IB Biology: Ecology, Adaptations, Niches, Populations, and Energy Transfers

500 practice flashcards covering topic units B4.1, B4.2, C4.1, and C4.2 based strictly on the provided lecture notes.

What is the definition of a habitat?

A habitat is a geographical/physical location that provides necessary resources for an organism's reproduction and survival, consisting of abiotic and biotic factors where an organism or group of organisms lives and interacts with surroundings.

What are the two broad categories into which habitats can be classified?

Terrestrial habitats and aquatic habitats.

What are terrestrial habitats defined as?

Land-based environments.

What are aquatic habitats defined as?

Water-based environments.

What three main aspects are used to describe a habitat?

1) Geographical location (map or specific area), 2) Physical location (types of soil, availability of water/food, plants and animals around), and 3) Ecosystem (big picture of all biotic and abiotic factors and their relationships in a specific area).

What two primary divisions are shown branching from 'Habitat' in this classification diagram?

Terrestrial habitat and Aquatic habitat.

According to the habitat classification diagram, what are the three examples listed under Terrestrial habitat?

Desert, Mountain, and Grassland.

According to the habitat classification diagram, what are the two examples listed under Aquatic habitat?

Ocean and Pond.

What is the biological definition of an adaptation?

An adaptation is the genetic change that increases an organism’s ability to survive in a particular environment.

What mechanism drives adaptations in organisms?

Natural selection.

Do adaptations occur intentionally or randomly?

They happen randomly.

What are the three environmental issues faced by plants in sand dunes?

Lack of water, high salt concentration, and sand accumulation.

What adaptation does Lyme grass have to reduce transpiration in sand dunes?

A thick waxy cuticle.

How do indented stomata benefit Lyme grass in windy sand dune conditions?

Humid air can remain inside the indentations even in windy conditions, reducing water loss.

Why do Lyme grass leaves roll up during droughts?

To create a humid chamber and to reduce surface area.

What is the function of tough sclerenchyma in Lyme grass?

To prevent wilting during droughts.

What are rhizomes in Lyme grass, and how do they adapt the plant to sand accumulation and water retrieval?

Rhizomes are underground stems that grow up as sand accumulates and extend deep to obtain water.

Why does Lyme grass accumulate fructans (carbohydrates) in its tissues?

To increase osmotic potential.

According to the table shown, what adaptation of Lyme grass addresses the issue of sand accumulation?

Rhizomes (underground stems) that grow up as sand accumulates.

What are five environmental issues faced by organisms in mangrove forests?

Sheltered conditions, mud accumulates, swamps flooded with seawater, high salt concentrations, and waterlogged anaerobic soils.

What adaptation do mangrove trees have in their leaves to deal with high salt concentrations?

Salt glands in leaves to secrete excess salt.

Why is the root epidermis of mangrove trees coated in suberin?

To reduce permeability to salt.

What are cable roots in mangrove trees and where do they grow?

Cable roots are horizontal roots growing close to the soil surface where there is the most oxygen.

What are pneumatophores in mangrove trees?

Vertical roots that grow up into the air to absorb oxygen.

What type of roots grow downward in an arch in mangrove trees to provide support?

Stilt roots.

What feature of mangrove seeds aids in their dispersal in flooded swamps?

They are large buoyant seeds.

Besides salt glands and suberin coatings, how do mangrove trees increase osmotic potential to absorb water from seawater?

Accumulation of ions to increase osmotic potential.

According to the table shown, what mangrove adaptation specifically addresses waterlogged anaerobic soils by growing vertical roots into the air?

Pneumatophores (vertical) roots.

What four main environmental issues characterize hot deserts?

Very high daytime temperatures, cold nights, low rainfall, and limited soil development.

How wide is the root system of a Saguaro cactus?

$$30\,m$$

What structural feature allows Saguaro cactus stems to store water?

Fat stems with storage tissue for water.

How do Saguaro cactus stems respond to fluctuating water levels?

They have stems that allow shrinkage.

Why are the stems of the Saguaro cactus oriented vertically?

To reduce light intake at midday and maximize it at colder times.

What is the advantage of leaves being reduced to spines in the Saguaro cactus?

To lower surface area and protect against predation.

What metabolic adaptation does the Saguaro cactus use to reduce transpiration?

CAM metabolism, where stomata open at night to reduce transpiration.

What behavioral adaptation allows the Fennec fox to avoid high daytime temperatures?

It is nocturnal and builds an underground den to stay cool during the day.

How do long thick hairs benefit the Fennec fox?

They provide insulation against cold desert nights.

Why does the Fennec fox have hair on its feet?

To protect its feet when walking on hot sand.

What is the advantage of the Fennec fox's pale coat?

To reflect sunlight.

What role do the large ears of the Fennec fox play in thermal regulation?

They radiate heat.

What respiratory adaptation causes heat loss in the Fennec fox?

A variable ventilation rate.

According to the table shown, what adaptation of the Saguaro cactus specifically addresses low rainfall and limited soil development by capturing surface moisture?

Wide-spreading root system ($30\,m$).

What three environmental issues are listed for tropical rainforests?

High temperatures, high precipitation, and high light intensity.

How tall can a Meranti tree grow to obtain light in tropical rainforests?

Over $100\,m$

What structural adaptation helps the Meranti tree withstand wind?

A trunk of hard dense wood.

Why is the trunk of a Meranti tree buttressed at the base?

For support because the soil is shallow.

How do the smooth trunk and broad oval leaves of the Meranti tree adapt it to high precipitation?

They allow the tree to shed rainwater.

How are photosynthesis enzymes adapted in Meranti trees?

They are adapted for high temperatures.

What reproductive adaptation does the Meranti tree display?

Producing seeds in large quantities.

