Unit 9 Conservation (Part 2) B4.1 Adaptation to Environment Teaching Notes PDF

B4.1 Adaptation to environment Student Notebook 1  Learning Objectives B4.1 Adaptation to environment SL/HL: 3 hours Guiding questions How are the adaptations and habitats of species related? What causes the simil...

B4.1 Adaptation to environment Student Notebook 1  Learning Objectives B4.1 Adaptation to environment SL/HL: 3 hours Guiding questions How are the adaptations and habitats of species related? What causes the similarities between ecosystems within a terrestrial biome? Understandings 🙂 🙁 B4.1.1—Habitat as the place in which a community, species, population or organism lives A description of the habitat of a species can include both geographical and physical locations, and the type of ecosystem. B4.1.2—Adaptations of organisms to the abiotic environment of their habitat Include a grass species adapted to sand dunes and a tree species adapted to mangrove swamps. B4.1.3—Abiotic variables affecting species distribution Include examples of abiotic variables for both plants and animals. Should understand that the adaptations of a species give it a range of tolerance. B4.1.4—Range of tolerance of a limiting factor. Application of skills: Should use transect data to correlate the distribution of plant or animal species with an abiotic variable. Should collect this data themselves from a natural or semi-natural habitat. Semi-natural habitats have been influenced by humans but are dominated by wild rather than cultivated species. Sensors could be used to measure abiotic variables such as temperature, light intensity and soil pH. B4.1.5—Conditions required for coral reef formation. Coral reefs are used here as an example of a marine ecosystem. Factors should include water depth, pH, salinity, clarity and temperature. B4.1.6—Abiotic factors as the determinants of terrestrial biome distribution Should understand that, for any given temperature and rainfall pattern, one natural ecosystem type is likely to develop. Illustrate this using a graph showing the distribution of biomes with these two climatic variables on the horizontal and vertical axes. B4.1.7—Biomes as groups of ecosystems with similar communities due to similar abiotic conditions and convergent evolution. Should be familiar with the climate conditions that characterise the tropical forest, temperate forest, taiga, grassland, tundra and hot desert biomes. B4.1.8—Adaptations to life in hot deserts and tropical rainforest. Include examples of adaptations in named species of plants and animals. 2 each objective and are happy with the content by adding a tick in the column marked sure about understandings then make a tick in the column marked 🙂 As you work your way through each learning objective in the booklet, indicate that you have completed 🙁. If you are not and note down any questions that you many have in the space provided. It’s your responsibility to approach your teacher and ask for clarification on any objectives that you do not understand. Space for questions: ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… 3 ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………… 4  GLOSSARY Key words and Phrases Habitat: The place in which a community, species, population, or organism lives. It can include geographical and physical locations, as well as the type of ecosystem (e.g., forest, desert). Abiotic Environment: Non-living factors in a habitat, such as temperature, light, and soil composition. Adaptation: A feature or characteristic that allows an organism to survive and reproduce in its environment. For example, a grass species adapted to sand dunes or a tree species adapted to mangrove swamps. Abiotic Variables: Non-living factors that affect species distribution, such as temperature, pH, salinity, light intensity, and moisture levels. Different species have different tolerance ranges for these factors. Range of Tolerance: The range of an abiotic factor (such as temperature or pH) within which an organism can survive. Species are typically distributed according to their tolerance for various abiotic factors. Limiting Factor: An environmental condition that limits the growth, distribution, or abundance of an organism or population in an ecosystem. Water Depth: Coral reefs typically form in shallow waters where sunlight can penetrate. pH: Coral reefs require a slightly alkaline pH (around 8.0–8.4). Salinity: Coral reefs thrive in waters with a stable salinity range of 32–42 parts per thousand (ppt). Clarity: Coral reefs need clear