Ecology Flashcards
What is ecology?
The study of relationships between living organisms and between organisms and their environment.
Ecologists study various ecosystems, which can vary in size from the biosphere to a single drop of water.
What is an organism?
One living individual.
Organisms can be of any type, including plants, animals, fungi, and microorganisms.
What is a population?
A group of organisms of the same species living in the same area at the same time.
Populations can vary greatly in size and density.
What is a community in ecology?
A group of different populations living and interacting with each other in a particular ecosystem.
Communities can include various species of plants, animals, and microorganisms.
Define a species.
A group of living organisms that can interbreed and produce fertile offspring.
Species are often defined by their genetic similarity and reproductive isolation.
What is a niche?
The role in which a species normally performs or the job of a living organism.
A niche encompasses how a species interacts with its environment, including its habitat and food sources.
Define habitat.
A particular environment in which a species normally lives or the home of a living organism.
Habitats can range from forests to deserts to aquatic environments.
What are producers in an ecosystem?
Organisms that make their own food, also known as autotrophs.
Examples include green plants, algae, and cyanobacteria.
What is photosynthesis?
The process by which plants manufacture sugar (glucose) from carbon dioxide and water using sunlight.
This process is essential for producing organic molecules in ecosystems.
What are consumers?
Organisms that are directly or indirectly dependent on autotrophs for their food, also known as heterotrophs.
Consumers cannot produce their own food and rely on other organisms.
List the types of consumers.
- Herbivores
- Carnivores
- Omnivores
- Detritivores
- Decomposers
Each type of consumer has a different source of food.
What are herbivores?
Consumers that feed on producers.
Examples include zebra, springbok, mice, aphids, and krill.
What are carnivores?
Consumers that feed on other consumers.
Examples include lions, cheetahs, eagles, ladybirds, and tuna.
What are omnivores?
Consumers that feed on both producers and consumers.
Examples include humans, dogs, ants, and sardines.
What are detritivores?
Consumers that feed on dead plants or animals.
Examples include woodlice and earthworms.
What are decomposers?
Heterotroph organisms that break down dead organisms and organic wastes into inorganic substances.
Examples include bacteria and fungi, also known as saprotrophs.
True or False: A tree only provides food for consumers.
False.
A tree also provides habitat for many organisms.
Fill in the blank: The living components of an ecosystem are called _______.
[biotic components].
These include all the living organisms within the ecosystem.
Fill in the blank: The non-living components of an ecosystem are referred to as _______.
[abiotic components].
These include elements like water, air, soil, and sunlight.
What is the primary purpose of food chains and food webs?
To describe the transfer of energy within an ecosystem
Food chains and webs show who eats whom and how energy and matter move through ecosystems.
What does an arrow in a food chain or food web indicate?
The direction of energy flow
The arrow always points towards the consumers.
What is the sequence of a typical food chain?
Producer → primary consumer → secondary consumer → tertiary consumer → decomposer
This sequence represents a single pathway of energy flow.
Why are food chains generally simpler than actual ecological interactions?
Most organisms consume and are consumed by more than one species
Food webs depict this complexity better than food chains.
What are trophic levels?
The feeding positions in a food chain or web
All food chains and webs have at least two or three trophic levels.
What is the maximum number of trophic levels typically found in ecosystems?
Five
Very large ecosystems, such as oceans, may have more.
How much energy is typically passed from one trophic level to the next?
About 10 percent
The remaining 90 percent is used for metabolic processes or lost as heat.
What explains the rarity of more than four trophic levels in a food chain or web?
The loss of energy at each trophic level
There is usually not enough energy left to support additional levels.
What are ecological pyramids used for?
To demonstrate changes in energy, biomass, or numbers within an ecosystem
They visually represent the distribution of energy or biomass at different trophic levels.
What does a pyramid of energy show?
How much energy is retained in the form of new biomass at each trophic level
This pyramid illustrates energy flow in an ecosystem.
What does a pyramid of biomass represent?
The amount of living or organic matter present in organisms at different trophic levels
It reflects the total biomass at each level.
What does a pyramid of numbers represent?
The number of individual organisms at each trophic level
This pyramid can be inverted or take other shapes due to size variation among organisms.
