Ecology Biology Final

Animals

Animals utilize and break down materials from bacteria, plants and fungi and return the nutrients to soils and water via their wastes and when they die.

what does a Sustainable Ecosystem require?

Continuous energy availability, e.g. light from the sun Nutrient cycling - saprotrophs are crucial for continuous provision of nutrients to producers Recycling of waste - certain by products of metabolism

How are pigments used in photosynthesis?

Photosynthesis in plants is dependent upon capturing light energy in the pigment chlorophyll.

Photosynthesis, key idea

Photosynthesis is the process of converting sunlight, carbon dioxide, and water into glucose and oxygen.

What are autotrophs/heterotrophs?

Plants are the prime example of autotrophs, using photosynthesis. All other organisms must make use of food that comes from other organisms in the form of fats, carbohydrates and proteins. These organisms which feed on others are called heterotrophs.

What is at the base of all ecological pyramids?

Producers

Outline why sampling must be random.

To avoid bias in selection of samples

What is the term for each step in the transfer of energy and matter within a food web?

Trophic level, which comprises of levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.

How do most primary producers make their own food?

Usually, primary producers such as plants use photosynthesis. Photosynthesis converts water, the sun's energy, and carbon dioxide into glucose and oxygen. The oxygen is released and the glucose is used to be converted into ATP through cellular respiration.

Define nutrient.

a substance that provides nourishment essential for growth and the maintenance of life

Describe the feeding behaviors of detritivores.

consume nonliving organic sources humus is decaying leaf litter mixed with the soil detritus dead, particulate organic matter. This includes decaying organic material and fecal matter

Detritus

dead, particulate organic matter. This includes decaying organic material and fecal matter

Humus

decaying leaf litter mixed with the soil

List two example detritivore organisms.

earthworms dung beetles

List three example consumer organisms.​

herbivores Omnivores carnivores

Explain what a null and alternative hypothesis can be used for.

null:There is no significant difference between the distribution of two species (i.e. distribution is random) alternative:There is a significant difference between the distribution of species (i.e. species are associated)

What animals eat both producers and consumers?

Omnivores

What is an ecological model of the relationships that form a network of complex feeding interactions among organisms in a community from producers to decomposers?

a food web

Define species according to the biological species concept.

a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance

Steps of Cell Respiration

1. Glycolysis. In the cytoplasm, glucose is broken down into two molecules of pyruvate. 2. The link reaction. Pyruvate is split and added to coenzyme A ready to enter the Krebs cycle. 3. Krebs cycle. In the mitochondrial matrix, a derivative of pyruvate is decomposed to CO2. 4. Electron transplant chain. This occurs in the inner membranes of the mitochondrion and accounts for almost 90% of the ATP generated by respiration.

Bacteria

Bacteria play an essential role in nutrient cycles. They act as decomposers, but can also convert nutrients into forms accessible to plants and animals.

Factors affecting rate of photosynthesis

1. light intensity More light → higher photosynthetic rate 2. CO2 concentration More CO2 → higher photosynthetic rate 3. Temperature There is an optimum temp → pretty high / plant dies off if it is too hot, can't be too hot or too cold (water in plant will freeze, plant leaves will die)

Outline three requirements of a sustainable ecosystem.

1. nutrient availability 2. detoxification of waste products 3. energy availability

photosynthesis equation

6CO2 + 6H2O → sunlight → C6H12O6+ 6O2

Autotrophs nutrient cycling

Autotrophs convert nutrients from inorganic form into organic molecules, e.g. carbon dioxide becomes glucose

cell respiration equation

C6H12O6+6O2 → respiration → 6CO2+6H2O

A bird stalks, kills, and then eats an insect. Based on its behavior, what are ecological terms that could describe the bird?

Carnivore Secondary consumer heterotroph

Cell Respiration

Cell respiration is the process by which the energy in glucose is transferred to ATP. Glucose + Hydrogen →Carbon dioxide + Water + Energy C6H12O6 + 6O2 →6CO2 + 6H2O + Energy

How are photosynthesis and cellular respiration part of the carbon cycle?

Cellular respiration and photosynthesis are important parts of the carbon cycle. The carbon cycle is the pathways through which carbon is recycled in the biosphere. While cellular respiration releases carbon dioxide into the environment, photosynthesis pulls carbon dioxide out of the atmosphere.

classification of consumers

Consumers use a range of different food sources and feeding mechanisms. The combination of food source and feeding mechanism can be used to classify consumers. Primary consumer: herbivore Secondary consumer: carnivore/omnivore Tertiary consumer: top carnivore

Energy Losses

Energy released from carbon compounds by respiration is used in living organisms and converted to heat Energy stored in organic molecules (e.g. sugars and lipids) can be released by cell respiration to produce ATP This ATP is then used to fuel metabolic reactions required for growth and homeostasis A by-product of these chemical reactions is heat (thermal energy), which is released from the organism

Fungi

Fungi are saprophytes and are important decomposers, returning nutrients to the soil or converting them into forms accessible to plants and animals.