water to allow sunlight to reach the corals, which are dependent on photosynthetic algae. Temperature: Corals require water temperatures between 23°C and 29°C for optimal growth. Terrestrial Biomes: Large regions defined by similar abiotic factors, primarily temperature and rainfall, that result in specific ecosystems like tropical rainforests, grasslands, or deserts. Temperature and Rainfall: The two main abiotic factors that determine the type of biome that will develop in a particular region. Biome: A large community of plants and animals that occupy a distinct geographical area and are adapted to its climate. Convergent Evolution: The process by which different species evolve similar traits, even though they have different evolutionary ancestors, due to similar environmental pressures. Adaptation to Deserts: Adaptations in desert species may include water conservation mechanisms, such as cacti storing water in their tissues or desert animals being nocturnal to avoid heat. Adaptation to Tropical Rainforests: Adaptations in rainforest species may include large leaves for capturing sunlight in the shaded forest floor or buttress roots to support tall trees in nutrient-poor soils. 5 Habitats are where organisms live B4.1.1—Habitat as the place in which a community, species, population or organism lives A description of the habitat of a species can include both geographical and physical locations, and the type of ecosystem. https://app.kognity.com/study/app/ibdp-biology-slhl-2025-pc/sid-422-cid-242422/book/adapta tions-of-organisms-to-a-habitat-and-species-id-44704/ Different types of habitats Habitat: A place where an organism or a group of organisms lives and interacts with its surroundings. Geographical or physical locations provide the necessary resources for an organism’s survival and reproduction. Habitats can vary in size, small microhabitats, such as the space beneath a rock, to large habitats, such as a tropical rainforest. Habitats consist of both biotic (living) and abiotic (non-living) factors By understanding all these things, we can have a complete idea of a species’ habitat and what it needs to survive. Geographical location: Found on a map or specific area Examples Tropical: Rainforest in the amazon (South America) or The Congo (Africa) located on or around the equator Polar: located at the north and south poles 6  Physical locations: includes factors such as the type of soil, availability of water and food, plant and animal communities that inhabit the area. Examples: Mangrove Swamps: Water availability: Brackish water (mix of salt and freshwater) with high salt content. Type of soil: soft mud or silt, which is rich in nutrients but also low in oxygen. Plant Communities: Mangrove trees have specific adaptations that allow them to survive in saline conditions. Caves – Underground ecosystems. Water availability: Dripping water small pools and underground rivers or lakes. Type of soil: Bat guano provides nitrogen and organic material Animal communities: specialised organisms such as bats, insects, and bacteria that have adapted to dark and nutrient-poor conditions. No plant communities where caves have no light Type of Ecosystem: may occur in many different locations Examples: Marine (Aquatic - Salt water): Coral reefs, open ocean. Freshwater (Aquatic): Ponds, lakes, rivers Terrestrial (land): Grasslands, boreal forests, deserts, tropical rainforests, mountains. Adaptations of organisms to the abiotic environment B4.1.2—Adaptations of organisms to the abiotic environment of their habitat. Include a grass species adapted to sand dunes and a tree species adapted to mangrove swamps. Adaptations of animals to abiotic environmental factors European Red Fox (Vulpes vulpes) Polar Bear (Ursus maritimus) Abiotic Factors: Seasonal (temperature Abiotic Factors: Cold temperatures and and food availability) ice-covered landscapes in the Arctic. Adaptations: 7  Adaptations: Adaptations: Seasonal Fur Changes: grows a thicker Thick Fur and Blubber: Polar bears have coat during the winter months to protect dense fur and a thick layer of blubber that against the cold, sheds coat in the warmer provides insulation against the freezing months to regulate body heat. temperatures. Omnivorous Diet: (including small White Fur for Camouflage: Their white fur mammals, birds, fruits, and insects) allows helps them blend into the snowy environment, it to adapt to the seasonal availability of making it easier to hunt prey, such as seals. food in temperate forests. Large Paws: Their large paws