True or False: Pyramids of energy and biomass are normally upright.
True
Pyramids of numbers can vary in shape.
What is bioaccumulation?
The gradual accumulation of substances, such as pesticides or other chemicals, in an organism.
Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it is lost or eliminated.
What is biomagnification?
The increased concentration of a poison in the tissues of tolerant organisms at successively higher levels in a food chain.
This phenomenon results in organisms at the top of the food chain having higher tissue concentrations of poisons and pollutants.
What are climatic factors in ecosystems?
Factors include light, temperature, water, wind, and air composition.
These factors play a crucial role in shaping the environment and the organisms that inhabit it.
How do strong winds affect ecosystems?
They speed up evaporation, assist in the pollination of plants, and help in the dispersal of seeds.
For instance, in the Western Cape, winds help disperse seeds of proteas that are released after a fire.
True or False: Environmental toxins can cause significant harm to ecosystems even at low levels.
True
Examples include long-term effects of low levels of environmental poisons like mercury.
Fill in the blank: _______ is the process when an organism absorbs a substance faster than it is eliminated.
[Bioaccumulation]
This process leads to the accumulation of harmful substances in the organism over time.
What is the main consequence of biomagnification in food chains?
Organisms at the top of the food chain have a higher concentration of toxins than those at lower levels.
This can lead to health risks for predators, including humans.
Name three climatic factors that influence ecosystems.
- Light
- Temperature
- Water
These factors are essential for the survival and growth of various organisms.
What role does wind play in seed dispersal?
Wind helps in the dispersal of seeds by blowing them further away from the parent plant.
This can increase the chances of germination in new areas.
Fill in the blank: _______ refers to the harmful effects that low levels of environmental poisons can have over time.
[Long-term effects]
Such effects can be observed in ecosystems affected by pollutants like mercury.
What are the main components of air?
78% nitrogen, 21% oxygen, 0.04% carbon dioxide, variable water vapour
The composition of air is crucial for understanding atmospheric science and biochemistry.
What cycle uses oxygen in cellular respiration and returns it through photosynthesis?
Oxygen cycle
This cycle is vital for the survival of aerobic organisms.
What is the role of carbon dioxide in the carbon cycle?
Product of cellular respiration and decayed organic matter
Plants remove carbon dioxide from the atmosphere during photosynthesis.
What is the nitrogen cycle important for?
Synthesis of proteins
All living organisms require nitrogen for protein synthesis.
How does the amount of water vapour in the air vary?
Remains fairly constant on average, varies greatly from place to place
High humidity levels are found in some areas, while others may have dry air.
What weather phenomena are caused by the condensation of water vapour?
Clouds, rain, and snow
Water vapour plays a crucial role in weather patterns.
What is essential for the process of photosynthesis?
Light
Producers like plants rely directly on sunlight for energy.
How do heterotrophs obtain energy?
By consuming plants or other heterotrophs
Heterotrophs depend on autotrophs for energy indirectly.
What process releases energy stored in sugars?
Cellular respiration
This process is critical for all organisms to obtain energy.
What is photoperiodism?
Plant growth affected by the length of the day
Some plants only flower when the day length reaches a certain duration.
What light condition do some plants need for optimal growth?
High levels of light or full sunlight
Other plants may thrive in shady conditions.
Define nocturnal.
Active during the night
Examples include bats and honey badgers.
Define diurnal.
Active during the daytime
Most birds and humans are diurnal.
Define crepuscular.
Active primarily during the twilight period
Examples include housecats and rats.
What is temperature’s effect on evaporation and transpiration?
Temperature affects the rate of evaporation and transpiration
Seasonal changes in weather are influenced by temperature variations.
How does temperature influence seed germination?
Germination of seeds requires warm temperatures
Seasonal variation in vegetation is linked to temperature.
What are the two types of temperature-related adaptations in animals?
Endothermic and Ectothermic
Endothermic animals maintain a constant body temperature, while ectothermic animals depend on environmental temperatures.
What is hibernation?
A winter sleep for the cold season
Hibernation is an adaptation for surviving cold temperatures.
What are annuals in the context of plant adaptations?
Plants that complete their life cycle in one season and survive harsh seasons as seeds
Annuals are adapted to quickly grow and reproduce before unfavorable conditions.
