Adaptations to environment B4.1

• What is a habitat?

  A habitat is the natural place where a species, population or community lives.

  It includes geographical features (e.g. deserts), physical features (e.g. temperature) and biological features (e.g. presence of prey)
• What are some characteristics that are used to describe habitats?

  - Biotic factors - Living components

  - Abiotic factors- Non-living components

  - Climate - overall weather patterns

  - Topography - physical features of the land

  - Vegetation type - dominant plant species

  - Availability of recourses - presence of food, water and shelter

  - Human influence - degree of urbanisation, pollution or conservation

  - Species composition - the diversity of the organisms that inhabit the area.
• What are abiotic factors?

  Abiotic factors are the non-living parts of the environment. They include the temperature, light, soil, water, salinity, pH and wind.

  - Abiotic factors influence where organisms can live, and how they survive and reproduce.

  - Therefore, organisms develop structural and physiological adaptations to survive the unique abiotic conditions of their habitats.
• What is adaptation?


  Adaptation in biology refers to the process by which organisms become better suited to their environment. It can also describe a specific trait (structural, behavioural, physiological) that enhances an organism's survival and reproductive success. These traits arise through natural selection, where beneficial genetic variations are passed down over generations.
• What are sand dunes?

  Sand dunes are accumulations of wind-blown sand at the top of beaches. Sand retains little water after rainfall and newly formed dunes contain little water-retaining organic matter. Sand on beach dunes may contain high salt concentrations, hindering water uptake by osmosis.
• What are some challenges that organisms that live on sand dunes may face?

  Plants on sand dunes face the following challenges:

  - Tolerance of sand accumulation

  - Tolerance of high salt concentrations

  - Water conservation
• What are some adaptations of marram grass, and their functions?

  1) Tough sclerenchyma tissue near the leaf surface causes the leaf to roll up - creates a humid chamber that is less exposed to wind.

  2) Waxy cuticle - prevents evaporation

  3) Sunken stomata - creates humid air pockets, reducing transpiration

  4) Deep roots and rhizomes - anchor the plant and absorb water from deep underground

  5) Tough, flexible leaves - resist sand abrasion and strong winds

  6) Sclerenchyma cells - provides structural support during droughts

  7) Frutcans (carbohydrate) accumulation - Increases osmotic potential
• What are mangrove swamps?


  Mangrove swamps develop on the coast where there are sheltered conditions and mud accumulates. The swamps are flooded with seawater at high tide, so the habitats often have high salinity.
• What are some challenges that organisms that live in mangrove swamps may face?

  Plants in mangrove swamps face the following challenges:

  - Waterlogged anaerobic soil that make oxygen uptake difficult

  - High salt concentrations that prevent water uptake
• What are some adaptations of Red Mangrove trees, and their functions?

  1) Salt glands in leaves - excrete excess salt

  2) Pneumatophores (aerial roots) - allow gas exchange in low-oxygen soils

  3) Root epidermis coated in suberin (cork) - reduces permeability to salt, preventing its entry

  4) Vivipary (germination on parent) - ensures seedling survival in salty water

  5) Cable roots - Grow close to the soil surface where there is the most oxygen

  6) Stilt roots - Buttress the tree in the soft mud, as they grow in a downwards arch

  7) Mineral ions and carbon compounds (mannitol) within root and leaf cells - Increase osmotic potential, enabling absorption from the saline environment

  8) Large buoyant seeds - Allow dispersion via ocean currents
• What is species distribution?

  The distribution of a species is where it lives in the world. This is often shown on a map. Distribution is often limited by abiotic factors, as the adaptations of plants and animals suit them for living in some physical environments but not others.
• What are some abiotic factors that affect plant species, and what is this effect?

  1) Light intensity - photosynthesis and growth

  2) Soil pH - nutrient availability

  3) Water availability - determines if a plant is xerophytic (dry habitat) or hydrotropic (wet habitat)

  4) Temperature - enzymatic activity
• What are some abiotic factors that affect animal species, and what is this effect?

  1) Temperature - metabolism

  2) Water - determines if an animal is aquatic or terrestrial

  3) Oxygen levels - limits fish species in stagnant ponds

  4) Light - determines if an animal is nocturnal, diurnal or crepuscular
• What is the range of tolerance?

  Each species survives best within a specific range of abiotic conditions. This is their range of tolerance.

  Adaptations are traits that enhance an organism's ability to survive within specific environmental conditions. These adaptations define the range of tolerance for various abiotic factors.

  Ranges of tolerance are found through investigating correlations between the distribution of a species and abiotic factors. This is investigated via random sampling with quadrats, or sampling across transect lines.

  Too much or too little of a factor can lead to:

  - Stress

  - Reduced reproduction

  - Death
• What is a transect, and how is it used?

  Transect = A straight line or path across a habitat where you sample organisms and abiotic data at regular intervals.

