IB DP Biology HL B4.1 Adaptation to environment Flashcards

[q] Ecology

[a] the branch of biology that deals with the relationships between organisms, and their interactions with their physical surroundings.

[q] Organisms

[a] Any individual life form, All organisms have at least one cell.

[q] habitat

[a] The natural home or environment of an animal, plant or other organism.

Habitats must provide an organism with all the resources it needs to survive and reproduce.

Coral Reefs are habitats for several thousand known species.

[q] Describing Habitats

[a] Descriptions of habitats of a species include:

Geographical location is the location where the habitat is found, and may include latitude, longitude, and climate. The geographical location may refer to the localized region of the habitat.

Physical location describes the characteristics of the geographical area where the habitat is found, and may include landforms, water bodies, vegetation and microhabitats.

Type of ecosystem is a broader ecological community, where the species interacts with other species and the abiotic environment.

[q] Species

[a] A group of organisms capable of reproducing with each other to produce fertile offspring.

[q] Population

[a] Consists of one species in one location at one time.

[q] Community

[a] formed by populations of different species living and interacting with each other in a habitat.
Interactions between species include:
● Predator and prey
● Herbivory
● Competition for resources
● Mutualism
● Parasitism

[q] Ecosystem

[a] A location where a community of organisms interact with each other and the abiotic environment.

The abiotic (nonliving) environment includes:

● Air

● Minerals in the soil

● Light

● Climate

[q] Abiotic Environment

[a] Adaptations are any inheritable traits that make an organism better able to survive and reproduce within its habitat. Organisms must be adapted to the abiotic challenges of their environment, if they are to survive and reproduce.
This includes:
● Marram grass, which is adapted to an environment where water is scarce.
● Mangrove trees, which are adapted to living in waterlogged, anoxic soil with high concentrations of salt.

[q] Marram Grass & Xerophytes

[a] Marram grass is a xerophyte that is adapted to survive on sand dunes, where water is scarce.

Xerophytes are plants adapted to surviving in areas with little water available.

[q] Adaptations of Marram Grass

[a] ● Marram grass leaves have a thick waxy cuticle which reduces evaporation of water from the leaf surface.
● The roots of marram grass are long, and go deep into the sand in search of water.
● Marram grass has extensive roots near the surface, which help the sand to retain water.

[q] Mangroves

[a] Mangrove swamps are ecosystems that form on the edge of land and sea.
Mangrove plants are adapted to living in unstable anoxic (low oxygen) soil with their roots surrounded by salt water.

[q] Red Mangrove Trees

[a] Red mangrove trees (Rhizophora mangle) are found in tropical and subtropical mangrove ecosystems.

[q] Adaptions of Red Mangrove Trees

[a] Red mangrove trees are adapted to living in mangrove swamps with unstable soil.
Adaptations of red mangrove trees include:
● Prop roots descend from the trunk and provide the tree with stability.
● A widespread shallow root system provides additional support for the tree.
Red mangrove trees are adapted to living in mangrove swamps with anoxic soil. Anoxic soil has no oxygen present.
Red mangroves are adapted to obtain oxygen for their roots by:
● Aerial roots (known as pneumatophores) grow above the soil. During low tide, gas exchange occurs through open passages. Air is transported to the parts of the roots that are underground.

Red mangrove trees are adapted to living in mangrove swamps with their roots surrounded by salt water. Adaptations include:
● Salt filtration: The plasma membranes of red mangrove roots prevent salt from entering the cytoplasm, while allowing water to enter.
The seeds of red mangrove trees begin to germinate, with the root developing, before the seed falls from the tree.

[q] Shelford’s Law of Tolerance

[a] The law of tolerance was proposed in 1911. According to the law:
● Organisms have optimal survival rates for abiotic factors.
● As an organism moves from areas with optimum conditions, there is a decrease in survival rates.

The law of tolerance proposes a normal distribution of a species in response to a limiting factor.