What do deciduous plants do during harsh seasons?
Lose leaves and reduce metabolism to survive
This adaptation helps them conserve energy and water.
What are bulbs, tubers, and rhizomes?
Plants with below-ground parts that survive harsh seasons or fire
These structures store nutrients and provide resilience against environmental stress.
What is the significance of water in living organisms?
Water is essential for all living organisms and is a major component of cells
About 80% of the human body and 90% of the plant body consists of water.
How is water distributed across the Earth?
Water is not evenly distributed; abundant in aquatic ecosystems and least abundant in deserts
This distribution affects ecosystem types and species adaptations.
What are xerophytes?
Plants that live in dry habitats or regions with low annual rainfall
Xerophytes are adapted to resist drought and cope with high temperatures.
What defines mesophytes?
Plants that need an average, regular supply of water
They thrive in moderate environments with consistent moisture.
What are hydrophytes?
Plants that live entirely or partially submerged in water or in very wet soil
These plants need to cope with a water surplus.
Fill in the blank: An extremely rare strategy is found in some plants that can dry out and come back to life when water is available, such as the _______.
resurrection plant
This ability allows certain plants to survive extreme drought conditions.
What are physiographic factors?
Factors relating to the physical geography of the environment that affect ecosystems, including slope, aspect, and altitude.
What does the term ‘aspect’ refer to in ecology?
The direction or side that a particular ecosystem is facing in relation to the sun, wind, or wave action.
How does aspect influence ecosystems in the Southern Hemisphere?
North-facing slopes receive more direct sunlight, making them warmer and drier, while south-facing slopes are cooler and wetter.
In the Southern Hemisphere, which slopes are typically sunnier and warmer?
North-facing slopes.
In the Northern Hemisphere, which slopes are hotter and sunnier?
South-facing slopes.
What is the effect of ecological aspect observed on the slopes of Devils Peak?
Newlands Forest is on the cooler, shadier south to southeast slopes, while scrubby fynbos vegetation is on the hotter, sunnier north-facing slopes.
What is meant by ‘slope’ in an ecological context?
The degree of incline or slope of the ground in an ecosystem.
How does slope affect soil fertility?
Steep slopes typically have less soil, leading to less fertile ecosystems due to greater runoff and soil erosion.
What is the definition of altitude?
The height above (or below) sea level.
What environmental conditions are associated with high altitude ecosystems?
More extreme weather, such as strong winds and snow, along with different temperatures and atmospheric gases.
How do plants and animals at higher altitudes adapt to their environment?
They have adaptations to survive harsher conditions.
Fill in the blank: South-facing slopes in the Southern Hemisphere are typically _______.
cooler and wetter.
True or False: At lower altitudes, the weather is generally more extreme and less sheltered.
False.
What types of vegetation are typically found on south-facing slopes in Cape Town?
Shade plants, such as ferns.
What happens to the amount of soil on steep slopes?
It is typically less, resulting in less fertile ecosystems.
What is one major consequence of greater runoff on steep slopes?
Greater soil erosion.
What are edaphic factors?
Soil factors including soil texture, soil air, soil water, humus content, and soil pH.
Edaphic factors are critical for understanding soil health and its capacity to support plant life.
What role does soil play in supporting plants?
Provides nutrients, anchors roots, and supplies drinking water.
Soil’s ability to absorb, release, and purify water is essential for plant health and ecosystem stability.
What is the estimated biodiversity in one hectare of soil?
Contains approximately 1020 kg of earthworms, 2700 kg of fungi, 1700 kg of bacteria, 150 kg of protozoa, and 1000 kg of arthropods and algae.
Biodiversity in soil is crucial for ecosystem functioning and nutrient cycling.
How many bacteria can one gram of soil hold?
One billion bacteria.
Only 5 percent of these bacteria have been discovered and described.
What is the significance of soil as a carbon sink?
Stores over three times more carbon than forests and other vegetation.
Soil plays a critical role in mitigating climate change.
What percentage of the world’s soil has been strongly degraded?
Seventeen percent.
Unsustainable agricultural practices are the main causes of land degradation.
How long does it take for 2.5 cm of topsoil to form?
500 to 1,000 years.
