bio 208 midterm 2

Question 1

what is Trophic/Trophy/Troph:

Answer 1

Having to do with food,
nourishment (Greek: τροφή – food)

Question 2

what is Autotrophy

Answer 2

(Greek: αὐτός – self)
make their own complex carbohydrates for
nourishment from inorganic C - sources
→ Photosynthesis (energy from light)
→ Chemo synthesis (energy from oxidation)

Question 3

what is Heterotrophy: (Greek: ἕτερος - another)

Answer 3

use organic sources of carbon synthesized by
others to derive energy

Question 4

does prokaryotes draws from variety of energy

Answer 4

yes, it draws its energy from Heterotrophic, photosynthetic, chemosynthetic

Question 4

can Heterotrophy can be found
across all organismal groups

Answer 4

yes. it can be found in fungi, animals, plants, protists, prokaryotes(bacteria, animals)

Question 5

what does protists includes

Answer 5

it mainly includes Heterotrophic and photosynthetic

Question 6

what organismal group are plant mainly in

Answer 6

plants are mainly photosynthetic and a few Heterotrophic

Question 7

what organismal group are fungi and animals

Answer 7

Fungi and animals are all Heterotrophic

Question 8

what are Heterotrophy and their types

Answer 8

Heterotrophy: eats organic material
heterotrophs eat or feed on organic carbon molecules and process these in order to derive
carbon for energy and building tissue
The types are herbivores, carnivores, detritivores

Question 9

what are herbivores

Answer 9

organisms that eat plants.

Question 10

what are carnivores

Answer 10

organisms that eat animals.

Question 11

what are detritivores

Answer 11

organisms that eat dead organic
matter (it used to be alive but is no
longer living)

Question 12

what is the food economic

Answer 12

Heterotroph needs to balances ease of getting food and food quality

Question 13

how does chemosynthetic autotroph- uses organic sources

Answer 13

chemosynthetic autotroph synthesize organic molecules using CO2 as a carbon sources and inorganic molecules as an energy molecules

Question 14

what did the exploation of Galapagons lead

Answer 14

it will changed our view of how a biosphere can be structured

Question 15

what did Sergi Vinogardskii discover

Answer 15

He discovered that some microbes could live off of inorganic matter including sulfur, iron and nitrogen bacteria

Question 16

How do chemosynthetic autotrophs create organic molecules

Answer 16

Chemosynthetic autotrophs use CO₂ as a carbon source and obtain energy from inorganic molecules, such as hydrogen sulfide or ammonium.

Question 17

What discovery did scientists make at the Galápagos rift in 1977

Answer 17

Scientists discovered a deep-sea ecosystem powered by chemosynthesis, where organisms lived around volcanic vents without relying on sunlight.

Question 17

How do sulfur-oxidizing bacteria in deep-sea vents obtain energy?

Answer 17

They use hydrogen sulfide (H₂S) or elemental sulfur as an energy source and convert it into energy to create organic molecules.

Question 18

Where can sulfur-oxidizing chemosynthetic bacteria be found?

Answer 18

They can be found around deep-sea hydrothermal vents, within the tissues of animals like tube worms, and in other hot environments like freshwater thermal vents and surface hot springs.

Question 19

What is the role of nitrifying bacteria in soil?

Answer 19

Nitrifying bacteria, like Nitrosomonas, convert ammonium (NH₄⁺) to nitrite (NO₂⁻) and then to nitrate (NO₃⁻), releasing energy and playing a crucial role in the nitrogen cycle

Question 20

What is the significance of nitrifying bacteria to the biosphere?

Answer 20

They are essential for nitrogen cycling, which is important for plant growth and ecosystem health.

Question 21

What are two types of sulfur-oxidizing bacteria around hydrothermal vents

Answer 21

Free-living bacteria around the vents and bacteria that live symbiotically within invertebrates, such as giant tube worms.

Question 22

What is chemosynthesis, and how is it different from photosynthesis?

Answer 22

Chemosynthesis is the process by which some bacteria create energy and organic molecules using inorganic substances (like H₂S) instead of sunlight, unlike photosynthesis which uses sunlight.

Question 22

Why was the discovery of chemosynthetic ecosystems in the deep sea important?

Answer 22

It changed the understanding that life could exist independently of sunlight, showing that some ecosystems are powered by chemical energy instead.

Question 23

What happens to population density as organism size increases?

Answer 23

Population density declines with increasing organism size

Question 24

What kind of density ranges can be found among organisms in natural environments

Answer 24

There are great ranges in organism densities; for example, bacterial populations can exceed 10⁹ per cubic centimeter, while large mammals and birds can average less than one individual per square kilometer.