Number of ATP molecules per molecule of glucose generated during each stage of respiration:

Glycolysis: 2 Krebs Cycle: 2 Electron transport chain: 34 Total: 38

Why do plants appear green in sunlight?

Green plants are green because they contain a pigment called chlorophyll. Chlorophyll absorbs certain wavelengths of light within the visible light spectrum. Green light is not absorbed but reflected, making the plant appear green. Chlorophyll is found in the chloroplasts of plants.

Know how to identify the impacts of removing species from a food web on the other organisms in the food web.

If one species in the food web ceases to exist, one or more members in the rest of the chain could cease to exist too. A plant or animal doesn't even have to become extinct to affect one of its predators. The harelip sucker fish, for example, used to eat snails in the 19th century. After waste, topsoil and other debris invaded rivers where the fish lived, the snail population dwindled. The U.S. Geological Survey notes that this decline probably caused the fish to go extinct. Green plants that can make their own food through photosynthesis are the web's producers. They form the bottom of the chain. Animals that get food from other animals and plants are consumers. Decomposers feed off dead plants and animals because decomposers cannot make their own food. Every member in the food web is a predator, prey or both. For instance, one predator may become the prey for another predator.

Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. What is the remaining 90% used for?

It is eliminated as heat.

Sustainable Ecosystems

Most flows of energy and nutrients in an ecosystem are between members of the biotic community flows of energy and nutrients enter or leave from surrounding ecosystems

How do cellular respiration and photosynthesis compare?

Photosynthesis and cellular respiration are complementary processes by which living things obtain needed substances. They both consume and create the same substances (water, glucose, oxygen, and carbon dioxide) but in different ways. Through these processes, plants obtain the carbon dioxide they need and living organisms obtain the oxygen they need. They are also necessary to the energy exchange that living things need to survive. Photosynthesis is the process by which green plants create their own food by turning light energy into chemical energy. Chlorophyll in the leaves transform carbon dioxide, water, and minerals into oxygen and glucose. Photosynthesis takes place in the chloroplasts of cells. This process is what gives energy to all living organisms either directly or indirectly. Cellular respiration, on the other hand, is the process by which living things convert oxygen and glucose to carbon dioxide and water, thereby yielding energy. It does not require the presence of sunlight and is always occurring in living organisms. Cellular respiration takes place in the mitochondria of cells. While photosynthesis requires energy and produces food, cellular respiration breaks down food and releases energy. Plants perform both photosynthesis and respiration, while animals can only perform respiration.

why is photosynthesis important?

Photosynthesis is important to living things because it transforms sunlight energy into chemical energy stored in molecules, releases free oxygen gas, and absorbs carbon dioxide (a waste product of cellular metabolism). Photosynthetic organisms use special pigments, called chlorophylls, to absorb light of specific wavelengths and capture the light energy. Like cellular respiration, photosynthesis is a redox process, but in photosynthesis, water is split and electrons are transferred together with hydrogen ions from water to CO2, reducing it to sugar.

Where do photosynthesis and cellular respiration occur?

Photosynthesis takes place inside plant cells in small things called chloroplasts. Cellular respiration takes place in the mitochondria.

Plants

Plants have a role in absorbing nutrients from the soil and making them directly available to browsing animals. They also add to their own decaying matter to soils.

What organisms make up the beginning of every food chain?

Producers, because as autotrophs they produce their own food/nutrients which when other organisms eat them, they are providing these organisms with energy.

Positive association

Species found in the same habitat. e.g. predator - prey, herbivore & plant, symbiosis

No association

Species occur as frequently apart as together.

Negative association

Species occur separately in differing habitats. e.g. competitive exclusion, require different nutrients

What is the main energy source that drives photosynthesis?

Sunlight

Energy Sources

Sunlight in the initial energy source Energy flows through the food chain being lost at each stage due to respiration Nutrients are recycled

habitat

The environment in which a species normally lives The location of a living organism Ex: a puma could have the right amount of food (deer, porcupine, rabbits, and rodents), water (a lake, river, or spring), and shelter (trees or dens on the forest floor)

Outline the generalized flow of nutrients between the abiotic and biotic components of an ecosystem.