This long formation time highlights the importance of soil conservation.
What are the three main types of soil particles?
Clay, silt, and sand.
These particle sizes determine the soil texture and its properties.
What is loam soil?
A mixture of sand, silt, and clay.
Loam soils are generally more fertile and better for supporting various plant species.
What is a soil triangle used for?
To establish the kind of soil being investigated based on the percentages of each soil type.
The soil triangle helps visualize the relationship between different soil textures.
How are the percentages of soil types calculated in a sample?
By adding the soil sample to water, shaking it, allowing it to settle, and measuring the height of each layer.
This method relies on the different settling rates of soil particles.
What should the total percentage of soil types add up to when using a soil triangle?
Accurate calculations are essential for correctly identifying soil types.
True or False: Soil erosion has always occurred naturally.
True.
However, the rate of topsoil loss due to agriculture has surpassed natural formation rates since the 19th century.
What is soil air?
Trapped air between soil particles essential for soil organisms’ cellular respiration
Sandy soil has large particles and is well aerated, while clay soils are poorly aerated.
What is soil water?
Water that fills the air spaces between soil particles
Water is affected by cohesion (water attracts water) and adhesion (water attracts other substances).
How does soil type affect water drainage in sandy soils?
Sandy soils have large particles and small surface area, leading to easy drainage of water
Little adhesion of water to particles allows quick drainage.
How does soil type affect water drainage in clay soils?
Clay soils have tiny particles and large surface area, leading to poor drainage of water
High adhesion of water to particles retains water.
What is soil water retention?
The ability of soil to retain water
Different soil types retain water differently, affecting vegetation growth.
What is soil water drainage?
The ease with which water passes through soil
Quick draining soil is not suitable for water-loving plants; excessive retention can lead to waterlogging.
What is humus?
Dead and decaying organic matter in soil, rich in nutrients
Contains detritivores and decomposers, and holds onto water.
What is mulch?
Dead plant material on the soil surface that becomes humus
Provides a protective layer, preventing erosion and water loss.
What is soil pH?
A measure of how acidic or alkaline soil is
Affects chemical processes and nutrient availability for plants.
What pH range do most plants prefer?
Neutral soils with a pH of 6.5-7.5
Acidic soils are pH >6.5, alkaline soils are pH <7.5.
How can soil pH be tested?
Using a pH meter or a pH indicator
Soil must be mixed with pure water and allowed to settle before testing.
Fill in the blank: Soil water is affected by _______ and _______.
cohesion, adhesion
True or False: Humus prevents water loss from soils.
True
What role do detritivores and decomposers play in soil?
They help decompose organic matter, contributing to humus formation
Examples include earthworms, bacteria, and fungi.
What is the biosphere?
The part of the planet where organisms live, including parts of the hydrosphere, atmosphere, and lithosphere.
Often referred to as the global ecosystem.
How are the Earth’s spheres interconnected?
Changes or disturbances in one sphere affect the others.
Example: Deforestation impacts soil erosion, water quality, and atmospheric carbon dioxide.
What are biomes?
Regions with similar climate and geography characterized by specific communities of plants, animals, and microorganisms.
Biomes can be aquatic or terrestrial.
What key factors determine the climate in a biome?
Average rainfall and temperatures, influenced by geography such as latitude and altitude.
Mountains also play a significant role in climatic conditions.
What is an example of an aquatic biome?
Coral reefs, rocky shores, sandy shores, estuaries, wetlands, rivers/streams, ponds/lakes.
Each has distinct characteristics and communities.
Describe the sandy shore biome.
An intertidal zone with loose sand, waves, and tides.
Plants include washed-up seaweeds; animals include sand hoppers and sea gulls.
What types of organisms are typically found in rocky shore biomes?
Red, green, and brown seaweeds; limpets, sea snails, barnacles, mussels, sea anemones, starfish, crabs, seagulls.
This biome is very diverse.
What is unique about coral reefs?
They are found in shallow seas and consist of corals living symbiotically with algae.
Coral reefs are generally in nutrient-poor waters.
What characterizes the open ocean (pelagic) biome?
Open water dominated by floating plankton and larger animals such as fish and whales.
The seafloor beneath is referred to as the benthic zone.
