Ecosystem Dynamics Quiz

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Questions and Answers

What defines a population in an ecosystem?

All populations interacting in a specific environment

The total number of species in an ecosystem

A group of individuals from the same species living in the same area (correct)

All living organisms in a given area

Which of the following accurately describes an ecosystem?

A community and its physical and chemical environment (correct)

Only the living organisms in an area

A group of distinct communities within a geographical space

The abiotic components of an area without any living organisms

In a food chain, what role does a primary consumer play?

They consume primary producers (correct)

They are at the top of the food chain

They feed on secondary consumers

They produce their own food

What is the main difference between a food chain and a food web?

Food chains are less complex than food webs Signup and view all the answers

Which statement about trophic levels is true?

Autotrophs are found in the first trophic level Signup and view all the answers

What happens to an ecosystem if there is a significant increase or decrease in the population of one species?

It can cause a cascading effect throughout the ecosystem Signup and view all the answers

What is the primary characteristic of heterotrophs?

They rely on consuming other organisms for energy Signup and view all the answers

Which term refers to the variety of species present within an ecosystem?

Biodiversity Signup and view all the answers

What term describes the sequence of organisms that feed on one another?

Food chain Signup and view all the answers

Which of the following are abiotic factors in an ecosystem?

Weather and temperature Signup and view all the answers

What is the main mechanism through which natural selection operates?

Survival of individuals with more favorable variations Signup and view all the answers

What type of mutation is likely to enhance an individual's fitness?

Beneficial mutations Signup and view all the answers

Which of the following statements about mutations is true?

Mutations can be caused by environmental factors Signup and view all the answers

How does sexual reproduction contribute to genetic variation?

It introduces random gene combinations into offspring Signup and view all the answers

What is meant by 'fitness' in the context of evolution?

An organism's ability to survive and reproduce Signup and view all the answers

Why are harmful mutations less likely to be present in future generations?

They are selected against in the process of natural selection. Signup and view all the answers

What is a likely effect of beneficial mutations over generations?

They accumulate and become more common. Signup and view all the answers

Which of the following describes the randomness in gene combination during sexual reproduction?

Each offspring receives a random assortment of genes from each parent. Signup and view all the answers

What effect does increasing temperature have on enzyme reactions up to a certain point?

Increases the number of reactions. Signup and view all the answers

At what temperature are human enzymes optimally adapted to function?

37°C Signup and view all the answers

What is the consequence of pH values being away from an enzyme's optimal range?

The enzyme becomes denatured. Signup and view all the answers

How does feedback inhibition work in enzyme activity?

It turns off an enzyme via its end product. Signup and view all the answers

What happens to the reaction rate when there are more substrate molecules available?

It increases until enzyme availability limits it. Signup and view all the answers

Which part of the human digestive system is involved in mechanical digestion?

Mouth Signup and view all the answers

Where is pepsin primarily active in the human digestive system?

Stomach Signup and view all the answers

What role do accessory organs play in digestion?

They aid digestion but do not handle food directly. Signup and view all the answers

What is the first step in allopatric speciation?

A physical barrier separates a population Signup and view all the answers

In which part of the chloroplast does photosynthesis primarily occur?

Thylakoids Signup and view all the answers

What is the primary output of the light-dependent reactions of photosynthesis?

ATP and NADPH Signup and view all the answers

What constitutes the inputs for the light-independent reactions (Calvin Cycle)?

NADPH, ATP, and carbon dioxide Signup and view all the answers

How are ATP molecules produced during the light-dependent reactions?

Using an electrochemical gradient of hydrogen ions Signup and view all the answers

What does gradualism in speciation suggest?

Speciation occurs at a slow, steady pace Signup and view all the answers

What process occurs during photolysis in photosynthesis?

Water is split into hydrogen ions and oxygen Signup and view all the answers

During cellular respiration, what is the primary energy currency produced?

ATP Signup and view all the answers

Which molecule acts as the electron carrier in the light-dependent reactions?

NADP+ Signup and view all the answers

What type of barrier is essential for allopatric speciation to occur?

Physical barrier Signup and view all the answers

What happens to the glucose produced in photosynthesis?

It may be stored for energy or used in cellular respiration Signup and view all the answers

Which of the following processes involves the conversion of light energy into chemical energy?

Photosynthesis Signup and view all the answers

In the light-dependent reactions, what is generated as a byproduct?

Oxygen Signup and view all the answers

What is the primary role of ATP in cellular processes?

Usable form of energy for cells Signup and view all the answers

What role does paleontology play in the study of evolution?

It provides evidence through the study of fossils. Signup and view all the answers

Which of the following correctly describes homologous features?