are adapted to Burrowing Behavior: In colder months it walking on ice and swimming, allowing them to digs or finds dens to shelter from harsh efficiently hunt and travel in their environment. weather conditions, conserving body heat during the winter. Adaptations of plants to abiotic environmental factors (These are mentioned in the syllabus, so you need to know these). Marram Grass (Ammophila arenaria) Adaptations of Marram Grass Tolerance to Salt Specialised leaf cells can excrete excess salt, preventing toxic levels from building up inside the plant. The roots are adapted to selectively absorb essential nutrients while minimising the uptake of harmful salts from the soil. Can maintain water uptake in saline conditions by adjusting the concentration of solutes within its cells, allowing it to continue absorbing water despite the high salt content in the soil. Drought: Deep root system that allows it to access water and nutrients even during long periods of drought. Roots: 8  Strong and deep root system which allows them to anchor themselves firmly in the sand to resist erosion from wind and waves. Leaf Leaves are rolled inwards, reducing the surface area exposed to the air, which helps minimise water loss through transpiration. Stomata are located on the inner side of the rolled leaf, further reducing water loss. Specialised hairs prevent water loss by trapping water vapour. Sand Binding and Rhizomes: Marram grass has rhizomes (underground stems) that spread horizontally, allowing the plant to bind sand and stabilise sand dunes. The rhizomes also allow the grass to colonise new areas, promoting dune formation and stability. Mangrove swamp trees. Red Mangrove (Rhizophora mangle) and Black Mangrove (Avicennia germinans) Tolerance to Salt: Mangrove trees tolerate high salinity by using salt-excluding roots or salt-excreting leaves to prevent excess salt from accumulating in their tissues. Root adaptations: Prop roots grow out from the trunk and branches, anchoring the tree in loose soil and creating a structural framework that helps withstand tidal flows and waves. Leaf Adaptations: 9  thick, waxy cuticles to reduce water loss through evaporation. They may also excrete excess salt through specialised glands and can adjust their orientation to minimise water loss due to direct sunlight. Flood Tolerance: Specialised aerial roots (e.g., pneumatophores) that allow them to take in oxygen from the air, even when their roots are submerged in waterlogged or anoxic (oxygen-poor) soils during high tides. Propagation: Seeds begin to germinate while still attached to the parent tree. Once mature, the seeds drop into the water and float until they find suitable soil to take root, allowing them to colonise new areas. Abiotic Factors & Species Distribution B4.1.3—Abiotic variables affecting species distribution. Include examples of abiotic variables for both plants and animals. Should understand that the adaptations of a species give it a range of tolerance. The abiotic, or non-living, factors in the environment can influence the distribution of species Abiotic factors affect living organisms in a variety of ways Examples and effects of abiotic variables for plants and animals (SaveMyExams) Abiotic factor Effect of factor on living organisms Light intensity Light is required by plants for photosynthesis Temperature affects the rate of enzyme-controlled Temperature reactions Water availability Water is required by all living organisms for survival Different plant species require different pH levels and Soil pH and mineral content nutrient concentrations High wind speeds can increase water loss by Wind speed evaporation from the leaves of plants 10  Carbon dioxide is needed by plants for Carbon dioxide concentration photosynthesis Oxygen is needed by all organisms that carry out Oxygen concentration aerobic respiration Each species has adaptations that allow it to tolerate a specific range of these abiotic conditions. This defines the environments they can thrive in. Adaptations of plants to abiotic factors. https://app.kognity.com/study/app/ibdp-biology-slhl-2025-pc/sid-422-cid-242422/book/limitati ons-of-adaptations-and-range-of-tolerance-id-44705/ Abiotic factor Condition Examples of adaptations Light Insufficient light Ferns and shade-tolerant trees grow larger, thinner leaves and increase chlorophyll content to maximise light absorption. Light Too much light Succulents and cacti have thick, waxy skin that helps them retain water and reflect sunlight. Temperature Extreme high Tomato plants