What is an estuary?
Where fresh water meets salty water, often at the mouths of rivers.
Important for species like spawning fish and feeding birds.
What are wetlands?
Areas with waterlogged soil and a high water table, acting as filters and flood prevention.
They can be permanent or seasonal and host diverse wildlife.
Fill in the blank: The flowing water in rivers can be either _____ or _____.
fast; slow
What types of plants are typically found in ponds and lakes?
Floating plants (e.g., lilies), water plants, and algae.
These bodies of water include standing fresh water.
True or False: The biosphere includes only the lithosphere.
False
What are the climatic characteristics of the Savanna biome in South Africa?
Warm wet summers, cold dry winters, nutrient poor sandy soils
Which animals are commonly found in the Savanna biome?
Big five: lion, leopard, elephant, rhino, buffalo
Describe the Grassland biome’s climate and soil characteristics.
Hot summers with high rainfall, cold winters with heavy frost, sandy acidic soil
What types of grasses are found in the Grassland biome?
- Sweet grasses: nutritious in fertile soils
- Sour grasses: in less fertile areas
What is the climate of the Nama Karoo biome?
Very hot summers, cold winters with little rain and frost
What types of vegetation are found in the Nama Karoo?
Grasses, small shrubs, and annuals
What is the main characteristic of the Succulent Karoo’s climate?
Very hot dry summers, cold winters, very low winter rain
What types of plants dominate the Succulent Karoo?
Small succulents with thick fleshy leaves, e.g., vygies and stone plants
Name some animals that inhabit the Succulent Karoo.
- Bat eared fox
- Meerkat
What are the key features of the Forest biome in South Africa?
High rainfall, no frost, fertile and humus rich soil, closed canopy of trees
Which animals are typically found in the Forest biome?
- Small buck
- Bush pig
- Monkeys
- Many birds
What is the climate like in the Thicket biome?
Varies, generally more moist as it is located in the east of the country
What type of vegetation is prevalent in the Thicket biome?
- Thorn trees
- Bushes
- Some succulents
- Small forest trees
What is the Cape Floral Kingdom known for?
Dramatic and varied landscapes, astonishing diversity of habitats and species
How many plant species are recorded in the Cape Floral Kingdom?
9,600 recorded plant species
What are the main climatic features of the Fynbos biome?
Dry and hot summers, stormy, cold and wet winters, seldom with frost
What are the dominant plant families in the Fynbos biome?
- Protea family
- Restio family
- Erica family
What adaptations do Fynbos plants have to survive fire?
- Reseeding
- Resprouting
What is myrmecochory?
A seed dispersal strategy where seeds have a fleshy part to encourage ants to bury them
What is serotiny in plants?
The retention of seeds until after a fire
True or False: The Fynbos biome has nutrient-rich soil.
False
Fill in the blank: The Fynbos is one of only six ______ in the world.
Floral kingdoms
What is the size of the Cape Floral Kingdom?
Less than 90,000 km²
Comparable to the size of Malawi or Portugal.
How many plant species are found in the Cape Floral Kingdom?
9,600 plant species
Over 6,500 of these are endemic to the area.
How many plant species are found in the British Isles?
1,500 plant species
Fewer than 20 of which are endemic.
How many plant species does Tropical Africa have?
30,000 plant species
In almost 20 million km².
What designation has been given to the Cape Floral Kingdom?
One of the planet’s six plant kingdoms
Comparable to the Boreal Forest Kingdom.
What percentage of all plant species on Earth does South Africa host?
10%
Despite its area of about 1,200,000 km².
What does megadiverse mean?
Countries that together contain 70% of the planet’s biodiversity
South Africa is considered megadiverse along with 17 other countries.
What is the economic contribution of tourism in South Africa?
Estimated to bring in up to R62 billion/year
Tourism is one of the fastest-growing sectors of the economy.
How can eco-tourism help alleviate poverty?
By reinvesting earnings into communities near tourist destinations
This might support local development and livelihoods.
What types of jobs does tourism provide?
- Park operators
- Sellers of local crafts
- Guides
These jobs are essential for local economies.
What potential does eco-tourism have for communities?
Create infrastructural development
Especially useful in remote areas with major tourist locations.
