Zusammenfassung der Ressource
B3.3
- Interspecific Relationships
- Mutualism
- Definition: occurs
when both species
benefit from the
realtionship
- Examples: Small sea fish set up cleaning
stations , the larger fish then come to these
areas and will have their bodies cleaned of
parasites. The small fish benefit as they eat
the parasites and the big fish have their
parasites removed.
- Interspecific Competition
- Definition: non-cooperative relationship
between two organisms of
different species which results
in both being being negatively
effected at some point.
- Example: in animals competition
for; food, water, territories,
nesting sites. Always results in a
decrease in the reproductive rate
of the populaiton.
- Example: in plants competition for ;
water, sunlight, space, minerals,
pollinators. Influences plant growth rate
per plant and results ion variation in
growth of individual plants.
- Exploitation: an "aggressive" type
of behaviour that is beneficial to
one and harmful to the other
- Herbivory
- Definition: is the process
where by an animal eats
a plant or a plant-like
organism, like seaweed
- Predation
- Definition: a predator is an
organism that catches and
kills its prey for food
- Predator strategies include:
belonging to a group, using
snares, rapid speed, using poison
to stun or kill, camouflage and
lying waiting, using tools, using
mimicry
- Prey defences include:
living in groups for
protection, disruptive
colouration to disguise
outline of body, cryptic
colouration, retreating
into shell, startling
predator, chemical
defence, curling up,
confusion in large
numbers, pretending to
be inedible
- Parasitism
- Definition: parasites exist at the
expense of the host. They feed off
the host without killing it. The
population of parasites is density
dependent as they thrive in
crowded conditions.
- Ectoparasites: lives outside the body.
- Endoparasites: live inside the body
- Social Parasites: exploits hosts in other ways eg. cuckoos lay their eggs in others nests.
- Plant Parasites: compared to animals a much smaller proportions of plants are parasites,
eg. mistletoe grows on other trees by connecting to the vascular tissue of the host.
- Cooperative Intraspecific Relationships
- Group Formation
- Advantages: easier to find a
mate, easier to avoid
predation because; more eyes
to spot danger, defensive
circles, less chance of being
taken, confuse predator,
protection from abiotic
factors, greater learning from
each other, division of labour,
safer migrating as less likely to
get lost and more hydro and
aerodynam.ic
- Disadvantages: increased
intraspecific competition,
diseases and parasites are
transferred easily due to
close proximity, possible
infanticide due to
overthrowing male.
- How groups stay together
- Use signals such as odour, sound, visual and touch
- Suppressed aggression to allow mating
to occur, to protect young, to reduce
conflict between siblings, to maintain
heirarchy
- Mating Systems
- Monogamy: having only one mating partner
- Pair Bond
- Definition: a longer-lasting
relationship between a particular
male and female. Forms as a result
of courtship =, ensures co-operative
behaviour in mating and care of
young, which enhances their survival
chances.
- Advantages of monogamy:
use less energy searching
for a mate become
experienced parents
- Polygamy: having multiple mating partners
- Advantages of polygamy:
increases genetic
diversity, death of a mate
is not a lasting problem
- Polyandry: a female
having more than one
mating partner in a
season
- Courtship Behaviours Include:
- Smell eg. pheramones
- Visual eg. dances,
coloures markings,
firefly flashes
- Touch eg. male
spider vibrates the
web to stop female
spider from eating
him
- Vocal eg.
birdsong, crickets
stridulating, frogs
croaking
- Parental care strategies
- K-strategists qualities: stable
environment, large body size,
long-life expectancy, high
parental car, fewer offspring
- Advantages:
usually results
in successful
offspring
- Disadvantages: uses a lot of
energy to raise offspring,
parental care. Cecreases
liklihood of survival for
parents
- r-strategists qualities:
unstable environment, high
fecundity, small body size,
early maturity, short
generation time, dispersed
offspring
- Advantages: may exploit
favourable environments quickly
which allows them to outcompete
the other species. Don't use
energy over a long period of time
caring for offspring
- Disadvantages: must use a lot
of energy producing large
amounts of gametes/offspring
- Aggressive Intraspecific Relationships
- Fighting
- Occurs due to: intraspecific competition for
food, territory, mates, natural selection. young
animals play fight to learn skills and slot into
hierarchy. Agnostic behaviour in social animals
work to avoid most fights in those close in
hierarchy may fight for social position.
- Agnostic Behaviour
- Definition: aggressive and
submissive behaviours
involved in avoiding fighting
in social animals
- Territory
- Definition: the area an animal will defend
- Advantages of maintaining a
territory: only the "fittest"
animals can hold a territory so
only the best genes get passed
onto the offspring. Ensures
enough food and water for the
animals that hold the territory.