have developed heat shock proteins to temperatures protect against high temperatures. Water Inadequate During drought, rice plants can reduce water loss by water supply closing their stomata. Soil Poor soil quality Legumes have developed symbiotic relationships with nitrogen-fixing bacteria to obtain nitrogen from the air. Adaptations of animals to abiotic factors. Abiotic factor Condition Examples of adaptations Temperature Extreme Polar bears and penguins have thick layers of fur or blubber temperatures to insulate them from extreme cold. 11  Water Fluctuations in Camels and kangaroo rats store water in their bodies to water levels survive in arid environments. Light intensity Changes in light Bats and owls are active at night to avoid predators and take advantage of prey that are active at night. Food Changes in food Herbivores have adapted to have specialised teeth or supply digestive systems to extract nutrients from tough plant material. Climate Climate patterns Bats and ground squirrels hibernate during the winter months to conserve energy and survive in colder temperatures. Ranges of tolerance as a limiting factor in species distribution B4.1.4—Abiotic variables affecting species distribution. Include examples of abiotic variables for both plants and animals. Should understand that the adaptations of a species give it a range of tolerance. Should collect this data themselves from a natural or semi-natural habitat. Semi-natural habitats have been influenced by humans but are dominated by wild rather than cultivated species. Sensors could be used to measure abiotic variables such as temperature, light intensity and soil pH. Abiotic factors limit species distribution, with each species having a range of tolerance for environmental conditions. Within this range, species can survive, but they will not be found where conditions exceed their tolerance. Species have a range of tolerance for all abiotic factors, and these factors interact to determine where species can live. Examples of ranges of tolerance and species distribution The cricket population will be largest when they live within the optimum range for the abiotic factor in question, e.g. water availability. Limiting Factor: If there is not enough water (below the critical minimum) or too much water (above the critical maximum) then the crickets will not survive and the population size will be zero 12  Saguaro Cactus (Carnegiea gigantea) inhabit hot, arid desert environments. Optimal temperature: between 15–45°C Limiting Factor: The cactus cannot survive in areas with freezing temperatures (below 0°C) for extended periods. This limits its distribution to desert regions where winters are mild, and frost is rare. Brown Trout (Salmo trutta) require cold, well-oxygenated water. Optimal temperature: between 10–20°C Limiting Factor: In warmer waters, oxygen levels decrease, making it difficult for trout to survive. This limits their distribution to cool rivers and streams, particularly in higher altitudes or temperate climates. Species adapted to extreme environments often have a wider range of tolerance. These species excel where competition is low but may struggle in more moderate environments due to competition from others. Barnacles? 13 B4.1.4—Collecting data from a natural or semi-natural habitat. Semi-natural habitats have been influenced by humans but are dominated by wild rather than cultivated species. Sensors could be used to measure abiotic variables such as temperature, light intensity and soil pH. Kognity Reading https://app.kognity.com/study/app/ibdp-biology-slhl-2025-pc/sid-422-cid-242422/book/limitati ons-of-adaptations-and-range-of-tolerance-id-44705/ Investigating the Effect of Limiting Abiotic Factors on Species Distribution: A Transect Method (Thank you SaveMyExams) Objective: To investigate how a limiting abiotic factor (e.g., soil water availability) affects species distribution using transect sampling. Materials: Tape measure Quadrats (for belt transects) Sampling containers (if needed) Soil moisture metre (or other equipment specific to the abiotic factor) Field notebook and pen Method: 1. Setup of Transect: ○ Lay out a tape measure along the environmental gradient of interest (e.g., from high to low soil water availability or from the water’s edge to inland on a rocky shore). ○ Ensure the transect covers the full range of the abiotic factor being investigated. 