?
One organism (parasite) lives in or on another (host).
Parasites are benefited whilst the host is harmed. The parasite does not mean to kill the organism but it may shorten its lifespan, impair functions, make it less able to withstand stressors or have greater vulnerability to predators.
A parasite may have more than one host in a life time.
A host that transfers a parasite to another host is a vector.
All organisms have parasites.
136
what is amensalism?
One species is inhibited or killed whilst the other is unaffected.
An example is goats destroying vegetation but not being affected.
137
what is predation? what are characteristics of predators and prey?
When one species (predator) kills and feeds off another (prey).
Predators are carnivores.
The predator may have claws, sharp teeth, speed, webs, poison, enhanced sense organs, lures or hunting strategies.
Prey may have camouflage, speed, poison/repellant glands, hiding strategies, safety in numbers, spikes/hard shell, mimicry, play dead or keeping lookout.
138
what are food chains? what are two main groups? how is energy moved?
Links all organisms according to their feeding relationships.
Two main groups are producers and consumers.
Energy is captured by producers and then injected by consumers and another consumer ect.
Energy is transferred.
Arrows show the flow of energy.
139
what are producers? what is another name? where are they in a food chain? what are two types of autotrophs?
Plants produce their own food, they are autotrophs.
Autotrophs are called producers.
First link in the chain.
Produce organic compounds from inorganic compounds.
Photosynthetic autotrophs: make food using energy from sun.
Chemosynthetic autotrophs: obtain energy from producing organic compounds from inorganic molecules directly.
140
what are consumers? what are the different types? what are the classified as? what is a top carnivore?
All organisms that are not producers.
They are heterotrophs.
herbivores, carnivores, omnivores, parasites, scavengers (consume dead animals) , detritivores (feed on dead plants and animals), decomposers (break down and consume non-living organic material).
Classified as primary, secondary, tertiary etc depending on their position.
If there is no-one to eat an organism, it is the top carnivore.
141
what are predator-prey food chains?
Predators usually eat organisms smaller than them.
| Many food chains are this.
142
what are parasite-host food chains?
Parasite-host food chains have a large organism (the host) as a source of food for smaller organisms (parasites).
143
what are detritivores and decomposers?
detritivores: snails, worms, termites, millipedes and mites.
Decomposers: fungi and bacteria.
144
where are decomposers in a food chain? what do they eat? how do they break down food?
Final link in the chain.
Use materials left by all other organisms.
Deal with carcasses and wastes.
Make these things into simple inorganic compounds.
These compounds are used by autotrophs. Decomposers secrete enzymes to break down food.
145
what are food webs?
A more complex food chain that shows the different things (not just one) that species eat or are eaten by.
146
what are trophic levels? what organisms are on the levels?
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A feeding level.
Producers make up the first level.
Herbivores the second.
Secondary consumers are in the third.
Each level feeds on the on below.
An organism may be in more than one level.
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147
what happens if a food web changes?
Because of interconnectedness, often the whole web is affected.
The more complex the web, the less disastrous as there are other food options
148
what is a keystone species? what happens if it one is removed?
A keystone species is one that plays a critical role in maintaining the structure of their ecosystem.
When one is removed, the web becomes unstable.
Usually the top if the food chain.
Control the number of other species.
149
what are population dynamics?
Involve the studying of how a population changes over time.
150
what is geographic distribution? how might it change?
All the places where a specific species can be found.
| This changes as habitats and climates change.
151
what is abundance or density? what happens if the whole thing cannot be sample? how can it be represented?
Number of individuals per unit area (or volume).
Sometimes the whole area cannot be sampled- parts are sampled and then the total extrapolated.
Can be represented quantitively- rare, frequent, abundant.
152
why should we measure abundance?
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Changes over time.
Elimination of pest species.
Measuring biodiversity and health.
Endangered species.
Finding out why some populations increase and others do not.
Varies depending on the resources.
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153
what is distribution and how can it occur?
spread of members of a population over space.
Uniform distribution.
Random distribution.
Clumped distribution.
154
how do populations grow and fall?
Growth is a result of birth and death and migration and emigration rates.
Birth and migration- bigger
Death and emigration- smaller
Change in pop size= (B+I) - (D+E)
155
describe exponential growth? what species are usually involved?
J shaped curve.
Cannot continue forever
Growth continues until there is environmental resistance eg. Not enough space.
Species that have short generation time and large no. of offspring.
156
what are density-independent factors and what factors can influence the tolerance range?
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Density-independent factors- regardless of pop. Size
Tolerance range- abiotic factors
Temp
Sunlight
Salinity
Humidity
Wind strength
Water availability
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157
what change the environment in a major way?
Natural disasters.
| Human-made changes.
158
what are density dependent factors? how do they increase and what are some?
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Factors that influence rate of births and deaths.
Increase as populations increase.
Predation
Crowding
Parasitism
Infectious disease
Competition
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159
what is competition? what are two types of competition? what happens to the loser?
The struggle between organisms for an environment resource that is limited.
Intraspecies and interspecies competition- there is a winner and a loser.
The loser must die, leave or change the way it uses resources (niche separation).
160
what is predation?
Size of one pop is affected by the size of the other.
| Lots of predators, few prey etc.
161
how can crowding influence a population?
Crowding can affect the population in different ways.
| Under stress- fewer offspring.
162
how does parasitism increase?
Increased density allows them to invade and spread.
163
how do infectious diseases spread? how is rate affected?
Spread faster in denser populations
| Rate of spread is dependent on wind, water, temp, genetic diversity
164
what is carrying capacity?
The maximum number of organisms that the environment can sustain indefinitely without environmental degradation.
Balance in birth and death.
165
what are factors that affect carrying capacity?
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Weather and climate change
Major changes in an environment
Fluctuation in populations of food species or consumers
Abiotic: soil, water, space, shelter
Biotic: fluctuations in species
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