Ch.5 Study Guide

Question 1

Difference between biotic and abiotic factors

Answer 1

abiotic: nonliving things that affect the organism
biotic: forms of life that the organism interacts with

Question 2

2 examples of biotic and abiotic factors

Answer 2

biotic: plants and bacteria
abiotic: water and sunlight

Question 3

Difference between a habitat and nice

Answer 3

a habitat is where an organism lives where as its niche is its role it plays within that habitat

Question 4

Explain how evolution occurs through natural selection

Answer 4

natural selection is a process that determines which species will reproduce and pass on their genes to the next generation (survival of the fittest), and as a result, evolution occurs due to the changes seen in the genes and characteristics over time

Question 5

An example of evolution/natural selection

Answer 5

peppered moths

Question 6

Define a polyploidy and explain why it’s important in plants

Answer 6

a condition in which the number of sets of chromosomes in plants’ cells are increased— cannot reproduce with closely related species that have different # of sets of chromosomes

Question 7

Explain coevolution and give two examples

Answer 7

concept that two or more species can reciprocally influence evolutionary direction of the other

ex. ) grazing animals and grass species
ex. ) darwin’s orchid and sphinx moth

Question 8

Explain the difference between interspecific competition and intraspecific competition

Answer 8

interspecific competition is competition between organisms of different species where intraspecific competition occurs between organisms of the same species

Question 9

5 types of organism interactions

Answer 9

1. predation
2. competition
3. symbiosis
4. commensalism
5. mutualism

Question 10

Predation

Answer 10

interaction where one animal kills/eats another

Question 11

Competition

Answer 11

interaction where two organisms compete to obtain the same limited resource

Question 12

Symbiosis

Answer 12

close, long lasting, physical relationship between two different species– at least 1 benefits

Question 13

Commensalism

Answer 13

relationship in which one organism benefits and the other isn’t affected
ex.) remoras and sharks

Question 14

Mutualism

Answer 14

relationship in which both organisms benefit

ex.) crocodile and egyptian plover bird

Question 15

Parasitism

Answer 15

relationship in which one organism benefits and the other one is harmed
ex.) fleas

Question 16

Explain the difference between an ecosystem and a community

Answer 16

a community is an assemblage of all interacting species in area

whereas an ecosystem is a define space in which interactions take place between a community with its complex interrelationships, and its physical environment

Question 17

3 major categories of organisms define by ecologists

Answer 17

producers, consumers, and decomposers

Question 18

Producers

Answer 18

organisms that are able to use sources of energy to make organic material

Question 19

Consumers

Answer 19

organisms that require organic matter as a source of food; consume organic matter in order to grow and survive

Question 20

Decomposers

Answer 20

organisms that digest organic molecules in detritus into simpler organic compounds while absorbing soluble nutrients

Question 21

Describe how energy flows through the environment

Answer 21

each step in the flow of energy of an ecosystem is a trophic level; only 10% of energy is transferred

Question 22

Explain the difference between a food chain and a food web

Answer 22

a food chain is the series of organisms involved in the passage of energy from one trophic level to the next who eats who

whereas a food web is intersecting and overlapping food chains (more complexity and diversity)

Question 23

Biogeochemical cycles

Answer 23

Carbon cycle, phosphorus cycle, and nitrogen cycle

Question 24

Carbon cycle

Answer 24

cyclic flow of carbon from the atmosphere to living organisms then back to the atmospheric reservoir

Question 25

Phosphorus cycle

Answer 25

released by erosion then dissolves in water —> plants —> whatever consumes the plants obtains it

decomposers thus recycle phosphorus compounds back into the soil
**ULTIMATE RESOURCE OF PHOSPHORUS ATOMS IS ROCK

Question 26

Nitrogen cycle

Answer 26

cycling of nitrogen atoms between abiotic and biotic ecosystem components

Question 27

Significance of carbon cycle

Answer 27

in order for plants to photosynthesize => grow => animals eat plants

respiration breaks down organic molecules into CO2 and H2O

Question 28

Significance of nitrogen cycle

Answer 28

nitrogen fixing bacteria allows plants to use nitrogen after conversion to ammonia NH3

Question 29

Significance of phosphorus cycle

Answer 29

plants use phosphorus to construct necessary molecules, necessary for animals when consuming other animals, dissolved in water after erosion, decomposers recycle phosphorus back into the soil

Question 30

Explain how humans are impacting nutrient cycles

Answer 30

water withdrawl (groundwater depletion), agriculture and urbanization (increased runoff, flood risks, soil erosion, and decreased infiltration), destruction of wetlands (stops natural water purification process), and pollution of water sources