B4.1 Adaptations to the environment

What is an oxygen dissociation curve?

An oxygen dissociation curve shows the percentage of oxygen saturation of hemoglobin at different oxygen concentrations.

What is the normal atmospheric pressure?

The normal atmospheric pressure is 101.3 kPa.

What is the partial pressure of oxygen in normal atmospheric conditions?

The partial pressure of oxygen in normal atmospheric conditions is 21.2 kPa.

Why do oxygen dissociation curves usually only cover a range from 0 kPa to 15 kPa?

Oxygen dissociation curves usually only cover a range from 0 kPa to 15 kPa because the oxygen concentration inside the alveoli is lower.

What does the sigmoid form of the oxygen dissociation curve indicate?

The sigmoid form of the oxygen dissociation curve is due to cooperative binding.

What are biotic factors in an environment?

Biotic factors are the living organisms in an environment.

What are abiotic factors in an environment?

Abiotic factors are the non-living materials in an environment, such as air, water, and rock.

In which types of ecosystems do biotic factors dominate?

Biotic factors dominate in ecosystems with dense communities of organisms, such as tropical rainforests.

In which types of ecosystems do abiotic factors dominate?

Abiotic factors dominate in extreme habitats with low population densities, such as deserts or taigas.

How are plants adapted to grow in extreme habitats like sand dunes and mangrove swamps?

Plants in extreme habitats are adapted to challenges like water conservation, salt tolerance, and sand accumulation.

What are sand dunes?

Sand dunes are mounds of sand formed by wind-blown sand in deserts and at the top of beaches.

What are the challenges for plants growing on beach dunes?

The challenges include water conservation, high salt concentrations, and limited organic matter.

Why does sand retain little water after rainfall?

Sand retains little water after rainfall because it has low water retention capacity and poor organic matter content.

How do Lyme grass plants adapt to sand dune environments?

Lyme grass adapts with a thick waxy cuticle, stomata in indentations, leaf rolling during droughts, tough sclerenchyma, and deep rhizomes for water absorption.

What is the role of fructans in Lyme grass roots and leaves?

Fructans accumulate in roots and leaves to increase osmotic potential, aiding water uptake.

What environmental challenges do mangrove swamps face?

Mangrove swamps are flooded with seawater, have waterlogged, anaerobic soils, and high salt concentrations.

How do mangrove trees adapt to high salt concentrations?

Mangrove trees secrete excess salt through salt glands, have roots coated in suberin, and accumulate mannitol to increase osmotic potential.

What is the function of pneumatophores in mangrove trees?

Pneumatophores are vertical root branches that absorb oxygen for use in roots in oxygen-poor soils.

What is the function of stilt roots in mangrove trees?

Stilt roots help buttress the tree in soft mud and provide stability.

How do mangrove trees reproduce in their environment?

Mangrove trees produce large buoyant seeds that can be carried by the ocean to distant shores.

What abiotic factors affect the distribution of plant species?

Abiotic factors include temperature, water availability, light intensity, soil pH, salinity, and the availability of mineral nutrients.

What is the range of tolerance of plant species?

The range of tolerance refers to the specific environmental conditions in which a plant can survive and grow.

Why can't tropical plant species survive in northern regions?

Tropical plant species are not adapted to frost and cannot survive cold temperatures in northern regions.

How do northern plant species survive in cold environments?

Northern plants have chemicals that act like antifreeze to prevent frost damage.

How do northern plants fare in tropical environments?

Northern plants struggle in tropical environments due to excessive transpiration and inefficient photosynthesis at high temperatures.

What are some adaptations of animals to hot climates?

Animals in hot climates may have adaptations like large ears for heat dissipation, reduced water loss, and nocturnal behaviors.

How do elephants dissipate heat in hot climates?

Elephants use large ears with dense blood vessels to radiate heat and cool their bodies.

How do polar bears minimize heat loss in cold environments?

Polar bears have relatively small ears to minimize heat loss in Arctic habitats.

How do desert rats minimize water loss?

Desert rats have longer loops of Henle in their kidneys to reduce water loss.

How are aquatic animals adapted to their environment?

Aquatic animals have specialized adaptations for respiration, buoyancy, and osmotic regulation in aquatic habitats.

What is an example of a species with a specific requirement for its habitat?

Salmon require fast-flowing freshwater streams for spawning, with specific pH and gravel substrate conditions.

How are ranges of tolerance for abiotic factors investigated?

Ranges of tolerance can be studied experimentally or through correlations between species distribution and abiotic variables.

What factors limit the distribution of coral reefs?

Coral reefs are limited by factors like depth, pH, salinity, clarity, and temperature.

What temperature range is necessary for coral reefs to thrive?

Coral reefs require temperatures between 23–29°C to remain healthy.

What salinity range is required for coral reefs?

Coral reefs need salinity levels between 32 and 42 parts per thousand to avoid osmotic problems.

What abiotic factors determine biome distribution?

Temperature and rainfall are the principal factors that determine biome distribution.

What is the relationship between biomes and ecosystems?

Biomes are large groups of ecosystems that have similar abiotic conditions and are characterized by similar plant and animal adaptations.

What is convergent evolution?

Convergent evolution is the process by which distantly related species evolve similar adaptations in response to similar environmental challenges.

What adaptations do desert plants like cacti and euphorbias have?

Both cacti and euphorbias have adaptations for water conservation, such as storing water and reducing transpiration.

What are the main characteristics of hot deserts?

Hot deserts have high daytime temperatures, cold nights, low rainfall, and limited soil development.

How is the saguaro cactus adapted to desert life?

The saguaro cactus has wide-spreading roots, fat stems for water storage, pleated stems for shrinking and swelling, and a waxy cuticle to reduce transpiration.

How does the saguaro cactus conserve water?