The living things in an ecosystem are called biotic factors. Living things include plants, animals, bacteria, fungi and more. The nonliving parts of an ecosystem are called abiotic factors. In an ecosystem some abiotic factors are sunlight, temperature atmospheric gases water and soil.

What are the products and reactants of photosynthesis/cellular respiration?

The reactants of photosynthesis are water and carbon dioxide which are used with light energy to produce glucose and oxygen. The reactants of cellular respiration are oxygen and glucose used to make ATP. The main product of cellular respiration is ATP, waste products include carbon dioxide and water. Products of photosynthesis are glucose sugar and oxygen gas.

ecology

The study of relationships between living organisms and their environment/ecosystem.

Nutrient Cycling

The supply of inorganic nutrients is maintained by nutrient cycling. Elements required by an organism for growth and metabolism are regarded as nutrients

Scavengers

are specialised carnivores that feed mostly on dead and decaying animals Hyenas, vultures, crows

examples of autotrophs, consumers, detritivores, and saprotrophs

autotrophs: plants, algae, and even some bacteria consumers: rabbits, bears, giraffes, flies, humans, horses, and cows detritivores: millipedes, dung beetles, earthworms, fiddler crabs and sea cucumbers saprotrophs: fungus, mushroom and moss

Define sustainability.​

avoidance of the depletion of natural resources in order to maintain an ecological balance

List two example saprotroph organisms.

bacteria and fungi

Saprotrophs nutrient cycling

breakdown organic nutrients to gain energy and in the process release nutrients back into inorganic molecules, e.g. fungi release nitrogen as ammonia into the soil. This ensures the continuing availability of nutrients to autotrophs. The supply of nutrients is limited and therefore ecosystems constantly recycle the nutrients between organisms.

Describe limitations of the biological species concept.

cannot be applied to asexual organisms, fossils, and organisms where little is known about their reproduction

List four common nutrients needed by organisms.

carbon hydrogen oxygen Other nutrients needed by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur

Explain why chemical nutrients can be recycled but energy cannot.

chemical elements are continually recycled within ecosystems Law of Conversation energy cannot be recycled

Define abiotic and ecosystem.

ecosystem: a biological community of interacting organisms and their physical environment abiotic: physical rather than biological; not a living organisms (like a rock)

How do the movements of energy and nutrients through living systems differ?

energy flows in one direction, and nutrients recycle. energy is limited in the biosphere, and nutrients are always available

Mixotrophs

few plants and algae use a combination of different modes of nutrition and are hence known Venus flytrap (Dionaea muscipula) is found in subtropical wetlands and like most plants photosynthesise (autotroph), but also traps and digests both insects and spiders (heterotroph), to compensate for the nutrient poor soil of the wetlands

Give an example of a community of organisms.

include plants and microbes and hence often involve thousands of species a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community

Describe the feeding behaviors of consumers.

ingest other organisms obtaining their organic molecules

Heterotrophs nutrient cycling

ingest other organisms to gain organic forms of nutrients

population

is a group of organisms of the same species that are living in the same area at the same time

what are the two photosynthetic reactions?

light dependent and light independent

Describe the feeding behaviors of saprotrophs.

live on, or in, non-living organic matter. They secrete digestive enzymes on to the organic matter and absorb the products of digestion digestion is external as enzymes are secreted

Explain methods of random sampling, including the use of a quadrat

methods are used to avoid bias in the selection of samples Quadrat sampling can be used in a number of ways including: Estimation of population density/size Measuring the distribution of species

what do Nutrient cycles do in the ecosystem?

move and transfer chemical elements (e.g. carbon, hydrogen, nitrogen, and oxygen) through the abiotic and biotic components of an ecosystem. Commonly, nutrients must be in an ionic (rather than elemental) form in order for plants and animals to have access to them. The supply of nutrients in an ecosystem is finite and limited.

heterotroph

obtain their organic molecules from other organisms

Give two examples of an unsustainable practice.

pollution of land, water and air are not 'renewable' resources oil, gas, electricity, steel, coal, food/plant products, etc.

Define species, population and community.

species: a group of organisms that can interbreed to produce fertile offspring population: a group of organisms of the same species that are living in the same area at the same time community: a group of populations that are living and interacting together in the same area

autotroph

synthesise their own organic molecules and are therefore known as producers

Why can matter recycle through the biosphere?

the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms. Like water, nutrients pass through organisms and the environment through biogeochemical cycles

Outline how nutrients enter living systems.

water and air penetrate soil then plant/animal matter breaks down into soil then decomposers break down matter while rocky subsoil breaks down providing nutrients to soil soil stored nutrients which plants absorb nutrients to grow