2. Sampling Along the Transect: ○ Continuous Line Transect: Record every species that touches the tape measure along the entire length of the transect. ○ Interrupted Line Transect: Record species touching the tape measure at regular intervals (e.g., every 1 metre). ○ Continuous Belt Transect: Place quadrats end-to-end along the tape measure and record the abundance of species within each quadrat. ○ Interrupted Belt Transect: Place quadrats at regular intervals (e.g., every 1 metre) along the tape and record species abundance. 3. Sampling Considerations: ○ Sample Size: Ensure enough samples are taken to represent the whole habitat and allow for meaningful analysis. ○ Data Collection: Measure the abundance of the target species and record the value of the abiotic factor (e.g., soil water content) at each sampling point. 4. Data Analysis: ○ Estimate species distribution at different levels of the abiotic factor. ○ Compare how species abundance changes across the environmental gradient. 14 How to Do a Line Transect Survey - Nature Matters Academy Sampling saves time compared to counting all individuals in a habitat, but it must be representative of the entire area. Use appropriate sampling methods (e.g., line or belt transects) based on the species and environment being studied. Examples of belt and line transects You will be carrying out these types of transects whilst collecting data for your IA on the Cyprus trip. 15  Abiotic factor Method of measurement Air temperature Thermometer Rain gauge; a funnel collects water in a measuring Rainfall cylinder Hydrometer; an electronic device that measures water Humidity vapour content of air Dissolved oxygen Electronic oxygen sensor A turbidity metre measures light scattered by particles Water turbidity (cloudiness) in the water, or a Secchi disc is lowered into the water until it is no longer visible and the depth recorded Light intensity Electronic light metre Landscape relief (height of land) Contour lines on a map or a GPS Site aspect (direction that site faces) Compass Clinometer; a specialised protractor that allows angle Slope incline to be calculated using trigonometry Soil or water pH Indicator solution Difference in mass between a soil sample and the Soil water content same soil sample after it has been dried 16 Representing Results Using Kite Diagrams Objective: To visually represent the distribution and abundance of organisms along an environmental gradient using a kite diagram. Method: 1. Graph Setup: ○ The x-axis represents the distance along the transect. ○ A central horizontal line is drawn along the transect length, representing the distribution of species. 2. Representing Distribution: ○ Each species is represented by a section of the diagram, positioned along the central line where the species is found. ○ Distribution is shown by the species' position along this horizontal line. 3. Representing Abundance: ○ Abundance is indicated by the width of the "kite" shape extending equally on both sides of the central line. ○ The wider the kite, the greater the abundance of the species at that particular point along the transect. 4. Incorporating Abiotic Factors: ○ Additional sections can be added to the kite diagram to represent changes in abiotic factors (e.g., soil pH, height above sea level) at different points along the transect. 17  Kite diagrams effectively represent both species distribution and abundance in response to environmental gradients. Ensure each species and abiotic factor is clearly labelled on the diagram for accurate interpretation. 18 What are the conditions required for coral reef formation? B4.1.5—Conditions required for coral reef formation. Coral reefs are used here as an example of a marine ecosystem. Factors should include water depth, pH, salinity, clarity and temperature. Coral reefs rely on biochemical processes such as photosynthesis, enzymatic activities, and calcium carbonate deposition that are sensitive to specific environmental conditions like light, temperature, salinity, water clarity, and pH. Deviations from these optimal conditions can disrupt these processes, limiting the distribution and survival of coral reefs. Condition Why it’s important for coral reef formation Coral reefs grow in shallow waters, between 2 and 45 metres, where Water depth sunlight can penetrate and support the growth of photosynthetic algae called zooxanthellae. Reef-building corals have an optimal temperature range, with Water temperature: enzyme activity and other metabolic processes functioning efficiently between 23°C and 29°C. Coral reefs require a specific salinity range to maintain osmotic Salinity: balance and support biochemical processes. The optimal salinity range of 30–37 ppt (parts per thousand) allows corals to regulate the movement of water in and out of their cells efficiently. Corals need clear water so that sunlight can penetrate and reach the Water clarity: zooxanthellae for photosynthesis. This mutualistic relationship provides corals with up to 90% of their energy requirements from the sugars produced by the zooxanthellae. Coral reefs thrive in water with a pH between 8.0 and 8.4, which is pH: slightly alkaline. Corals need slightly alkaline water to form their calcium carbonate skeletons. 