Question 25

How do bacterial populations in soil or water compare to large mammals in terms of density

Answer 25

Bacterial populations can exceed 10⁹ per cubic centimeter, whereas large mammals and birds may average less than one individual per square kilometer.

Question 25

What question arises regarding the variation in population density?

Answer 25

What factors produce variation in population density?

Question 25

How are organism densities generally correlated with body size?

Answer 25

Densities of various organisms are highly correlated with body size, with smaller organisms having higher population densities.

Question 25

What is the general trend between population density and body size for animals and plants?

Answer 25

Population densities of animals and plants decrease as body size increases.

Question 26

Why is it common sense that smaller organisms live at higher densities than larger ones?

Answer 26

Smaller animals and plants generally require less space and resources, allowing for higher population densities.

Question 27

What is one benefit of quantifying the relationship between body size and population density?

Answer 27

Quantification translates a general qualitative notion into a more precise quantitative relationship.

Question 28

What example illustrates the benefit of quantifying size and density relationships?

Answer 28

Quantification can show how much population density declines with increased body size

Question 29

What does measuring size-density relationships among various species reveal?

Answer 29

It reveals contrasting size-density relationships for different groups, indicating divergent environmental requirements.

Question 30

Who was one of the first researchers to demonstrate the relationship between body size and population density

Answer 30

A: John Damuth in 1981.

Question 31

What type of animals did John Damuth focus on in his study of body size and population density?

Answer 31

Herbivorous mammals, ranging from small rodents (about 10 g) to large herbivores like rhinoceros (over 10⁶ g).

Question 31

What range did John Damuth find in the population densities of herbivorous mammals?

Answer 31

Population densities ranged from 1 individual per 10 km² to 10,000 individuals per 1 km², covering approximately five orders of magnitude.

Question 32

What was Damuth’s key finding about body size and population density among herbivorous mammals?

Answer 32

Population density decreases with increased body size across 307 species of herbivorous mammals.

Question 33

Who expanded the analysis of body size and population density to a wider variety of animals?

Answer 33

Robert Peters and Karen Wassenberg in 1983.

Question 33

What did the regression line in Damuth’s analysis indicate

Answer 33

It showed the average decrease in population density with increased body size among herbivorous mammals.

Question 34

What additional groups did Peters and Wassenberg include in their analysis of body size and population density?

Answer 34

they included terrestrial invertebrates, aquatic invertebrates, mammals, birds, and poikilothermic vertebrates.

Question 35

What range of animal mass and population density did Peters and Wassenberg’s study cover?

Answer 35

Animal mass ranged from 10⁻¹¹ to about 10².³ kg, and population density varied from less than 1 per km² to nearly 10¹² per km².

Question 36

What common trend did both Damuth and Peters and Wassenberg observe?

Answer 36

Population density decreases with increased body size across different groups of animals

Question 36

What key differences did Peters and Wassenberg find among animal groups in their data?

Answer 36

Aquatic invertebrates generally have higher population densities than terrestrial invertebrates of similar size, and mammals have higher population densities than birds of similar size.

Question 37

Who pointed out the early studies on plant size and population density, and what did he say about it?

Answer 37

James White (1985) noted that plant ecologists have studied the relationship since early in the twentieth century and described it as a fundamental aspect of population biology.

Question 37

What did Peters and Wassenberg suggest regarding the analysis of certain animal groups?

Answer 37

They suggested that aquatic invertebrates and birds may need to be analyzed separately from other animal groups due to unique density patterns.

Question 38

How has the general relationship between animal size and population density been validated

Answer 38

It has held up under careful scrutiny and reanalysis.

Question 39

What similar relationship have plant ecologists found?

Answer 39

Plant ecologists found a similar relationship between plant size and population density.

Question 40

What pattern is observed in plant population density as plant size increases?

Answer 40

Plant population density decreases with increasing plant size

Question 41

How does the size-density relationship in plants differ from that in animals?

Answer 41

In plants, the size-density relationship changes dynamically within a single species over its life cycle, especially due to a process called self-thinning.

Question 41

What is an example of how plant size and density change over a life cycle?

Answer 41

Giant sequoias start as small seedlings living at high densities, and as they grow, their population density declines until mature trees live at low densities.

Question 42

What is “self-thinning” in plant populations?

Answer 42

It is the process where plant density decreases as individual plants grow larger over time.

Question 43

What is the value of the empirical size-density relationship in population studies?

Answer 43

It provides a standard to compare measured densities and helps estimate expected population densities in nature.

Question 44

How can the size-density relationship help in assessing species rarity?

Answer 44

By comparing measured densities with expected densities, researchers can gauge if a species’ density is unusually high, low, or average for its size and taxon.