Biology - 16 Adaptations, Interdependence and Competition

Community

all the different populations that live together in an area

Ecosystem

a community of organisms and their abiotic environment

Biotic

living

Abiotic

Non-living

Interdependence

mutual dependence between things

Population

group of individuals of the same species that live in the same area

Stable community

where all the species and environmental factors are in balance so that population sizes remain fairly constant

Abiotic factors [7]:

- light intensity
- temperature
- moisture levels
- soil pH and mineral content
- wind intensity and direction
- oxygen availability
- carbon dioxide availability

How does light intensity affect communities? [3]

- light limits photosynthesis and therefore plant growth
- plants adapted to low light levels may have broader leaves
- breeding cycles link to day length and light intensity

How does temperature affect communities? [3]

- temperature limits photosynthesis and therefore plant growth
- plants in cold climates are smaller and sparser
- this affects herbivores and therefore affects carnivores

How do moisture levels affect communities? [2]

- less water means little to no life
- desert plants and animals are adapted to dry conditions

How does soil pH and mineral ions affect communities? [3]

- a low pH inhibits decay and therefore slows the decay cycle
- many mineral ions are needed for plant growth
- some plants have become carnivorous to attain ions

How does wind intensity and direction affect communities? [2]

- plants transpire faster in windy areas
- shape of trees and landscapes are different in windy areas

How does oxygen availability affect communities? [2]

- the proportion of oxygen in air varies very little
- most sea life cannot live in low-oxygen water

How does carbon dioxide availability affect communities? [2]

- carbon dioxide limits photosynthesis and therefore plant growth
- can affect distribution of animals e.g. mosquitos

Biotic factors [4]:

- food availability
- new pathogens or parasites
- new predators
- interspecific competition

How does food availability affect communities? [2]

- abundance of food causes population growth
- scarcity of food causes population stagnation or decline

How do new pathogens or parasites affect communities? [2]

- organisms have no resistance to a new pathogen or parasite
- populations may be damaged or wiped out

How do new predators affect communities? [2]

- organisms have no defences against new predators
- populations may be damaged or wiped out

How does interspecific competition affect communities? [2]

- new species may outcompete others
- this may result in inability to successfully breed in damaged populations

Interspecific

between different species

Intraspecific

within a species

Abundance

a great or plentiful amount

Distribution

the arrangement of a feature in space

Quadrat

square frame used for sampling in field work

Sample size

the number of times a measurement is replicated in data collection

Quantitative sampling

records the number of organisms rather than just the type

Transect

to cut across something

Competition

the struggle between organisms to survive in a habitat with limited resources

What do animals compete for? [3]

- food
- territory
- mates

Food competition [3]:

- between herbivores that eat the same plant
- between carnivores that eat the same prey
- between prey animals that are eaten by the same predator

Territory competition [2]:

- territory is needed for breeding and feeding the offspring
- urine or faeces is used to mark territory

Mate competition [2]:

- in some species, males fight to mate with multiple females
- in others, males display themselves, such as birds and lizards

Successful competitors [4]:

- better at finding food or mates than other members of its species
- better at finding food than members of local species
- able to breed successfully
- avoids competition with other species

What do plants compete for? [4]

- light
- water
- mineral ions
- space

Adaptations to cope with competition [4]:

- flowering early in the year when tree cover is minimal
- having different (deeper or shallower) roots than local species
- growing taller to reach light or having broader leaves to increase surface area
- tendrils or suckers that allow them to climb

Seed dispersal methods [4]:

- seeds with flight capability
- seeds carried by vectors after eating fruit
- explosive seed pods
- utilising flowing water

Adaptation

trait that helps an organism survive and reproduce

Epiphyte [2]

- uses other plants for support
- collect water and nutrients from air with specially adapted leaves

Saguaro cactus [3]

- flowers open at night and have strong perfume and lots of nectar
- flowers stand on top of cactus
- bats feed on nectar and pollinate flowers

Herbivore teeth

flat teeth for grinding plants

Carnivore teeth

pointed teeth for tearing flesh

Adaptation to sea water

some seabirds and iguanas, as well as mangrove trees, remove excess salt from the body via a gland

Adaptation to extreme winters

animals and plants produce a chemical that acts as an antifreeze to prevent freezing water damaging cells

Adaptation of plants to live on water

large air spaces in the leaves to float so they can photosynthesise

Extremophile

organism that grows under extreme or harsh conditions

Archaea

one of two prokaryotic domains, the other being bacteria

Thermophile

an organism that has adapted to living in very high temperatures (45 - 80°C) via special enzymes that do not denature

Saline extremophile

bacteria with adaptations to the cytoplasm so that water does not exit the cell by osmosis

Types of adaptations [3]:

- structural (i.e. shape, colour)
- behavioural (i.e. migration, basking, tools)
- functional (i.e. delayed embryonic implantation, antifreeze)

Adaptations of animals in cold climates [3]:

- small SA:V to reduce loss of heat
- small SA on thin-skinned areas
- insulation (blubber or fur)

Camouflage [2]

- structural adaptation
- important to predators and prey

Adaptations of animals in desert climates [4]:

- kidneys that retain a lot of water and produce very concentrated urine
- more active at cool times (morning and evening)
- large SA:V (small animals)
- large ears to transfer energy to surroundings

Adaptations of plants in desert climates [4]:

- broad leaves to collect dew and funnel to roots
- leaves with a small surface area to reduce loss of water
- curled leaved to hold a pocket of moist air and reduce water loss
- thick cuticle to reduce water loss

Marram grass

tightly curled leaves to reduce surface area for water loss and survive in dry conditions

Butcher's-broom

survives in dry, shady conditions under trees as leaves are really flattened stem, reducing water loss

Cacti

leaves are reduced to needles to discourage animals from eating and reduce the surface area

Collecting water in dry conditions [2]

- roots that spread over a wide area
- roots that penetrate very deep

Storing water in dry conditions

fleshy leaves, stems or roots contain tissue adapted to store water