Reduces aggression. Ensures
safe, protected nest/home for
young. Reduces spread of
disease and parasites. it ensures
enough space for each animal,
which is needed for breeding.
- Bounrires of territory
marked by: vocalisations eg.
bird song, scent markings
eg. urine in dogs, visual
signals eg. crabs wave claws
- Home range: the
area an animal will
search for food and
nest sites.
- Hierarchies
- Linear hierarchies definition: a
form of animal social structure
in which a linear or nearly
linear ranking exists, with each
animal dominant over those
below it and submissive to
those above it.
- Advantages to living in hierarchy: once hierarchy
is established, there is decrease in aggressive
interactions in the group. The most dominant
animals, which have the 'best' genes will have
the most mates. This ensures that the 'best'
genes are passed onto the offspring. The most
dominant animals get the best and the most
food in some species the subordinate animals
may get more food than if they were living
indepently, as they could not bring down the kill.
The subordinate animals gain protection from
the dominant animals against external threats.
The subordinate is mire likely to find a mate than
if on it's own.
- Orientation in Space
- Tropism
- Definition: Growth
response of a plant
towards or away
from stimulus
coming from one
direction
- Auxin: are plant
hormones which play a
role in the observed
growth movements in
plants called tropisms
- The effect of auxin on the
shoots and roots depends
on the concentration of
auxins.
- low concentrations of auxin promote
root growth and high concentration
inhibit shoot growth and vice versa
- Phototropisms: is controlled by the hormone
auxin which is produced in the tip of the
shoot. It moves down the stem to the zone of
elongation. It promotes elongation of cells in
the shoot(upward growth). If light is shone on
one side of the seedling it will migrate to the
'dark side'. This results in the cells on the dark
side to have a greater concentration of auxin,
therefor they have more elongated cells
causing the shoot bend towards the source of
light= positive phototropism by the shoot
- Geotropism: is controlled by
auxin, and is the primary
regulator of the of the geotropic
response in plants. Geotropism
is due to the different growth
rates of upper and lower sides of
the stem root.Therefor the auxin
accumulates on the lower side of
the stem or root due to gravity.
High auxin in stems= cell
elongation. High auxin in roots=
no cell elongation.
- Nastic Movement
- Definition: The movement
of a plant in response to a
non-directional stimulus.
- Example: Mimosa leaflet
fold together and drop
down hen touched=
thigmonasty. This is a
defence mechanism
from animal herbivores
and conserves water
during windy conditions.
- Taxis
- Definition: The movement of the whole
organisms towards or away from a
stimulus coming from one direction.
- Klino-taxis:
moving
directly
towards or
away from
a stimulus
by moving
it's body
side to side
- Tropo-taxis:
moving
directly toward
or away from a
stimulus
without
moving the
body side to
side. The
stimulus is
detected
simultaneously
by receptors
on either side
- Telo-taxis:
orientation
towards a
stimulus
which occurs
whether or
not
symmetrical
organs are
functional.
There is no
need for
balanced
messages to
be recieved.
- Kinesis
- Definition: The change in the rate of
movement of the whole organism in
response to a change in the
intensity of a non-directional
stimulus
- Orthokinesis: the
speed of the
movement is
related to the
intensity of the
stimulation eg.
slaters move
faster under
bright light to
reduce the risk of
dessacation
- Klinokinesis: the
amount of
random turning is
related to the
intensity of the
stimulation eg.
flatworms turn
more under
intense light so
spend more time
in darkness
- Homing and migration
- Migration definition:
the annual mass
movement of
organisms from an
area where they
breed to an area
where they do not.
- Advantages: remain favourable
temp., constant food supply, better
breeding conditions, offspring
survival improved, can reduce
parasitism/spread of disease,
genetic mixing.
- Homing definition:
the ability of an
organism to find its
way home over
unfamiliar territory.
- Navigation Mechanisms
- chemical/oflaction:
involves taste or smell
eg. salmon return to the
stream they hatched to
breed years later
- Visual cues: using land marks like
the shape of coastlines, forests,
hills eg. birds
- Sound: bats,
dolphins, an
whales use sonar
to navigate.
- Sun compass: animal maintains a temporary fixed angle to
direction of the sun to calculate direction of travel, must be able to
compensate for the apparent movement of the sun so involves
knowing the time of day, using an endogenous clock eg.
insects,birds, fish. IF the internal biological clock is altered the
normal migratory direction is altered. A disadvantage is that the
sun is not always visible
- Star compass: used at night by nocturnal migrating birds, they
recognise star patterns
- Moon compass: sand hoppers move towards the sea at night time
using the position and use their internal clock to track this as the moon
has constant movement.