There are three distinct sections of the graph:

● Optimum range with maximum survival rates

● Zones of stress with reduced survival rates

● Zone of intolerance where organisms cannot survive

[q] Variables that Affect the Distribution of Organisms

[a] ● Temperature
● pH
● Available minerals
● Available light
● Latitude
● Altitude
● Humidity
● Soil content
● Breeding sites
● Aeration of soil
● Climate

[q] Thermal limits of the Pompeii worm

[a] ● Lives in one of the hottest environments on Earth – deep sea hydrothermal vents
● Believed to be one of the most heat-tolerant animals on Earth.
● Live in tubes that they make to protect their bodies from excessive heat.
● A research study removed worms from deep sea vents and used a special pressure chamber to transport them to surface aquaria that were also kept under high pressure.

 The animals were subjected to three different thermal regimes:
• A constant mild 20 degrees exposure
• Heat exposure at 42 degrees
• Heat exposure at 55 degrees
● This was followed by a 3-hour recover period at 20 degrees.
● The hear exposures lasted 2 hours
● Cells were removed from the animals to establish the amount of cell death.
● The survival of all the animals was established by observing movements, just before sampling their body fluid for cells.

[q] Belt Transects

[a] Belt transects are used to investigate the relationship between the distribution of a species in relationship to an abiotic factor. Transects are useful for investigating the distribution of plants and sessile animal species.

The belt transect method is used when there is a gradual change from one side of a habitat to another, like the change in light between the outer edges of a forest to the centre.

A transect is a path along which you count and record occurrences of the species of study (e.g. plants) within quadrats.

It requires an observer to move along a fixed path and to count occurrences of species along the path.

[q] Investigating the Range of Tolerance

[a] Belt transects can be used to investigate changes in species distribution as an abiotic factor changes, such as:
● Change of distance from low tide or lake edge (Abiotic factor – time submerged by water).
● Change of altitude as you move up a steep hill (Abiotic factor – altitude).
Change of light intensity as you enter a woodland (Abiotic factor light intensity).

[q] Measuring Abiotic Factors

[a] Abiotic variables that could be measured include:
● Temperature
● Light intensity
● Soil pH
Students should collect data for their investigation of abiotic factors on species distribution in either:
● A natural habitat, which have no species cultivated by humans.
● A seminatural habitat, which have been influenced by human activities, but most of the species in the habitat are wild species, and not cultivated by humans.

[q] Coral Reefs

[a] Coral reefs are one of the most biodiverse ecosystems. Coral reefs are formed by sessile animals, which have a mutualistic relationship with Zooxanthellae.
The formation of coral reefs require specific abiotic conditions for coral and zooxanthellae to survive.

[q] Development of Coral Reefs

[a] The following factors affect the growth of coral:

● Water clarity: The zooxanthellae that live within the coral are photosynthetic and require sunlight. Coral require clear water, so that the light can reach the zooxanthellae for photosynthesis.

● Water depth: Light is rapidly absorbed by seawater and does not penetrate to great depths. Coral grows best at depths of around 50m, though it varies according to the species of coral. The zooxanthellae provide coral with most of their nutrients, and require light for photosynthesis.

● Temperature: Corals thrive in a water temperature range between 16°C and 34.5°C, though it depends on the species of coral. Low temperatures kill the coral, and high temperatures cause the zooxanthellae to be released from the coral, resulting in death of the coral.

● pH: Corals survive best within a pH range of 8.0 to 8.3. Ocean acidification is a threat to coral reefs.

● Salinity: Coral can tolerate a salinity range of 23 – 42 ppt.

[q] Biomes

[a] Biomes are large naturally occurring communities of organisms occupying a major habitat.

[q] Climate and Terrestrial Biomes

[a] Whittaker’s Climograph predicts the terrestrial biome found in a location according to mean annual temperatures and mean annual precipitation.

[q] IB Biomes to familiarize

[a] IB Biology students should be familiar with the climatic conditions of the following biomes:
● Tropical forest
● Temperate forest
● Grassland
● Hot desert
● Taiga
● Tundra

[q] Tropical Forest

[a] Tropical forests have high rainfall and high temperatures all year round.

[q] Temperate Forests

[a] Temperate forests have hot summers and cold winters, and a moderate amount of rainfall.

