The Adaptation Of Organisms Flashcards
What is a behavioural ad of the polar bear?
Ability to stalk seals and knowing where and when to smash through a thick layer of ice to locate their prey
What is a morphological ad of the polar bear?
Thick white fur for camouflage and insulation and small ears and a short tail to reduce heat loss
What is a physiological (biochem) ad of the polar bear?
Can go months w/o food and at this time their met rate can drop to a much lower level- biochem ad that conserves en. Excellent sense of smell to detect their prey
How does temp range affect distr of org?
Many species ad to live within a temp range- range in temp may be seasonal/ between hottest part of day and coldest part of the night . High temp denatures enz/ v low temp water will turn to ice inside cells.
How does water avail affect distr of org?
Org living on land constantly lose water by evaporation. V few org can live in water free areas such as deserts.
Where may xerophytes and hydrophytes be stationed?
Xerophytes are ad to inhabit areas with either little water or water retention by the soil is lim, such as marram grass on sand dunes
Hydrophytes are ad to inhabit areas with a lot of water available
How are mammals adapted for water retention?
Have a waterproof skin and a g.e surface that lies deep within the body; therefore they are protected from loss of water by evaporation to some extent. Therefore, they can survive in extreme conditions more successfully
How does light quality affect the distr of org? e.g red and brown algae
Light ess for phs. Shorter wavelengths of light penetrate deep water. Brown algae can survive if exposed to low intensity red light and therefore live at depths of 10-25 m. Red algae can live in or on the water surface.
Where do species of red seaweed tend to occur?
In zone around and below the low tide mark- they cont light-abs pigment which abs at the blue end of the spectrum. Allows red seaweed to dom a zone inhospitable to most other seaweeds
How does light intensity affect the distr of org?
Nec for phs and with more light the faster the rate of growth.
Most water plants grow close to the shore where light can pen thru the shallow water or float on the surface layers in deeper water.
How does day l affect the distr of org?
Longer day- more phs. In many ecosyst close correlation between day length and temp. L of day can also be crucial for feeding habits. Short night l can be lim for nocturnal feeders.
How does pH value affect the distr of org?
Soil pH infl the avail of certain ions. Opt pH for most plants is 7. Some plants can tol acidic/ alkaline soils. Plants, such as orchids are ad for chalky or limestone rich soil have an opt alk pH.
Heathers and other moorland plants prefer acidic cond
How does the avail of macronutr affect the distr of org?
Macronutr i.e nitrates (for aa) or calcium (calc pectate for middle lamella of plant cell wall form) needed in large quantities by plants.
How does the avail of micronutrients affect the distr of org?
Micronutrients are req in smaller conc and their abundance in soil is dep on type of rock from which the soil was formed.
How does the aeration of soils affect the distr of org?
Most soils contain air in the spaces between the soil crumb. O2 diffuses into the cells in the plant roots for aer resp to occur.
Most soil microbes inv in the decomp of org matter also req O2
Why is plant matter not decomposed in peat bog?
Peat bogs formed from plant matter is usually waterlogged and acidic, cond which inhibit the act of most microog. Therefore, plant matter is not decomposed
How does water content affect the distr of org?
Most British plants are ad for moist well-drained soils. Some are ad to v dry soils (xerophytes) and some to waterlogged soils. Waterlogged soils have v low O2 levels which restrict aer resp in RHC. Waterlogged soils have a low nitrate content due to denitrification which converts nitrates into N2 gas.
What causes zonation of plant species on a riverbank?
Often due to gradients of water availability
What are some e.g of Climatic Factors?
Temp Range
Avail of water
Light Quality
Light Intensity
Day Length
What are some e.g of edaphic factors?
pH values
Avail of nutrients
Aeration of soils
Water content
What are some e.g of biotic factors?
Competition
Predators and Prey
Accumulation of Waste
What do plants compete for?
Light, water, space, minerals and pollinators
What do animals compete for?
Food, mates, breeding sites and shelter from predators
What does interspecific competition allow?
Pop of different species to co-exist in a given habitat as they all occupy different niches. E.g different species of scavengers feedinf of dead carcasses or plant species competing for light on a forest floor.
What does intraspecific competition affect?
More likely to affect the distribution of organisms of the same species as they have similar niches- thus they compete for the same resources
What does the competition exclusion principle?
Two species cannot co-exist if they have the same niche
How do predators and prey affect the distr of org?
Numbers of predators and prey are inf by each other and their numbers fluctuate in a cyclic manner.
Prey no. high= predator no. increase-> more food-> more survive
Too many predators reduce prey no. to point where predator no. start to increase
How may accumulation of waste affect the distr of org? A:In Lag Phase
cells adapt to new env and there is no apparent increase in the pop number
How may accumulation of waste affect the distr of org? B: Exponential Phase
Birth rate exceeds the death rate
How may accumulation of waste affect the distr of org? C: Stationary Phase
The number of births= number of deaths
How may accumulation of waste affect the distr of org? D: The Death Phase
There may be accumulation of toxic waste in the env or lack of food. This leads to death rate exceeding the birth rate and there is a decline in the population
What does ecological niche mean?
Organism’s role w/i the ecosystem. This includes its role in the food chain, its climatic and edaphic req, and its competition with other organisms
What happens when more than one species occupies the exact same ecological niche ?
Interspecific competition often leads to the extinction of one of the species- the competitive exclusion principle