Fill in the blank: South Africa has a range of ecosystems from the desert, mountain, forest, and marine systems to our own unique _______.
fynbos biome
True or False: South Africa is one of the most biodiverse countries in the world.
True
What is the size of the Cape Floral Kingdom?
Less than 90,000 km²
Comparable to the size of Malawi or Portugal.
How many plant species are found in the Cape Floral Kingdom?
9,600 plant species
Over 6,500 of these are endemic to the area.
How many plant species are found in the British Isles?
1,500 plant species
Fewer than 20 of which are endemic.
How many plant species does Tropical Africa have?
30,000 plant species
In almost 20 million km².
What designation has been given to the Cape Floral Kingdom?
One of the planet’s six plant kingdoms
Comparable to the Boreal Forest Kingdom.
What percentage of all plant species on Earth does South Africa host?
10%
Despite its area of about 1,200,000 km².
What does megadiverse mean?
Countries that together contain 70% of the planet’s biodiversity
South Africa is considered megadiverse along with 17 other countries.
What is the economic contribution of tourism in South Africa?
Estimated to bring in up to R62 billion/year
Tourism is one of the fastest-growing sectors of the economy.
How can eco-tourism help alleviate poverty?
By reinvesting earnings into communities near tourist destinations
This might support local development and livelihoods.
What types of jobs does tourism provide?
- Park operators
- Sellers of local crafts
- Guides
These jobs are essential for local economies.
What potential does eco-tourism have for communities?
Create infrastructural development
Especially useful in remote areas with major tourist locations.
Fill in the blank: South Africa has a range of ecosystems from the desert, mountain, forest, and marine systems to our own unique _______.
fynbos biome
True or False: South Africa is one of the most biodiverse countries in the world.
True
What type of ecosystem is studied in this document?
Rocky shore ecosystem
The study focuses on the interactions within rock pools.
What are biotic factors in the rocky shore ecosystem?
Species interacting within the rock pool community
This includes various organisms that coexist and interact in the environment.
What are the different feeding levels found in rocky shore ecosystems?
- Producers
- Primary consumers
- Secondary consumers
- Tertiary consumers
- Decomposers
Each feeding level plays a crucial role in the ecosystem’s energy flow.
What are the primary producers in the rocky shore ecosystem?
Algae (seaweeds)
Unlike terrestrial ecosystems where land plants are producers, oceans primarily rely on algae.
What are the three broad groups of algae found in the intertidal zone?
- Green algae
- Brown algae
- Red algae
Each group has distinct characteristics and adaptations to their environment.
What pigments do different seaweeds have, and why are they important?
They allow seaweeds to absorb different wavelengths of sunlight
This adaptation helps them maximize photosynthesis in varying light conditions.
What happens to light as it passes through water?
Certain wavelengths are absorbed and filtered, making it darker with depth
Blue and green light penetrate deeper than other wavelengths.
How do brown and red algae adapt to light conditions?
They have pigments that allow them to better absorb blue and green light
This adaptation is crucial for their survival in deeper waters.
What are the characteristics of algae species?
- Uni- or multicellular
- Encrusting or coralline
- Branched resembling land plants
These characteristics help in their survival and ecological roles.
What color are brown algae generally, and what pigments contribute to this?
Khaki-brown due to green and brown pigments
The coloration is a result of the combination of pigments present.
What are phytoplankton?
Floating microscopic plant-like plankton (algae)
They are crucial for photosynthesis in surface waters.
What role do phytoplankton play in the ecosystem?
They produce food through photosynthesis and release 70% of the world’s oxygen
This highlights their importance in global oxygen supply.
What are grazers in the context of consumers?
Primary consumers or herbivores
Grazers feed on plant material.
What types of consumers are predators?
Secondary consumers and tertiary consumers or carnivores
Predators hunt and consume other animals.
What do scavengers and detritivores consume?
Dead and decomposing materials
They recycle nutrients in ecosystems.
What are examples of grazers?
- Limpets
- Sea urchins
- Winkles
- Cushion stars
Grazers feed on algae and other plant materials.
What behavior do limpets exhibit while grazing?
They always rest in the same place on a rock
This behavior leads to reduced seaweed in that area.
Name some examples of predators.