The saguaro cactus conserves water through CAM metabolism, which opens stomata at night and closes them during the day to reduce water loss.

How is the fennec fox adapted to hot desert life?

The fennec fox is nocturnal, builds underground dens, has thick fur, large ears for heat dissipation, and a pale coat to reflect sunlight.

How do the fennec fox's ears help regulate temperature?

The large ears of the fennec fox radiate heat, helping it maintain a cool body temperature in hot environments.

What are the characteristics of tropical rainforests?

Tropical rainforests have high temperatures, high precipitation, and high light intensity.

How is the meranti tree adapted to the rainforest?

The meranti tree can grow over 100 m tall, has a dense trunk for support, smooth bark to shed rain, and evergreen leaves for year-round photosynthesis.

What adaptations does the spider monkey have for life in the rainforest?

The spider monkey has long arms and legs for climbing, a prehensile tail, and hook-like hands for grasping branches.

Why do spider monkeys sleep at night?

Spider monkeys sleep at night because they are diurnal and need rest to be active during the day when their vision is best.

How do tropical rainforest plants shed rainwater?

Tropical rainforest plants like the meranti tree have broad, pointed leaves that shed rainwater rapidly.

How do spider monkeys communicate in the dense rainforest canopy?

Spider monkeys have a highly developed larynx that allows a wide range of sounds for communication.

Why are tropical rainforest plants adapted to grow tall?

Tall growth helps rainforest plants like the meranti tree to compete for light in the dense canopy.

How do tropical rainforest plants ensure reproduction?

Tropical rainforest plants like the meranti produce large quantities of seeds at intervals to avoid predation.

What is the role of buttressed trunks in rainforest trees?

Buttressed trunks provide support in shallow, nutrient-poor soils that are common in tropical rainforests.

How do the large seeds of mangrove trees benefit their reproduction?

The buoyant seeds of mangrove trees can be carried by the ocean to new locations for colonization.

What abiotic factors are important for coral reefs?

Depth, pH, temperature, salinity, and clarity of the water are essential for coral reef health.

Why is temperature important for coral reefs?

Temperature affects the health of corals and their mutualistic relationship with zooxanthellae, which need light for photosynthesis.

How does the clarity of water affect coral reefs?

Clear water is necessary for light penetration, which is crucial for the photosynthesis of zooxanthellae in corals.

What adaptations do animals in desert ecosystems have for conserving water?

Animals in deserts may have adaptations such as efficient kidneys, nocturnal behavior, and water storage in tissues.

How does the yellow meranti tree maximize light capture?

The yellow meranti grows very tall, avoiding competition for light in the dense rainforest canopy.

What is the relationship between abiotic factors and the distribution of plant species?

The distribution of plant species is strongly influenced by abiotic factors such as temperature, water availability, and soil conditions.

How do temperature and precipitation affect the formation of biomes?

Temperature and precipitation are key determinants of the types of ecosystems and biomes that develop in a given area.

What is the primary cause of biodiversity in coral reefs?

Coral reefs are biodiverse because they provide a wide range of habitats and are highly productive ecosystems.

How do mangrove trees manage the anaerobic soil conditions in swamps?

Mangrove trees have specialized root structures like pneumatophores that allow them to absorb oxygen from the air.

What is the role of salt glands in mangrove trees?

Salt glands help mangrove trees excrete excess salt, allowing them to survive in saline environments.

How do desert plants like cacti store water?

Cacti have specialized tissues, such as fat stems, to store water from infrequent rains in desert environments.

What adaptations help plants in tropical rainforests thrive in high humidity?

Plants in tropical rainforests often have smooth trunks and leaves that shed water quickly to avoid excessive moisture buildup

How are species distribution maps useful in studying ecosystems?

Species distribution maps help researchers understand how environmental factors, including abiotic factors, influence where species live.

What is the significance of the pleated stem in the saguaro cactus?

The pleated stem of the saguaro cactus allows it to expand and store water after rainfall, and shrink during droughts to conserve water.

How do mangrove trees support their structure in soft, waterlogged soil?

Mangrove trees use stilt roots to anchor themselves in soft, unstable mud, providing physical support.

Why do spider monkeys have prehensile tails?

Prehensile tails help spider monkeys grasp branches and aid their mobility in the rainforest canopy.

What is an example of convergent evolution in plants? Cacti in the Americas and euphorbias in Africa both have similar adaptations for water conservation, despite not being closely related.

Why are desert animals often nocturnal?

Desert animals are nocturnal to avoid the extreme heat during the day, reducing water loss and exposure to heat.

What is the relationship between light intensity and tropical rainforest plants?

Tropical rainforest plants are adapted to high light intensity, but many grow tall to access the sunlight above the canopy.

How do large ears help desert animals like the fennec fox? Large ears help desert animals like the fennec fox dissipate heat and regulate their body temperature in hot environments.

Why are tropical rainforest plants evergreen?

Evergreen leaves allow tropical rainforest plants to photosynthesize year-round, taking advantage of consistent, optimal conditions

How does the size of an animal's kidneys help in water conservation?

Animals in dry environments, such as desert rats, have specialized kidneys that allow them to conserve water efficiently.

How does a waxy cuticle reduce transpiration in desert plants?

A waxy cuticle on plant surfaces reduces water loss by preventing excessive evaporation.

How do mangrove trees handle high salt concentrations?

Mangrove trees have salt glands that excrete excess salt, and they can accumulate mannitol in their cells to maintain water uptake.

How do coral reefs support biodiversity?

Coral reefs provide habitats for a wide variety of species, fostering high biodiversity in the ecosystem.

Why is the large size of the meranti tree an adaptation for the rainforest?

The meranti tree's large size allows it to grow above the dense canopy and compete effectively for light in the rainforest.