[q] Grasslands

[a] Temperatures vary depending on the location of the grasslands, but they all have relatively low rainfall.

[q] Hot Desert

[a] Hot deserts have hot days and cold nights.
All deserts have very low rainfall.

[q] Taiga

[a] Taiga have very cold, snowy winters, and warm humid summers.
The taiga has low precipitation, which is often snow.

[q] Tundra

[a] The tundra is frozen for most of the year, with very short summers.
Precipitation is very low.

[q] Biomes and Convergent Evolution

[a] Convergent evolution is the independent evolution of similar features in species producing analogous structures.

[q] analogous

[a] comparable

[q] Adaptations of Desert Plants

[a] Desert plants have adaptations that allow the plants to survive high temperatures and a scarcity of water.

Some adaptations include:

● Succulence: Many desert plants have fleshy stems and leaves for water storage.

● Reduced leaf surface: Reduced leaf surfaces, such as spines on cacti, reduce water loss through transpiration.

● Deep root systems: Allow desert plants to access groundwater, as well as widespread root systems near the surface to collect any rainfall.

● CAM physiology: A type of photosynthesis, where stomata remain closed during the day to reduce water loss by transpiration. The stomata open at night when it is cooler.

● Thick waxy cuticles: Reduces water loss through evaporation from the plant.

[q] Adaptations to Desert Ecosystems

[a] Plants and animals that live in deserts have evolved various adaptations to survive the high temperatures and lack of water.

[q] Saguaro Cactus

[a] Saguaro cacti are xerophytes which live in deserts. Adaptations of saguaro cacti include:
● Thick waxy cuticles prevent water loss.
● Spines are modified leaves which reduce surface area for transpiration of water. The spines also provide protection from predators.
● Water storage tissue allows cacti to survive without rainfall for a long time.
● A widespread root system, that allows absorption of any available water.

[q] Adaptations of Desert Animals

[a] Desert animals have evolved physiological and behavioural adaptations to surviving in deserts.

Adaptations include:

● Nocturnal Behaviour: Many desert animals are active at night when it is cooler, reducing water loss. The animals burrow underground during the hottest part of the day.

● Efficient water conservation: Many desert animals produce concentrated urine. Many insects and birds produce uric acid rather than urine, which reduces water loss.

● Efficient Metabolism: Desert animals have metabolic adaptations which allow them to cope with limited food sources, such as low metabolic rates, or the ability to store fat.

● Camouflage: Desert animals are often camouflaged to avoid being seen by predators or prey.

[q] Camels

[a] Camel adaptations to living in deserts include:

● Water conservation: Camels produce very concentrated urine, and their intestines extract a lot of water from faeces.

● Fat storage: Camels store fat in their humps. The fat can be metabolized to produce energy and water when food and water are scarce.

● Large surface area to volume ratio of their bodies: The large surface area allows for efficient heat loss.

● High temperature tolerance: Camels can withstand high body temperatures, reducing the need for sweating to cool themselves down.

● Long Legs: Keep the camel’s body above the hot sand.

● Long nasal passages: The nasal passages trap and reabsorb moisture from exhaled air.

● Broad feet: The broad, padded feet of camels allow then to efficiently walk over sandy terrain.

[q] Adaptations of Plants in Tropical Rainforests

[a] Plants in tropical rainforests compete for light and scarce nutrients in the soil. Plants have a range of adaptations to survive in tropical rainforests which include:

● Buttress roots: Buttress roots are large overground roots which provide stability, and absorb nutrients from the shallow topsoil.

● Drip tips: The leaves of many plants have elongated, pointed ends, which allows water to run off quickly, preventing waterlogging and the growth of fungi.

● Epiphytes: Grow on other trees, using them for support. They obtain nutrients from the air and rain.

● Lianas: Lianas are vines that grow up the trunks of tall trees to reach the light.

● Mutualistic relationships: Many plants have developed mutualistic relationships with animals for pollination and seed dispersal.

[q] topsoil

[a] the top layer of soil

[q] Adaptation of Dipterocarp Trees

[a] Red meranti (Shorea leprosula) are dipterocarp trees found in Southeast Asian tropical rainforests.