They share an evolutionary origin but may serve different functions. Signup and view all the answers

What key concept is supported by the fossil record in evolution?

Fossils can illustrate species' changes over long periods. Signup and view all the answers

Which evidence of evolution deals with the geographical distribution of species?

Biogeography Signup and view all the answers

What does artificial selection demonstrate about evolution?

It provides evidence that dramatic changes can occur over time. Signup and view all the answers

What misconception was associated with Lamarckism?

Acquired traits can be inherited by offspring. Signup and view all the answers

How much genetic similarity do humans share with chimpanzees?

96% Signup and view all the answers

What are vestigial features?

Structures that have lost their apparent use but have an evolutionary origin. Signup and view all the answers

What is the significance of studying embryology in evolutionary biology?

It shows the similarities in early development stages among different species. Signup and view all the answers

What important aspect of evolution does biochemistry provide evidence for?

The similarities and differences in DNA among species. Signup and view all the answers

What is the role of bicarbonate ions in the digestive process?

They neutralize HCl from the stomach. Signup and view all the answers

What is the function of trypsin in the small intestine?

It breaks long chain polypeptides into shorter peptides. Signup and view all the answers

Which enzyme is responsible for the final digestion of proteins into amino acids?

Erepsin Signup and view all the answers

What is the primary role of bile salts in fat digestion?

They emulsify fat globules to increase surface area. Signup and view all the answers

Where does the absorption of carbohydrates primarily occur?

In the small intestine Signup and view all the answers

What is the purpose of the diaphragm during breathing?

It facilitates the movement of air in and out of the lungs. Signup and view all the answers

Which part of the respiratory system is responsible for gas exchange?

Alveoli Signup and view all the answers

What characterizes bronchitis?

Narrowing of bronchial tubes Signup and view all the answers

Which muscle type is voluntary and striated?

Skeletal muscle Signup and view all the answers

What happens during expiration?

The diaphragm relaxes and moves up. Signup and view all the answers

What process is primarily involved in the physical digestion of lipids?

Emulsifying by bile salts Signup and view all the answers

What is the main cause of emphysema?

Smoking Signup and view all the answers

Which best describes the role of the intercostal muscles?

They move the rib cage during breathing. Signup and view all the answers

Study Notes

Bio 20 Units A, B, C, and D1 Crash Course

Bio 20 is a course covering Units A, B, C, and D1.
Effective note-taking is crucial; research indicates a 34% chance of remembering key concepts if noted, compared to only 5% if not.
Choose a note-taking strategy you find useful, whether it’s summaries, visual aids, or diagrams.

Earth's Spheres

The biosphere is the narrow zone around Earth that harbors life.
The biosphere extends from the bottom of the ocean into the atmosphere.

Components of the Biosphere

The biosphere consists of biotic and abiotic factors.
Biotic factors are living things, including plants and animals.
Abiotic factors are nonliving things, including rocks, minerals, temperature, and weather.

Terminology

A population is a group of individuals from the same species living in the same area.
A community is all the populations in a given area, encompassing all living things.
An ecosystem includes both biotic and abiotic components, encompassing the community of organisms and its physical and chemical environment.
Biodiversity is the number of species in an ecosystem.

Food Chains

A food chain links organisms that feed on each other.
It starts with producers (making their own food), followed by primary, secondary, and tertiary consumers.
Organisms that feed on secondary consumers are known as tertiary consumers.
Decomposers are also part of the chain.

Food Webs

Food webs show feeding relationships in an ecosystem, including multiple food chains.
They're more realistic representations of ecosystems than food chains.

Trophic Levels

Trophic levels categorize organisms by how they obtain energy.
The first trophic level contains autotrophs (producers).
Higher trophic levels contain heterotrophs (consumers).
Autotrophs produce their own food.
Heterotrophs consume other organisms or organic material for energy.

Energy Transfer

Only about 10% of energy at a given trophic level is passed to the next.
The rest is lost as heat.

Thermodynamics

Thermodynamics studies energy transformations.
The first law states that energy cannot be created or destroyed, only transformed.
The second law indicates during any transformation, some energy is converted to thermal energy (heat).

Photosynthesis

Photosynthesis is used by green plants to turn solar energy, carbon dioxide, and water into glucose.
This process supports the entire ecosystem.
More green plants translate to more energy in the ecosystem

Cellular Respiration

Cellular respiration is the breakdown of glucose to release energy in the form of ATP.
All organisms, including plants, use this process.
ATP (adenosine triphosphate) is the main fuel source in organisms.

