Biology - B4.1 Adaptation to environment

Definition habitat

The place in which a community, species, population or organism lives

What is included in the descriptions of a habitat?

Geographical location, physical conditions, type of ecosystem

What are adaptations? Type and definition

Abiotic or biotic adaptations

Genetic traits specific to a species, due to evolution

Definition abiotic

non-living

Examples of abiotic variables

Temperature, light intensity, water availability, wind, humidity, pH of soil or water, availability of mineral ions, salinity of soil or water

What is he habitat of Marram grass?

• Dunes at the sea with a lot of wind, sand and parallel to the beach

What are the challenges for Marram grass?

• Must be tolerant to wind

• Sand holds little water

• Dry with high salinity

• Dunes move and vegetation moves

What are adaptations that Marram grass experience?

• The blades are folded so less wind can come to the stomata which are positioned inside the fold

• Waxy cuticle on leaves

• Woody structure when deprived of water

What is the habitat of tall-stilt mangrove?

A mangrove swamp with tropical temperatures, and aquatic environment

Positioned where the saltwater meets freshwater

What are the challenges that tall-stilt mangroves experience?

• Increase in salinity for environment, so must be salt tolerant

• Poor oxygen soil conditions

Adaptations of tall-stilt mangrove trees

• Excrete the excess salt they absorb at the leaves

• Roots come up out of the water and soil to get the extra oxygen

• Large buoyant seeds that can populate and move everywhere

Definition range of tolerance and adaptations relation

The highest abundance of a particular species in the optimum tolerance range and the zone of intolerance

Adaptations give species a range of tolerance, as abiotic variables limit a species’ distribution

How do coral reefs form?

• Colonies of coral polyps which are invertebrate animals

• The polyps secrete a hard calcium carbonate exoskeleton

• This exoskeleton builds up over many years to form the basis of the reef

• Food is obtained through stinging cells but they also photosynthesise using symbiotic algae called zooxanthellae (live within coral)

What are symbiotic algae?

E.g. zooxanthellae in corals

The algae have a mutualistic relationship with the coral

Why do corals have these abiotic conditions in the marine ecosystem?

• Shallow water, so that it’s closer to the light and can get enough light for photosynthesis

• Slightly basic/alkaline pH of around 8 to 8.4, to allow deposition of calcium carbonate

• Quite salty water is the correct osmotic condition for coral and zooxanthellae to survive

• Clear water for light to penetrate for photosynthesis

• Optimum temperatures are between 23-29°C for enzyme function and a fast rate of photosynthesis

What are the abiotic conditions of coral reef habitat?

• Shallow water

• Higher pH, 8.0 to 8.4

• Quite salty

• Clear water

• Optimum temperature between 23-29°C

Definition terrestrial biomes

Areas characterised by specific climate conditions, plant communities and animal species

Temperature and rainfall impacting biomes

For any given temperature and rainfall pattern a particular natural ecosystem type is likely to develop

List of biomes

Tropical forest, temperate forest, taiga, grassland, tundra, hot desert

Climate conditions of tropical forest

High temperature, high amount of rainfall all year round, high light intensity, minimal seasonal variation

Climate conditions of temperate forest

Seasonal temperatures/moderate, moderate to high rainfall, moderate light intensity, warm summers/cold winters for seasonal variation

Climate conditions for taiga

Low to moderate temperatures (-10 to 20 °C), moderate rainfall, low to moderate light intensity, long winters and short cool summers for seasonal variation

Climate conditions for grassland

Warm temperatures, seasonal rainfall, high light intensity, normal seasons

Climate conditions for tundra

Cold temperatures (-30 to 10°C), low precipitation, low light intensity, long winters short cool summers for seasonal variation

Climate conditions for hot desert

Very high temperatures, very low rainfall, high light intensity, minimal seasonal variation

Climate conditions relating to biodiversity

High temperature and high rainfall levels lead to high biodiversity and a lot of plant growth

Examples of adaptations in hot desert

Fennec fox and Saguaro cactus

Adaptations of fennec fox

• Nocturnal, avoids the highest temperatures of the day

• Builds a den underground, for cooler temperatures

• Has long thick hair for insulation

• Has hair on the pads of feat for insulation on hot sand

• Pale coat colour, reflects sunlight

• Large ears to radiate more heat

Adaptations of saguaro cactus

• Wide spreading root system to collect water

• Deep roots to collect water

• Fat stems with storage tissue to conserve water

• Stems vertical to reduce interception of sunlight at midday

• Thich waxy cuticle to reduce transpiration

• Less leaves to decrease surface area and prevent heating

Examples of adaptations of the spider monkey

• Long arms and legs for climbing

• Flexible shoulders for swinging

• Large hook-like hands to grasp branches and pick fruit

• Feet for extra hands, hands for eating fruits

• Long tail to grip branches

• Larynx developed for wide range of sounds, can communicate

• Active in day because then has best vision

Examples of adaptations of yellow meranti

• Grow more than 100 metres, avoid competition for light

• Trunk dense wood for support

• Trunk with support in shallow soil

• Smooth trunk, shed rainwater rapidly

• Evergreen broad oval leaves for year-round photosynthesis

• Enzymes for photosynthesis adopted for higher temperatures

• Not many flowers produced to prevent eating

Transects as a method of gathering information

Can be used to gather data on the distribution of plant or animal species and correlate this data with chosen abiotic factors

Types of transects

• Line transect, organisms that are touching the line at predetermined positions are recorded

• Belt transects, quadrats placed at regular intervals and the abundance of the organisms are recorded

Methods of working with quadrats

• Estimating percentage cover

• Allocating descriptions of each organism according to a scale like the ACFOR scale (A=abundant, C=common, F=frequent, O=occasional, R=rare)