The red meranti has the following adaptations:

● Tall tree: It can access sunlight for photosynthesis as it reaches the canopy layer of the rainforest.

● Fast growth rate: The growth rate allows it to reach the canopy quickly.

● Buttress roots: The buttress roots are overground, and prevent the large tree from toppling.

● Large Leaves: red meranti trees have a broad and dense canopy with large leaves to maximize light absorption for photosynthesis.

● Large quantities of fruit: The large number of fruit increases the chance of reproductive success. Animals like orangutans consume the fruit, helping with seed dispersal.

● Chemical defenses: The leaves of the red meranti contain toxins to deter insects from eating them.

[q] Adaptations of Animals in Tropical Rainforests

[a] Tropical rainforests are the most biodiverse terrestrial biome. Many animals are adapted to live in the canopy of the rainforest. Adaptations of some animals include:

● Arboreal adaptations: Adaptations which allow the animal to live in the tree canopy include prehensile tails, grasping hands and feet, and strong limbs.

● Acute senses: Many animals in the rainforest have highly developed senses of sight, hearing and smell which allow them to navigate through the vegetation, and locate food sources and predators.

● Camouflage: Camouflage can help predators to ambush prey, or prey animals to avoid predators.

[q] Sumatran Orangutans

[a] Sumatran orangutans are adapted to live in the canopy of Sumatra’s tropical rainforests.

Adaptations include:

● Long arms and grasping feet: The long arms and feet allow orangutans to move from branch to branch in the tree canopy.

● Opposable fingers and toes: The opposable fingers and toes allow orangutans to grasp tree branches, and manipulate tools.

● Colour vision: Colour vision allows orangutans to recognise edible fruits and potential predators.

● Camouflage: The reddish-brown hair allows them to blend into the forest canopy.

● Intelligence: They are capable of using tools to obtain food.

● Strong jaws and teeth: They use strong jaws for eating unripe fruit.

[q] Climograph

[a] A plot of the temperature and precipitation in a particular region.

[q] Seminatural Habitat

[a] habitats that are altered

[q] Mutualism

[a] A relationship between two species in which both species benefit.

[q] Parasitism

[a] A relationship between two organisms of different species where one benefits and the other is harmed.

[q] Commensalism

[a] A relationship between two organisms in which one organism benefits and the other is unaffected.

[q] What do species need to adapt to?

[a] They need to adapt to the habitat!
Habitat is the place in which a community, species, population or organism lives.
Includes the geographical and physical location.
The type of ecosystem in that area.

[q] What are the abiotic factors affecting biomes?

[a] Temperature and rainfall affect distribution of biomes.
Similar ecosystems will arise in those areas.

[q] What are the climate conditions for ecosystems?

[a] Communities looks very similar because of convergent evolution.
For Tropical Forests you have high temp and high rainfall.
For Temperate Forests you have moderate(fluctuating ) temp, medium rainfall.
For Taiga you have Low temp, low/medium rainfall.
For Grassland you have fluctuating temp, low rainfall.
For Tundra you have really low rainfall.
For Hot Desert* you have high temp, really low rainfall.

[q] What are some examples of adaptations to life in hot deserts and tropical rainforests?

[a] Hot Desert-Camel-Hump to store fat to use as water.
Hot Desert-Desert Tortoise-Digs burrows – has special feet to dig burrows.
Hot Desert- Saguaro Cactus-Thick waxy coating, reduced leaves, hard spines.
Tropical Rainforest-Tiger-Striped coat.
Tropical Rainforest-Okapi-Dark body, stripes.
Tropical Rainforest-Drip tips-Climbing plant, aerial roots, pointy leaves to drain excess water.

[q] What are some examples that affect species distribution?

[a] Sugar Maple – Temperature must be between -18 degrees C and 27 degrees C.
Tropical fish – temp ranges from 60-85 degrees F.

[q] What is the range of tolerance?