Chemosynthesis

Chemosynthesis, unlike photosynthesis, doesn't rely on solar energy.
Deep-sea environments contain chemoautotrophs that convert inorganic chemicals into organic compounds.

Water Cycle

Includes stages like evaporation, transpiration, condensation, precipitation, and runoff.

Ground Water/Surface Water

Percolation is the downward movement of water through soil, carrying dissolved organic matter.
Leaching is a related process.

Carbon Cycle

Processes like photosynthesis, cellular respiration, combustion, decomposition, sedimentation, and uplifting move carbon.

Earth's Atmosphere

The composition of Earth's atmosphere has changed over time.
Early atmosphere contained water vapor, carbon dioxide, and other gases.
The modern atmosphere is primarily nitrogen and oxygen.

The Nitrogen Cycle

Key processes in the nitrogen cycle include nitrogen fixation, nitrification, assimilation, and denitrification, all performed by bacteria.

Phosphorus Cycle

A cyclical process where phosphorus is found in rocks, fossils, and sediments.
The cycle also includes short-term absorption by plants and animals.

Ecotones

Ecotones are transition zones between ecosystems.
They show a mixture of organisms and conditions from neighboring ecosystems.
In ecotones, biodiversity is often higher.

Ecological Niches

An ecological niche describes an organisms role in its ecosystem.
It includes its place in the food web, habitat, breeding area, activity time, and necessary survival and reproduction actions.
Different species occupy different niches to avoid competition for resources.

Biomes

Biomes are large areas of similar climate.
Canada has four major terrestrial biomes: tundra, taiga, temperate deciduous forest, and grasslands.

Taiga Ecosystem

Taiga is a boreal forest of coniferous trees.
Conifers are well adapted to the cold, dry winters and warm, moist summers of this biome.
These trees have adaptations like needles for water retention and pyramid shapes for snow shedding.
Soil in taiga ecosystems is slightly acidic with varying water content.

Grassland Ecosystem

Grassland ecosystems are rich in fertile soil, have warmer temperatures, yet low precipitation.
Grasses and other plants adapted for lower precipitation flourish.

Deciduous Forest Ecosystem

This ecosystem is situated between grasslands and taigas in central Alberta.
Deciduous trees like poplars, birches, and aspens dominate.
Soils are rich and fertile and precipitation is moderate.

Tundra

Tundra is Earth's most northern and coldest biome.
It has low precipitation and few trees.
Animals like polar bears, arctic foxes, and caribou inhabit the region.

Tropical Rainforest

Located near the equator, the tropical rainforest is known for high biodiversity.
High temperatures and rainfall values make it a productive ecosystem.

Forestry Practices

Slash and burn and clear cutting are common forestry practices to harvest timber.
Consequences of these methods include soil erosion, loss of biodiversity, and changes to water quality.

Selective Cutting

A more sustainable method of harvesting timber while retaining some mature trees and promoting natural regeneration.

Lake Types

Oligotrophic lakes are deep, cold, and have low nutrient levels.
Eutrophic lakes are shallow, warm, and have high nutrient levels.

Taxonomy

Taxonomy is the science of classifying organisms.
The current system uses eight or more levels.

Binomial Nomenclature

This is a system for naming organisms using two parts: Genus and species (e.g., Homo sapiens).

Evolution

Evolution is the theory for how organisms change over time.
A theory accounts for all observed scientific evidence.

Evidence of Evolution

Fossils—the remains of past life.
Biogeography—the study of the distribution of plants and animals.
Anatomy—comparing the structures of organisms and seeing common ancestors.
Embryology—comparing the early developmental stages.
Artificial Selection—human-induced changes in plants and animals.
Biochemistry—comparing genetic material and similarities in organisms.

Lamarckism

Lamarck proposed the principle of inheritance of acquired characteristics; though incorrect, it was an early idea on evolutionary adaptations

Theory of Evolution by Natural Selection

Individuals within a species constantly struggle for survival.
Those with traits better suited to their environment are more likely to survive and reproduce.
Favorable traits then become more common in the population over successive generations.

Source of Variation

Mutations—changes in DNA can create new traits.
Sexual Reproduction - mixing of parental genes produces unique combinations of traits.

Allopatric Speciation

Speciation occurs when a population physically separates—leading to variations due to natural selection—forming new species.

Rate of Speciation

Gradualism suggests speciation occurs gradually.
Punctuated Equilibrium speculates rapid bursts of change followed by periods of stability.

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Description

Test your knowledge on the fundamental concepts of ecosystems, including populations, food chains, and food webs. This quiz will challenge your understanding of trophic levels, natural selection, and the role of different species within an ecosystem.