Bio Test

Question 1

What is a biogeochemical cycle?

Answer 1

A process where elements like carbon, nitrogen, and phosphorus cycle through the biosphere, atmosphere, hydrosphere, and lithosphere.

Question 2

How does matter move in ecosystems?

Answer 2

Matter is recycled in biogeochemical cycles, unlike energy which flows and is lost.

Question 3

What are the major biogeochemical cycles?

Answer 3

Carbon, nitrogen, phosphorus, sulfur, and water cycles.

Question 4

Why is the water cycle important?

Answer 4

It distributes water essential for life and regulates climate and weather patterns.

Question 5

How is the nitrogen cycle disrupted by humans?

Answer 5

Fertilizer use and fossil fuel combustion increase nitrogen in ecosystems, causing eutrophication and pollution.

Question 6

Why is phosphorus a limiting nutrient?

Answer 6

It is often scarce in ecosystems but essential for DNA, ATP, and cell membranes.

Question 7

What are key processes of the carbon cycle?

Answer 7

Photosynthesis, respiration, decomposition, combustion, sedimentation, and volcanic activity.

Question 8

How are humans affecting the carbon cycle?

Answer 8

Burning fossil fuels and deforestation increase CO₂ levels and reduce carbon sequestration.

Question 9

Why is CO₂ accumulation a concern?

Answer 9

It enhances the greenhouse effect, leading to climate change.

Question 10

What is the Keeling Curve?

Answer 10

A graph that shows the ongoing increase in atmospheric CO₂ levels since 1958.

Question 11

What human activities reduce carbon sinks?

Answer 11

Deforestation and land degradation limit CO₂ absorption by plants and soil.

Question 12

What causes anthropogenic climate change?

Answer 12

Human activities like fossil fuel burning and land use change.

Question 13

What are major effects of climate change?

Answer 13

Rising temperatures, sea level rise, extreme weather, shifting species ranges.

Question 14

What is the greenhouse effect?

Answer 14

A natural process where gases like CO₂ trap heat in the atmosphere, keeping Earth warm.

Question 15

How has climate changed since the Industrial Revolution?

Answer 15

CO₂ levels have risen from 280 ppm to over 420 ppm, increasing global temperatures.

Question 16

How does climate change alter species distributions?

Answer 16

It forces species to shift ranges, which may be blocked by habitat fragmentation.

Question 17

What is eutrophication?

Answer 17

Nutrient enrichment, often from nitrogen or phosphorus, leading to algal blooms and hypoxia.

Question 18

What causes eutrophication?

Answer 18

Fertilizer runoff, sewage discharge, and animal waste.

Question 19

What are the consequences of eutrophication?

Answer 19

Algal blooms, oxygen depletion (hypoxia), fish kills, and biodiversity loss.

Question 20

How can eutrophication be reduced?

Answer 20

By reducing nutrient runoff through better farming practices and wastewater treatment.

Question 21

What causes acid precipitation?

Answer 21

SO₂ and NOx from fossil fuel combustion mix with water to form acids.

Question 22

How does acid rain affect ecosystems?

Answer 22

It acidifies soils and lakes, leaches nutrients, and harms organisms.

Question 23

What areas are most affected by acid rain?

Answer 23

Regions downwind from industrial centers, especially eastern U.S. and parts of Europe.

Question 24

How can acid rain damage buildings?

Answer 24

It corrodes structures made of limestone and marble due to chemical reactions.

Question 25

How do these changes affect ecosystems?

Answer 25

They reduce biodiversity, disrupt food chains, and degrade habitat quality.

Question 26

How do these issues impact people?

Answer 26

They affect food security, water quality, health, and economic systems.

Question 27

How does biodiversity loss affect ecosystem services?

Answer 27

It reduces pollination, clean water, soil fertility, and disease regulation.

Question 28

What are the two main causes of the current extinction crisis?

Answer 28

Human population growth and resource consumption.

Question 29

How do these causes manifest?

Answer 29

They drive habitat destruction, overexploitation, pollution, invasive spread, and climate change.