19 Terrestrial biome distribution is determined by rainfall (precipitation) and temperature patterns B4.1.6—Abiotic factors as the determinants of terrestrial biome distribution Should understand that, for any given temperature and rainfall pattern, one natural ecosystem type is likely to develop. Illustrate this using a graph showing the distribution of biomes with these two climatic variables on the horizontal and vertical axes. Kognity Link: https://app.kognity.com/study/app/ibdp-biology-slhl-2025-pc/sid-422-cid-242422/book/determ inants-of-biome-distribution-id-44396/ Definition of Biomes A biome is a large community of plants and animals adapted to a specific geographical region's climate and environmental conditions. Biomes are characterised by dominant vegetation, animals, and climate patterns in a given area. Major Terrestrial Biomes Six major terrestrial biomes include: ○ Tropical Rainforest ○ Temperate Forest ○ Taiga ○ Grassland ○ Tundra ○ Hot Desert Key Abiotic Factors Determining Biomes Temperature and rainfall interact to create a unique climate that determines the types of plants and animals that can thrive. For a given combination of temperature and rainfall, one dominant biome is likely to form in that area. 20 Impact of Temperature and Rainfall on Biome Formation Temperature affects biological processes like photosynthesis, growth, and metabolism. Example: Hot, humid regions Dominant Biome: typically tropical rainforests. Rainfall determines water availability, essential for plant and animal survival. Example: Hot, arid (very low precipitation) regions Dominant Biome: typically hot deserts Temperature vs Rainfall graph Biome Distribution Across Different Regions The same biome can occur in geographically different areas if they have similar climates. A temperature vs. rainfall graph illustrates the distribution of biomes based on climate conditions. Example: High temperatures and precipitation support tropical rainforests. low temperatures and precipitation support tundra. 21 Task: Using the diagram of a Temperature vs Rainfall graph and the information from the notes provided answer the following short answer questions. (Mark scheme at the back of this booklet). Questions: 1. Explain how temperature and rainfall interact to determine the type of biome present in a region. 3 marks 2. According to the graph, identify which biome would form in a region with low rainfall and high temperatures. Provide a brief explanation. 2 marks 3. Describe how a tropical rainforest biome differs from a tundra biome in terms of temperature and rainfall requirements, as represented in the graph. 2 marks 4. Using the graph, predict the biome that would form in a region with moderate temperatures and rainfall. Justify your answer with reference to the graph. 2 marks 22 Biomes vs Ecosystems B4.1.7—Biomes as groups of ecosystems with similar communities due to similar abiotic conditions and convergent evolution. Should be familiar with the climate conditions that characterise the tropical forest, temperate forest, taiga, grassland, tundra and hot desert biomes. Biome vs Ecosystem: Biomes: Large areas defined by similar abiotic conditions such as climate, soil, and water, resulting in similar communities of plants and animals. These conditions shape the types of plants and animals that can live there. Biomes are also influenced by broad factors like latitude. Example: Tropical rainforests are found near the equator, while tundra biomes are located closer to the poles. Even though different rainforest biomes have different species, these species all share the same characteristics or traits. This is an example of Convergent Evolution: The process by which different species with different evolutionary histories evolve similar traits due to similar environmental pressures. Example: Different species of desert plants from different parts of the world, such as cacti have evolved similar adaptations to conserve water. Tropical Rainforest Biome Forest Ecosystem in Taiga Ecosystem: A smaller, specific area within a biome that includes interactions between organisms and their environment. Examples on interactions: Altitude: Higher altitudes can result in cooler temperatures, affecting ecosystems. Topography: The physical features of the land, such as mountains or valleys, can influence water flow, soil type, and vegetation patterns. 