  - Lay out a transect line across a changing habitat (e.g., from a shaded forest into open grassland).

  At each point:

  - Record species presence/abundance

  - Measure abiotic factors (e.g., light, temp, pH using sensors or meters)

  - Create a scatter graph or line chart to correlate species distribution with abiotic changes.
• What is a limiting factor?

  A limiting factor is any environmental condition that restricts the growth, abundance, or distribution of an organism or a population within an ecosystem. It can be abiotic (non-living) or biotic (living), and it determines the maximum potential for survival and reproduction.
• What are coral reefs?

  Coral reefs are marine ecosystems built by colonies of tiny coral animals. They are one of the most biodiverse and sensitive ecosystems on earth, and rely on a symbiotic relationship with zooxanthellae.
• What are zooxanthellae?


  Zooxanthellae are single-celled photosynthetic organisms
• What are the specific abiotic conditions needed in coral reefs?

  1) Water depth - shallow (0-50m) so sunlight can reach the zooxanthellae

  2) pH - above pH 7.8, so calcium carbonate can form coral skeletons

  3) Salinity - 32 - 42 ppt to avoid osmotic issues

  4) Water clarity - clear to allow sunlight to reach the zooxanthellae

  5) Temperature - between 23 and 29 degrees celsius, to avoid coral bleaching
• What is a biome?

  A biome is a group of ecosystems that resemble one another, despite geographical separation. This resemblance is due to similar abiotic conditions, with organisms evolving similar adaptations. Terrestrial biomes include forests, deserts, tundras, grasslands and more.
• How are the types of terrestrial biomes determined?

  The type of terrestrial biome is determined by the temperature and rainfall patterns. Each unique climate combination leads to the development of a specific ecosystem with organisms adapted to survive there.
• What are the characteristics of a desert?

  Temperature - very hot or very cold

  Rainfall - very low

  Example - Sahara
• What are the characteristics of the tropical rainforest?

  Temperature - hot

  Rainfall - high

  Example - Amazon Basin
• What is convergent evolution?

  Each species that lives within a biome is adapted to those conditions. Even unrelated organisms can develop similar traits due to similar abiotic factors. This is known as convergent evolution
• What are the characteristics of grassland?

  Temperature - mild to hot

  Rainfall - seasonal

  Example - North American Prairies
• What are the characteristics of boreal forests?

  Temperature - Cold

  Rainfall - moderate

  Example - Siberian forests
• What are the characteristics of tundras?

  Temperature - very cold

  Rainfall - Low

  Example - Artic regions
• What are the features of hot deserts?

  Hot deserts have high daytime temperatures and cold nights. There is little rainfall and long droughts. Soil development is very limited, with little soil organic matter.

  Organisms must adapt to these extreme abiotic conditions to survive.
• What are some adaptations of the saguaro cactus, and their function?

  1) Thick, fleshy stem - stores a large amount of water

  2) Shallow, wide root system - Quickly absorbs rainfall

  3) Pleated stem - Expands to store more water when available

  4) Spines - Reduces surface area and provides shade

  5) CAM photosynthesis - Reduces water loss as stomata open at night and close at day

  6) Tap roots - absorb water from deep in the subsoil

  7) Vertical stems - avoid overheating from the hot midday sun
• What are some adaptations of the fennec fox, and their function?

  1) Large ears - release excess body heat

  2) Nocturnal behaviour - avoid daytime heat

  3) Light fur - reflects sunlight and provides camouflage

  4) Thick fur on feet - protects against the hot sand

  5) Burrowing - lives underground to stay cool

  6) Long, thick hair - provides heat insulation during cold nights

  7) Ventilation rate increases - facilitates heat loss via evaporation
• What are the features of tropical rainforests?

  Tropical rainforests have high light intensity, high temperatures, no cold season, and a lot of rainfall. Soils tend to be thin and nutrient-poor, due to leaching.

  Organisms must adapt to these extreme abiotic conditions to survive.
• What are some adaptations of the yellow meranti, and their function?

  1) Very tall growth - competes for sunlight above the canopy

  2) Buttress roots - support the tree in shallow, nutrient poor soil

  3) Drip-tip leaves - allows rain to slide off easily

  4) Hard, dense wood in the trunk - supports the tree against wind stress

  5) Smooth trunk - allows rain to slide off easily

  6) Evergreen leaves - carry out photosynthesis all year

  7) Flowers and seeds are produced once every five years - deters animals that eat the seeds
• What are some adaptations of the spider monkey, and their function?

  1) Long arms and legs - facilitate climbing and reaching for fruit

  2) Flexible shoulders - Facilitate swinging from tree to tree

  3) Large hook-like thumbless hands - to grasp branches and vines

  4) Long tail and feet adapted to grasp branches - leaves hands free for fruit picking

  5) Highly developed larynx - for communication in the dense rainforest canopy

  6) Diurnal - sunlight makes movement between branches easier