[a] Range of tolerance acts as a limiting factor of population size.
Shifts outside of that range lead to decreased population size.
Relates back to D4.1.4 abiotic factors as selection pressuresRange of tolerance acts as a limiting factor of population size.
Shifts outside of that range lead to decreased population size.
Relates back to D4.1.4 abiotic factors as selection pressures.

[q] Explain Coral Reefs

[a] Coral reefs are very sensitive.
Require very specific conditions for formation.
Temperature – 23-29 Degrees C.
Salinity – high salt levels 32-42 parts per thousand.
Light – clear water for high levels of light.
pH – need a stable pH above 7.7.
Water depth – most corals occur within less than 25 m of water depth.

[q] Sand dunes

[a] American beachgrass – The plant has a deep, strong and extensively creeping rhizome.
Allows it to survive in sandy and salty environments.

[q] What are mangroves?

[a] Many mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water.

This tangle of roots allows the trees to handle the daily rise and fall of tides, which means that most mangroves get flooded at least twice per day.

The roots also slow the movement of tidal waters, causing sediments to settle out of the water and build up the muddy bottom.

[q] B 4.1.1 Habitat as the place in which a community, species, population, or organism lives.

[a] Habitat – the place in which a community, species, population, or organism lives.
Definitions:
Community – an interacting group of various species in a common location; all the populations that live together.
Species – a group of organisms that can breed and produce fertile offspring.
Population – all of the members of one (the same) species that interbreed and live in the same place at the same time.
Organism – a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis.

[q] B 4.1.2 Adaptations of organisms to the abiotic environment of their habitat.

[a] Example 1: Sand dune grasses
– little organic matter to retain water (sand does not hold water like other soil types).
– high salt content in water (the water is hypertonic to the cells of the plant; the water moves out of the plant instead of into it).
Lyme grass:
– thick waxy cuticle (hydrophobic; helps the plant hold onto its water).

– stomata in indentations (reduces the lost of water; less movement of water by air currents).
– rolled leaves (*does the same thing as stomata in indentations; stomata are located on the bottom of the leaf; helps the plant hold onto its water).
– tough sclerenchyma (cell that provides structure for a plant) to prevent wilting (supports living tissues so that they do not get crushed).
– rhizomes (acts like a root, but are stems) that grow up as sand accumulate as well as down (allows the plant to not get buried too deep by the sand).
– accumulation of carbohydrates (fructans) in roots and leaves (energy source; raises the osmolarity of the cell so that water will still diffuse in despite the salt content).

Example 2: Trees in Mangrove swamps
– waterlogged soil and high salt content (soil not stable; lack of oxygen – hyptertonic).

– salt glands in leaves (excrete/move salt out).
– root coated in cork to reduce permeability to salt (prevents some of the salt from entering).
– roots have pneumatophores (allows gas exchange; above the water line; grows up).
– stilt roots grow out in an arch (creates support so that they do not fall over).
– large buoyant seeds (allows seeds to stay on the surface of the water so they can travel somewhere with a lower water level).
– accumulation of mineral ions and carbon compounds in the root and leaf cells (osmolarity; carbon compounds used for energy;

sacrificing a root or leaf so that the rest of the plant can survive – taking in mineral ions in one root or leaf; plant could not survive if all parts had the tonicity).

[q] B 4.1.3 Abiotic variables affecting species distribution

[a] Plants
– temperature, water availability, light intensity, soil pH, soil salinity
Affects/Consequences:
Water availability – plants need water for photosyntheses, to transport materials, for cell structural support
Temperature – high temperatures leads to evaporation; low temperatures leads to slow growth
Light intensity – more light = more photosynthesis
Soil pH – affects how much hydrogen ions are present;

hydrogen ions react with mineral ions = affects plants ability to take in minerals, also affects the plants pH and the type of water taken in (acidic soil take sin acidic water)
Soil salinity – limits water intake from soil

Animals
– water availability, temperature
Affects/Consequences:
Water availability – animals need water for hydration and digestion of food
Temperature – too high temperatures lead to heat stroke, dehydration, hyperthermia (abnormally hot body temperature);

too low temperatures lead to hypothermia (abnormally cold) body temperature)
Plants and Animals Connection(s):
– if temperatures are outside a certain level, plants could die, leaving animals with low resources (shelther, food, etc.)
– abiotic variables affecting the distribution of plants creates different biotic problems for animals.

