Ecology Flashcards
Unit 4
Define Habitat
The place where an organism lives. It’s geological location, but more specifically the type of location inhabited (physical conditions)
What are the three different types of adaptations for predators to find, catch and kill prey (examples for each)
- Physical: specialized teeth for piercing and tearing, great eyesight
- Chemical: Venom, pheromones that mimic other species mating scents
- Behavioural: Ambush techniques learned from practice, speed and strenght to overpower
What are the three different types of adpatations for PREY animals to avoid getting eaten? (with examples for each)
- Physical: Camouflage
- chemical: Toxic substances and warning signs through coloration
- Behavioural: Swim or move in tight groups or packs, flee with speed or hide
within three different types of Prey and predator’s adaptations, what can change the fastest?
Behavioural adaptations!
Within three different types of prety and predator’s adaptations, what changes (adapts) the slowest? (elaborate, with reasoning)
Chemical adaptations, becuase new enzymes may be needed or new ways of regulating enzymes, which may take millions of years.
Define Forest canopy
Upper layer of the forest, a place where a tree (tallest) is not affected by the shades of other trees.
What are soem plant’s strategies to obtain light?
- Leading shoot that grows to great heights (be tall)
- Plants grow on branches of other trees
What are epiphytes
They are type of plants which grow on the trunks and branches of trees, it has no roots to the soil
How does epiphytes obtain moisture?
From the plants it grows on, like moss
What do strangler epiphytes do to obtain light?
They climb up the trunks of other trees and out grow their branches so it shades out the leaves of the host tree, causing the death to the host tree
What are some adaptations of plants which grow in the shade (short plants)?
The shade plants are good at absorbing wavelenghts of ligth which are still available.
Define fundamental niche
Area within an organism’s range of tolerance (The biotic and abiotic ranges the organism can live in).
Define realized niche
The actual range that a species occupies due to competition, excluding them from prats of it’s fundamental niche
What would happen to species without any competitors (in relation to fundmental and realized niche)?
Species living without competitors, would occupy the whole fundamental niche.
What when two species have overlapping fundamental niches?
One speices will outcompete the other in all or parts of its fundamental niche.
What happens to the out competed species when two sepies have overlapping fundamental niches?
The outcompeted species will not have a realized niche and will be competitvely excluded from that ecosystem
What will happen to the outcompeted species during competitive exlusion?
It will lead either to the extinction of the weaker compettitor or to an evolutionary or behaviour shift toward a different ecological niche
According to ecological theory, what should be unique for each species to survive? (in terms of realized niches)
To survive, each species must have a realized niche that differes from all other species
Define populations
A group of individual organisms of the same species living in the same area at the same time
can members of the same population interbreed?
Yes, normally ithey can interbreed with each other
How are populations normally seperated by?
Population are often separated by geographical barriers (water, mountain)
What is the difference between speices and population?
Species are organisms that can interbreed, while population are members of a single species
Can we count every organisms? Why?
No, it is nearly impossible since organisms camouflage, move and haveare spread over vast areas.
What is random sampling?
Where every mmeber of a population has an equal chance of being selected.
How do we reduce sampling error when random sampling?
By avoiding unconscious bias (i.e. use a random number generator on a phone app).
what is a method of quadrat sampling?
Quadrat sampling involves repeatedly placing a quadrat frame habitat and recording the number of individuals each time it is placed.
When is the use of quadrat sampling appropriate for estimating population size?
It is only appropriate for estimating population size for sessile organisms that does not move
When is the use of capture-mark-recapture method appropriate for estimating population size?
When estimating the population size for motile organisms which move around constantly
What is Lincoln Index?
It is a formula used to estimate population size for capture-mark-release-recapture method
What is formula of Lincoln Index?
Population size estimate = (M x N) / R
M: Number of individuals originally caught and marked
N: Total number of individuals recaptured
R: The number of marked individuals recaptured
What happens when resources become scarce?
The members of a population will compete for it
Define carrying capacity
The maximum size of a population that an environment can support
Define limiting factor
A factor which limits the size of a population. Anything that limits a population’s size and solows or stops it from growing.
What happens when there are too few resources?
it will lead to individuals being unable to get basic needs and die, reducing population size
What are the typical limiting factors in ecosystems for plants?
water
light
soil nitrogen
what are typical limiting factors in ecosystems for animals?
water
space (for breeding)
food or space to obtain food
dissolved oxygen
What is one of the reasons for the fluctuating of population’s size?
The population could fill an ecological niche which hasn’t been occupied before and then ecological changes will cause a decrease
How can population size remain overally stable?
Due to negative feedback control
What are the two types of factors which can increase or decrease populations
Density independent factors
Density dependent factors
Define density dependent factors
factors which have an increasing effects as populations grows larger.
What does density dependent factors do?
They push populatin towards its carrying capacity. They are the basis of negative feedback mechanisms
Why is the density dependent factors basis for negative feedback?
They reduce larger populations and allow smaller populations to increase
what is density independent factors
same effect not matter the population level
What does the PANDA stand for, for density dependent factors?
P- Predators
A- Availability of resources
N- Nutrient supply
D- Disease
A- Accumulation of wastes
What does the PAW sand for, for density independent factors?
P- Phenomena (natural disasters)
A- Abiotic factors (temeprature, CO2 levels)
W- Weather conditions
What does reproduction tends to cause?
An exponential growth in populations