Biodiversity & Investigating Diversity Flashcards
Define species.
A group of closely related individuals which are capable of interbreeding and producing fertile offspring.
Define population.
All the individuals of a given species living together in the same area at the same time.
Define a community.
All the individuals of all species living together in the same area at the same time
Define habitat.
The place where an organism lives within an ecosystem.
Define niche.
Where an organism lives and what it does (its role). This includes what it feeds on and how it interacts with other organisms and the environment.
Why do only one species occupy one niche in a stable ecosystem?
It reduces competition between species. (interspecific competition)
Define abiotic factors and give examples.
Non-living factors which affect the distribution of an organism. Examples:
temperature, light intensity, wind speed, soil/water pH, water level in soil, slope of land.
Define biotic factors and give examples.
Living factors which affect the distribution of an organism. Examples: competition, predation, disease.
Define ecosystem.
All the living (biotic) and non-living (abiotic) components of a particular area.
Define carrying capacity.
The certain size of population of species that an ecosystem can support.
What is the size of a population determined by?
- Effect of abiotic factors
- Interactions between organisms (biotic factors)
What effect does extreme temperatures have on organisms?
They affect enzymes and therefore the overall metabolic system
- Too cold = enzymes do not have enough kinetic energy to catalyse reactions. An organisms activity will drop and may not be sufficient for survival.
- Too hot = enzymes start to denature. An organisms activity will drop and may not be sufficient for survival. Organisms may also experience problems with excess water loss and dehydration.
What are endotherms?
Animals (birds + mammals) that can use physiological mechanisms to maintain their body temperature (e.g. sweating, shivering)
How can temperature be measured?
-thermometer
- data logger with temperature probe
Why is light important for organisms?
It is needed in photosynthesis. More light = more photosynthesis = more energy = more seeds = plants population grows = more food for plant-eating animals = more food for meat-eating animals.
Why is water important for organisms?
- Acts as a solvent in cells
- Is involved in many reaction (photosynthesis, hydrolysis)
- Acts as a hydrostatic skeleton in many species
How do organisms lose water to the environment?
Evaporation, which can be used in thermoregulation (sweating) or the movement of mineral salts and water through the xylem.
The lower the humidity, ____ water loss via evaporation occurs due to a _____ ________ gradient
more, water potential
How is humidity measured?
Whirling hygrometer or data logger with humidity probe.
Why is pH important for organisms?
- It can affect enzymes and surface proteins. Extreme pH = more enzymes denatured = metabolic rate decreases = death of organism = population decreases. It also would decrease the range of species present in an ecosystem and the availability of mineral salts in soil.
In extreme abiotic factors, ____ species can tolerate them and the ______ population sizes will be.
less, smaller
Define intra-specific competition.
Competition between members of the same species.
What happens if there are two species occupying the same niche?
One species tends to outcompete the other and eventually the niche will be occupied by one species (known as the competitive niche exclusion principle)
Define inter-specific competition.
Competition between members of different species.
Define predation.
When one animal species (the predator) feeds on another animal species (the prey).
What are examples of adaptations predators have to improve their ability to capture prey?
moving at high speeds, venom, secretions
What are examples of adaptations prey have to improve their ability to defend against predators ?
camouflage, protective spines, large peripheral vision