- Earth's magnetic field compass: bees, mice and pigeons can
detect the earth's magnetic field.
- Orientation in Time-Rhythms
- Biological Rhythms
- Circadian Rhythm: daily rhythmic
activity with a period of about 24
hours(1 day),Zeitgebers are light,
temperature, humidity changes
- Diurnal:
day
active eg.
dogs,
sparrows
- Nocturnal:
night
active eg.
bats
possums
- Crepuscular:
active at dusk
and dawn eg.
crickets, fruit
flies, rabbits
- Arhythmic:
no regular
pattern eg.
animals that
live in caves
- Circalunar Rhythm:
rhythmic activity with a
period of about 29 days,
zeitgeber is the light of a full
moon. eg. many marine
species liberate gametes at
certain times in the lunar
cycle.
- Circatidal Rhythm: rhythmic activity
period of about 12.4 hours(high tide to
high ides) eg. fiddler crabs emerge from
their burrows and feed at low tide.
- Circasemilunar Rhythm: rhythmic activity
activity period of about 14.7 days, zeitgeber
is related to spring(extra high) and
neap(extra low) tides, alternating every 2
weeks. eg. whitebait spawn during spring
tides in March and April
- Circannual Rhythm: rhythmic activity
with a period of about 365 days,
zeitgeber is usually photoperiodism(day
length). Involves seasonal behaviour.
- Hibernation: winter dormancy in
animals, metabolic processes slow,
body temperature drops, heartrate
and breathing drops, allows them to
survive very cold temperatures. eg.
squirrel, bear.
- Aestivation:
dormancy in hot
temperatures,
common in
desserts. eg.
garden snail,
earthworm
- Vernaliation: induction of
flowering by a period of
chilling(winter)
- Dormancy: seeds or
underground stems reduce
their metabolic rate to a
minimum level during
unfavourable conditions(low
temp, drought). Allows survival
until conditons improves
- Abscission: breaking off of leaves, fruits
and flowers as a result of the formation of
a layer of weakness at the base. Prevents
water loss in winter and the plant stores
proteins and minerals in the permanent
tissue of the tree.
- Perennial: plant that
flowers, seeds, flowers...
year after year
- Biannual: plant grows in
the first year, flowers and
seeds in the second then
dies
- Annual: a plant that grows,
flowers, seeds in 1 year then
dies
- Biological Rhythm Terms:
- Exogenous Rhythms: are a
direct response to the
environmental cues and are not
internally controlled.
- Endogenous Rhythms: are controlled
by biological clocks. They continue in
the abcense of environmental cues.
However the period may change
slightly from what happens in the
natural envionment
- Zeitgeber: this is the environmental cue
that resets the biological clock so that it
is synchronised with the environment.
Acts as a time keeper.
- Entrainment: This is
when the internal clock
is reset to take up the
period
- Period: this is the length of one complete cycle
of a rhythm. i.e. the time between the start of
one activity and the start of another
- Free Running Period: In laboratory
conditions, if all environmental
cues(zeitgebers) are removed, the
biological clock is a free running period.
- Circa: means approximately or
about.The free running periods of
daily, tidal, lunar and annual rhythms
are not quite the same as
environmental rhythms. Therefore
they are called circadian, circatidal,
circalunar and circannual rhythms.
- Actograms
- Activity is shown in the dark bars
- Each line represents 24 hours
- An actogram is a special graph that
shows the activity of a plant or animal
over the period of the day and many
successive days.This gives a good
indication of when the organism is
active.
- Orientation in Time-Photoperiodism
- Photoperiodism
- Definition of Photoperiodism: is the regulation
of seasonal activity by day length or
photoperiod. eg. the production of flowers in
particular seasons
- Long day plants: the photoperiod exceeds a certain
critical day length(CDL) eg.>10hrs. The days get longer,
why they flower in late spring early summer. An nights
get shorter.
- Short day plants(long night plants): the photoperiod is less
than a certain critical day legth (CDL) eg. <14.5hrs. When days
are getting shorter so flower in autumn. The nights get longer,
continuous darkness is important
- Effect of Pfr on:
- LDP: need minimun amount of Pfr(darkness) to
promote flowering
- SDP: need min amount of Pr(light) to promote
flowering
- Plants use phytochrome to detect the presence or absence of light. This
detector is coupled with a biological clock with an interval timer. When
the dark interval id longer than the light interval it is a short day plant.
When the light interval is longer than the dark interval it is a long day
plant.