[q] B 4.1.4 Range of tolerance of a limiting factor

[a] Application of skills
– Sample across the range of a limiting factor for a population.
Such as looking at a certain species and how well that species is living across different light intensities, salinity, soil pH, water availabilities, temperatures, etc.
– Use a transect.
A straight line that cuts through a natural landscape so that standardized observations and measurements can be made.

[q] B 4.1.5 Conditions required for coral reef formation.

[a] – Water depth: less than 50m
if deeper, photosynthesis could not occur because less light would be available.
– pH: above 7.8 (mild basic)
must be basic so that the exoskeleton (made of calcium carbonate) of the animals that live in the coral will not dissolve due to being in water that is too low in pH (acidic).
– Salinity: 32 to 42ppt
– Clarity: clear
for light intensity = for photosynthesis for plant life (the coral’s food/prey).
– Temperature: 23 to 29°C
all the organisms that live in the coral reef have a very narrow tolerance range for temperatures.

[q] B 4.1.6 Abiotic factors as the determinants of terrestrial biome distribution.

[a] What IB considers all of the major terrestrial biomes:
– Tundra
– Taiga/Boreal forest
– Temperate grassland/cold desert
– Chaparral/Shrubland
– Temperate deciduous forest (Our biome)
– Temperate rainforest
– Subtropical desert
– Tropical seasonal forest/savanna
– Tropical rainforest
Important abiotic factors (used in graph):
– annual precipitation (cm)
– average annual temperature (°C)

Determinant – an element that identifies or determines the nature of something or that fixes or conditions an outcome.

[q] B 4.1.7 Biomes as groups of ecosystems with similar communities due to similar abiotic conditions and convergent evolution.

[a] Biome – a group of ecosystems with similar communities due to similar abiotic conditions and convergent evolution.

[a] Hot desert
Saguaro (plant – cactus):
– widespreading root system with deep tap root (tap root allows the plant to get any water that’s down deep and also helping it anchor into the soft/sand soil;

the wide network of roots means that it captures shallow water from a large area)
– fat stems (to store water)
– vertical stems (allows the plant to capture water, reduces the amount of the plant that is in direct sunlight for the evaporation of water;

allows more soil area to be available for water to be absorbed; creates a zone of shadow – part of the ground shielded by shade – less water evaporating from the soil in that area)
– spines (protection from predators)
– CAM metabolism (a way for a plant to chemically react carbon dioxide into a compound that it can the use to carry out photosynthesis;

cannot store carbon dioxide but can take it in – at night through the stomata – and convert it into a carbon substance that can then be converted back when its necessary for photosynthesis – during the day)
Fennec fox (animal):
– nocturnal (active during the night; cooler temperatures)
– undergroud den (cooler temperatures)
– pale, long thick hair (absorbs less light; blends in with its surroundings better)
– large ears (help cool down faster)

Tropical rainforest
Meranti (plant):
– grows to over 100m high (compete for sunlight)
– hard dense, smooth trunk (withstand mass as it grows taller)
– broad oval, evergreen leaves with pointed tips (more surface area for capturing sunlight for photosynthesis;

no reason to lose leaves – not a period where they will not life; pointed tips allow water to run off – because the weight of the water could damage the leaves and allows water to run down to its roots)
– heat tolerant enzymes
– large quantities of seeds only 1 out of every 5 years (need to grow to the point that the plant is making room for their offspring;

takes time for them to grow tall – higher the plant, the further its offspring will spread)
Spider monkey (animal):
– long arms and legs
– flexiable shoulders
– large hook-like-hands
– long griping tails
First four points: helps navigate through an area with lots of large trees.
– highly developed larynx (to communicate across large distances to one another)
– diurnal (active during the day; days are very long)
– breeding year round (no reason not to – does not have to worry about the winter killing off the offspring;

conditiond are pretty much the same)

[x] Exit text