- Whelks
- Starfish
- Anemones
- Fish
- Crabs
- Seagulls
These animals actively hunt other organisms.
What do filter feeders do?
They suck seawater through their bodies and trap floating materials
They feed on small particles like algae.
List examples of filter feeders.
- Sponges
- Mussels
- Barnacles
These organisms play a role in filtering water.
What is zooplankton?
Tiny microscopic floating animals or animal-like cells
They are a crucial part of the aquatic food web.
What forms the animal component of plankton?
- Protozoa
- Eggs
- Larvae
- Shrimps
- Other tiny crustaceans
These organisms feed on phytoplankton.
What role do bacteria play in marine ecosystems?
They are the main decomposers in the oceans
Bacteria break down organic molecules, recycling nutrients.
What do decomposers do?
Break down organic molecules to release nutrients
This process supports other organisms like algae.
What type of organisms also act as decomposers in seawater?
Some types of fungi
Fungi contribute to nutrient cycling in marine environments.
What are grazers in the context of consumers?
Primary consumers or herbivores
Grazers feed on plant material.
What types of consumers are predators?
Secondary consumers and tertiary consumers or carnivores
Predators hunt and consume other animals.
What do scavengers and detritivores consume?
Dead and decomposing materials
They recycle nutrients in ecosystems.
What are examples of grazers?
- Limpets
- Sea urchins
- Winkles
- Cushion stars
Grazers feed on algae and other plant materials.
What behavior do limpets exhibit while grazing?
They always rest in the same place on a rock
This behavior leads to reduced seaweed in that area.
Name some examples of predators.
- Whelks
- Starfish
- Anemones
- Fish
- Crabs
- Seagulls
These animals actively hunt other organisms.
What do filter feeders do?
They suck seawater through their bodies and trap floating materials
They feed on small particles like algae.
List examples of filter feeders.
- Sponges
- Mussels
- Barnacles
These organisms play a role in filtering water.
What is zooplankton?
Tiny microscopic floating animals or animal-like cells
They are a crucial part of the aquatic food web.
What forms the animal component of plankton?
- Protozoa
- Eggs
- Larvae
- Shrimps
- Other tiny crustaceans
These organisms feed on phytoplankton.
What role do bacteria play in marine ecosystems?
They are the main decomposers in the oceans
Bacteria break down organic molecules, recycling nutrients.
What do decomposers do?
Break down organic molecules to release nutrients
This process supports other organisms like algae.
What type of organisms also act as decomposers in seawater?
Some types of fungi
Fungi contribute to nutrient cycling in marine environments.
What are abiotic factors?
Non-living components that influence ecosystems
Includes sunlight, temperature, and rock types.
What is the effect of wave action on rocky shore ecosystems?
Erosion of rocks and organisms, mixing of oxygen into water, and nutrient churn
Strong wave action can benefit filter feeders but also cause damage.
List advantages of wave action.
- Churns up sediments containing food and nutrients
- Mixes oxygen into water
These advantages support various marine organisms.
List disadvantages of wave action.
- Erosion of rocks over time
- Can tear organisms off rocks
These disadvantages can impact the survival of marine life.
What are some behavioral adaptations of organisms to wave action?
- Sheltering in crevices
- Living high up on the shore
These behaviors help organisms avoid the harsh effects of waves.
What structural adaptations help organisms survive wave action?
- Flattened or streamlined shape
- Producing cement (e.g., barnacles)
- Byssus threads (e.g., mussels)
- Large foot (e.g., limpets)
- Ability to roll in waves (e.g., periwinkles)
- Cylindrical or spherical seaweeds
These adaptations reduce resistance and improve adherence to rocks.
How do different rock types affect rocky shore ecosystems?
They influence the structure and availability of habitats
Examples include granite boulders and sedimentary platforms.
What are rock pools?
Unique ecosystems formed in crevices and cracks of rocks
They have variable temperature, salinity, pH, and dissolved gases.
Why does seawater temperature change less quickly than air temperature?
Water has a very high specific heat capacity
It takes a lot of energy to change the temperature of water.
What temperature variations can occur in rock pools?
Wide range of temperatures due to isolation from sea
Rock pools heat quickly during the day and cool rapidly at night.