Question 30

What is the sixth mass extinction?

Answer 30

The current biodiversity crisis driven by human activities, occurring at unprecedented rates.

Question 31

How are species being lost before they are discovered?

Answer 31

Due to habitat destruction and rapid extinction, many are lost before being described.

Question 32

What are the five threats to species?

Answer 32

Habitat loss, overharvesting, invasive species, pollution, and climate change.

Question 33

How does habitat loss cause extinction?

Answer 33

It destroys or fragments critical habitats, limiting survival and reproduction.

Question 34

How does overharvesting cause extinction?

Answer 34

It removes species faster than they can reproduce.

Question 35

How do invasive species cause extinction?

Answer 35

They outcompete, prey on, or introduce disease to native species.

Question 36

How does pollution cause extinction?

Answer 36

Toxins harm health, reproduction, and ecosystem balance.

Question 37

How does climate change cause extinction?

Answer 37

It alters habitats, migration, food availability, and weather patterns.

Question 38

Which threat is harming the most species?

Answer 38

Habitat loss is the biggest driver of species extinction.

Question 39

Which threat is growing most in importance?

Answer 39

Climate change is increasingly threatening more species over time.

Question 40

What makes a non-native species more likely to be invasive?

Answer 40

r-selected traits, generalist diet, fast reproduction, and lack of predators.

Question 41

What is propagule pressure?

Answer 41

The number and frequency of individuals introduced; higher pressure increases invasion success.

Question 42

Why are islands vulnerable to invasive species?

Answer 42

Island species often lack defenses against predators or competitors.

Question 43

What is the difference between human introduction and natural range expansion?

Answer 43

Human introduction is artificial; natural expansion occurs via ecological processes.

Question 44

What is the goal of restoration ecology?

Answer 44

To repair damaged ecosystems to resemble their original condition or function.

Question 45

What are the key steps in restoration?

Answer 45

Stop harm, restore physical conditions, reintroduce species, monitor and adapt.

Question 46

What is partial restoration?

Answer 46

Restoring some functions and some native species, but not full historical conditions.

Question 47

What does 'no action' strategy in restoration mean?

Answer 47

Allowing natural recovery due to high costs or expected self-repair.

Question 48

Give examples of conservation success stories.

Answer 48

Spix’s macaw, fin whales, Eurasian beavers, and tiger populations have rebounded.

Question 49

What does '30% by 2030' mean?

Answer 49

An international goal to protect 30% of Earth's land and water by 2030.

Question 50

What is sustainable harvest?

Answer 50

Using resources at a rate that allows populations to recover and persist.

Question 51

What is the goal of sustainable harvest?

Answer 51

To balance resource use with long-term population and ecosystem health.

Question 52

What is a logistic growth curve?

Answer 52

S-shaped curve showing population growth that levels off at carrying capacity.

Question 53

What is maximum sustained yield?

Answer 53

The largest yield that can be taken from a population without depleting it.

Question 54

Where is maximum sustained yield on a growth curve?

Answer 54

At half of carrying capacity, where growth rate is highest.

Question 55

What challenges exist in calculating maximum sustained yield?

Answer 55

Uncertainty in population size, dynamics, and environmental variability.

Question 56

What are major causes of habitat loss?

Answer 56

Logging, agriculture, development, roads, damming rivers, draining wetlands, mining, dredging sea floor

Question 57

What is habitat fragmentation?

Answer 57

Loss of connectivity between habitats, restricting movement and dispersal

Question 58

How does habitat loss affect species range?

Answer 58

It restricts the natural range of organisms

Question 59

What movement issues are caused by habitat loss?

Answer 59

Barriers to safe movement; fragmentation limits dispersal

Question 60

How does habitat loss affect invasive species?

Answer 60

Makes it easier for invasive species to spread

Question 61

What kind of habitat is left after loss?

Answer 61

Often sub-optimal habitat

Question 62

What increases due to edge habitat?

Answer 62

Different ecosystem dynamics and microclimates

Question 63

What conflict increases due to habitat loss?

Answer 63

Human–wildlife conflicts