23  Human Activities: Agriculture, deforestation, and urbanisation can significantly alter ecosystems. What are the adaptations to life in hot deserts and tropical rainforests? B4.1.8—Adaptations to life in hot deserts and tropical rainforest. Include examples of adaptations in named species of plants and animals. Examples of adaptations to life in hot deserts Barrel Cactus (Ferocactus wislizeni) Water Storage: has a thick, fleshy stem that stores water. Spines: that reduce water loss and provide shade to the cactus body, protecting it from the intense desert sun. Shallow, Extensive Root System: Its shallow roots quickly absorb water from rainfall, spreading out widely to collect moisture from the desert soil. Joshua Tree (Yucca brevifolia) Deep Roots: allow the tree to access underground water in the arid desert. Thick, Waxy Leaves: have a thick cuticle to reduce water loss through transpiration. Fennec Fox (Vulpes zerda) Large Ears: help dissipate heat and keep the fox cool. Nocturnal Lifestyle: active at night to avoid the daytime heat. Light Fur: reflects sunlight and provides camouflage in the desert. 24  Dromedary Camel (Camelus dromedarius) Water Conservation: can go long periods without drinking water. Can drink large quantities (40l) in one go. They store fat in their humps: which can be metabolised to produce water when needed. Thermal Regulation: have a thick coat that insulates them from the heat during the day and conserves body heat at night when temperatures drop. Nasal Passages: are adapted to retain water vapour, reducing water loss during respiration Examples of adaptations to life in hot tropical rainforests Epiphytes (e.g., Orchids) Growing on Other Plants: Epiphytes grow on the branches of largert, higher rees to access sunlight in the dense forest canopy. Water Absorption from Air: They absorb moisture and nutrients from the humid air and rain, using specialised structures like aerial roots. Bengal Bamboo (Bambusa tulda) Rapid Growth: Bamboo grows quickly to compete for sunlight in the crowded rainforest. Water Efficiency: Its structure allows for effective water use in the humid and sometimes flooded conditions of the rainforest. 25 Sloth (Bradypus variegatus) Slow Metabolism: allowing them to conserve energy while moving slowly through the trees. Camouflage: Their fur hosts algae, which gives them a greenish tint, blending with the surrounding forest and protecting them from predators. Poison Dart Frog (Dendrobatidae) Bright Colours: have bright, warning colours to signal their toxicity to predators. Moist Skin: Their skin absorbs water and oxygen directly, making them highly adapted to the humid environment of the rainforest. 26 Mark Scheme: Temperature vs Rainfall graph. Short answer questions. 1. Explain how temperature and rainfall interact to determine the type of biome present in a region. 3 marks Temperature and rainfall are the primary abiotic factors that influence biome distribution. (1 mark) High temperatures and high rainfall typically result in biomes like tropical rainforests. (1 mark) Low temperatures and low rainfall are more likely to result in tundra or desert biomes. (1 mark) 2. According to the graph, identify which biome would form in a region with low rainfall and high temperatures. Provide a brief explanation. 2 marks The biome is a desert. (1 mark) Deserts form in areas where rainfall is very low and temperatures are high, as shown on the graph. (1 mark) 3. Describe how a tropical rainforest biome differs from a tundra biome in terms of temperature and rainfall requirements, as represented in the graph. 2 marks Tropical rainforests are found in areas with high temperatures and high rainfall. (1 mark) Tundra biomes occur in areas with low temperatures and low rainfall. (1 mark) 4. Using the graph, predict the biome that would form in a region with moderate temperatures and rainfall. Justify your answer with reference to the graph. 2 marks The biome could be temperate forest or grassland. (1 mark) These biomes typically form in areas with moderate temperature and rainfall, as represented in the middle portion of the graph. (1 mark) 27