Fill in the blank: Organisms in rock pools must be able to cope with a _______ range of temperatures.
[wide]
This adaptability is crucial for survival in fluctuating conditions.
What is salinity?
The amount of salt in seawater
How does salinity change in rock pools?
It changes dramatically as water evaporates or is replaced by fresh seawater
What happens to marine animals if salinity rises too high in rock pools?
They must abandon the pool or die
Why are pools near the top of the shore dangerous for marine life?
They can be isolated from the sea for long periods
What is the relationship between pH and rock pool communities?
There is a close relationship between the community and the pH of the water
What effect does dissolved carbon dioxide have on water pH?
It makes the water more acidic
What happens to carbon dioxide levels during photosynthesis?
Carbon dioxide is used up, making the water less acidic
What occurs at night regarding pH in rock pools?
Photosynthesis does not occur, leading to increased carbon dioxide and acidity
True or False: Organisms that are sensitive to acidic water can live in rock pools.
False
How is dissolved oxygen replenished in the water?
Through photosynthesis, wave action, or simple diffusion
What happens to oxygen levels in rock pools at low tide, especially at night?
Oxygen can become depleted
Why is it important for organisms in rock pools to cope with a wide range of dissolved oxygen levels?
To survive when oxygen levels are low
What causes tidal action?
The gravitational effect of the moon and the sun
Fill in the blank: Tidal action causes water to ______ outward.
bulge
How often does the tide rise and flood the shore?
Twice a day
What causes the water to ‘bulge’ on the side of the Earth facing the moon?
The gravitational pull of the moon.
What phenomenon occurs on the side of the Earth opposite to the moon?
High tide due to centrifugal force.
How many high tides and low tides does a location on Earth experience in a 24-hour period?
Two high tides and two low tides.
What are spring tides?
Tides that occur when the sun, moon, and Earth are in a straight line, resulting in extra high and low tides.
When do spring tides occur?
One full day after a new moon or a full moon.
What are neap tides?
Tides that occur when the sun and moon are at right angles to each other, resulting in minimal difference between high and low tides.
What is the approximate time difference for high and low tides due to the moon’s cycle?
About 50 minutes later each day.
What adaptations do organisms in intertidal zones have to prevent drying out? (List any two)
- Behavioral characteristics such as sheltering in pools or under seaweeds
- Structural adaptations like minimising water loss with a small surface area
How do winkles minimize water loss?
By having a small surface area:volume ratio and using an operculum to trap water.
Where are limpets typically found in relation to the low water mark?
Near the low water mark of the spring low tide.
True or False: All high tides are of equal height.
False.
Fill in the blank: The ________ force pushes water away from the surface of the Earth.
centrifugal
What is one method some algae use to protect their cells?
Producing slimy secretions or jelly-like mucous.
What happens to the height of high tides and low tides over a month?
They vary in height due to the positions of the Moon and Sun.
What factors influence the distribution of species on rocky shores?
The amount of sunlight, tidal range, and exposure to air
These factors determine species tolerance and survival.
What is the Supralittoral Zone?
The splash/drift zone always above the water
This zone is characterized by minimal submersion.
What characterizes the Littoral Zone?
The area sometimes under water and sometimes exposed
This zone experiences varying levels of water coverage.
What is the Littorina Zone?
Covered at spring high tide
This zone is specifically influenced by the highest tides.
What is the Upper Balanoid Zone (barnacle zone)?
Covered at neap high tide and above average sea level
This zone is primarily inhabited by barnacles.
What is the Lower Balanoid Zone (mussel zone)?
Exposed at neap low tide
This zone is typically dominated by mussels.
What is the Cochlear Zone (limpet zone)?
Exposed at spring low tide
This zone is characterized by the presence of limpets.
What is the Sublittoral Zone?
Always below the water
This zone is sub-tidal and remains submerged.
True or False: Each species on the rocky shore has a fixed tolerance to environmental factors.
True
Tolerance determines the survival of species in various zones.
Fill in the blank: The _______ Zone is characterized by being always above the water.
Supralittoral Zone
This zone is affected by splash and drift.
What determines where a species can survive on a rocky shore?
How tolerant a species is to varying environmental factors
Species with specific tolerances will occupy certain zones.