What anatomical adaptations allow the spider monkey to climb and swing in the forest canopy?

Long arms/legs for climbing and flexible shoulders to swing.

How are the hands and feet of the spider monkey adapted for arboreal life?

Hook-like hands to grasp branches and pick fruit, and feet that act like extra hands.

What feature of the spider monkey's tail helps it navigate trees?

It is a long tail that can grip onto branches.

What vocal adaptation does the spider monkey possess?

A highly developed larynx to be able to make a wide range of sounds.

Why does the spider monkey sleep at night?

So branches can be seen.

According to the table shown, why does the Meranti tree require a buttressed trunk at its base?

For support because soil is shallow.

What is defined as the range of environmental conditions within which an organism can survive and function optimally?

Range of tolerance.

What is species distribution?

The geographic location and range of occurrence of a particular species.

What primary factor influences species distribution?

The range of tolerance.

What are five key abiotic factors that affect plant and animal distribution?

Light intensity, temperature, water availability, soil nutrients, and atmospheric gases.

What environmental factors can alter an organism's range of tolerance?

Climate change, pollution, and habitat destruction.

What is the transect line method?

A sampling technique used in ecology to gather data on the distribution and abundance of plants and animals in a particular area by establishing a straight line across a habitat and taking measurements at regular intervals.

What are the steps involved in executing a transect line sampling procedure?

1) Set out a tape measure/rope in a straight line across the habitat, and 2) Take measurements or samples at regular intervals along the line.

What five variables can be measured along a transect line?

Plant species richness, plant height, leaf area index, soil moisture, and animal abundance.

What is a belt transect?

A sampling technique where a long, narrow belt is placed over the area of interest to count the number of individuals within the belt, used to study organism distribution and abundance.

What is an observational transect?

A sampling technique used in environmental monitoring to observe and record data along a designated linear path/transect.

What is line intercept sampling?

A method used to measure the abundance and distribution of plants in a habitat by recording the points where a line/tape intersects with plant stems or foliage.

What are four key advantages of using sensors and data loggers in ecological studies?

1) They can provide continuous precise measurements, 2) They can operate in hazardous or remote environments, 3) They can provide real-time data that can be analysed and acted upon quickly, and 4) They can take multiple readings fast.

What are corals?

Corals are animals that grow in colonies.

What are coral reefs constructed of?

Calcified skeletons of coral animals.

What depth of water is required for coral reef formation, and why?

Between $2$ and $45\,m$, so sunlight can penetrate and support algae growth.

What pH range is required for coral reef formation?

Between $8$ and $8.4$

What salinity range is required for coral reef formation, and why?

Between $32$ and $34\text{ parts per thousand (ppt)}$, to avoid osmotic problems.

Why is water clarity important for coral reefs?

For light penetration to support photosynthetic algae (zooxanthellae).

What type of photosynthetic algae lives in a symbiotic relationship with coral reefs?

Zooxanthellae.

How do corals and zooxanthellae benefit each other?

Corals protect the algae, and the algae produce oxygen and nutrients for the coral.

What temperature range is required for coral reef formation?

Between $23-29\,^\circ\text{C}$

What are the five essential abiotic conditions required for coral reef formation?

Water depth ($2-45\,m$), pH ($8-8.4$), salinity ($32-34\text{ ppt}$), water clarity, and temperature ($23-29\,^\circ\text{C}$).

Which two abiotic factors primarily determine the distribution of terrestrial biomes?

Rainfall (y-axis) and Temperature (x-axis).

How does rainfall influence biomes?

It determines the availability of water content.

How does temperature influence biomes?

It affects the rate of biological processes.

Why do similar biome conditions result in similar animals and plants in different global locations?

Due to convergent evolution.

According to the biome graph shown, which biome exists at an average temperature of $-5\,^\circ\text{C}$ to $0\,^\circ\text{C}$ and very low rainfall pattern below $50\text{ cm}$?

Tundra.

According to the Whittaker biome chart, which biome is characterized by temperatures above $20\,^\circ\text{C}$ and rainfall exceeding $250\text{ cm}$?

Tropical rainforest.

According to the biome graph shown, which biome occupies high temperatures (around $20\,^\circ\text{C}$ to $30\,^\circ\text{C}$) with low rainfall patterns below $100\text{ cm}$?

Subtropical desert.

What is the definition of biomes?

Biomes are groups of ecosystems that share similar abiotic conditions.

What is a specialist species?

A specialist species is a species adapted to grow in narrow habitats, limited food resources, or other specific environmental conditions.

What is a generalist species?

Generalist species are organisms that can survive a broader range of environments.

Which type of species is often most vulnerable when environmental conditions change?

Specialist species.

What is an ecological niche?

Where an animal lives, what it does, its role, and its impacts on the ecosystem.

What is an obligate anaerobe?

Organisms that can only survive in environments that lack oxygen.

What example of an obligate anaerobe is given in the notes?

Bacteria.

What is an obligate aerobe?

Organisms that can only survive in environments that contain oxygen.

What example of an obligate aerobe is provided in the notes?

Humans.

What is a facultative anaerobe?

Organisms that can survive in environments that contain or lack oxygen.

What example of a facultative anaerobe is given in the notes?

E. coli.

According to the mode of respiration table shown, how is E. coli categorized?

Facultative anaerobe.

What is an autotrophic organism?

An organism that can produce its own energy / synthesize organic molecules using an external energy source.

What energy conversion occurs in photosynthesis?

Light energy to chemical energy.

What three groups of organisms are listed under photosynthesis autotrophs?

Plants, Eukaryotic algae, and Cyanobacteria.

What are chemoautotrophs?

Autotrophic organisms that use light energy or oxidation of inorganic compounds to chemical energy to produce their own energy.