Biology 4.1

Question 1

Species

Answer 1

a group of organisms that can potentially interbreed to produce fertile, viable offsprings
- a member of a single species are unable to produce fertile, viable offspring w members of different species
- when two different species do produce offspring by cross-breeding, these hybrids cannot reproduce

Question 2

Population

Answer 2

group of organisms of the same species that are living in the same area at the same time
- organisms that live in different regions are reproductively isolated and unlikely to interbreed, however still classified the same species

Question 3

Community

Answer 3

group of population living together and interacting with each other within a given area

Question 4

habitat

Answer 4

the environment in which species normally lives, or the location of a living organism

Question 5

ecosystem

Answer 5

a community and its abiotic environment

Question 6

ecology

Answer 6

study of the relationship between livign organisms, or between living organisms and their environment

Question 7

Modes of nutrition

Answer 7

Autotrophs - photoautrophs, chemoautotrophs
Heterotrophs - consumers, detrivores, saprotrophs

Question 8

Autotrophs

Answer 8

self feeding
organisms which synthesize organis molecules from inorganic molecules
- photoautrotophs - photosynthesis, using energy form the sun
- chemoautrophs - chemosynthesis, using energy from the ocidation of chemicals

Question 9

Heterotrophs

Answer 9

organisms which obtain organic molecules from other organisms
- other source feeding

Consumers
Detritivores
Saprotrophs

Question 10

Consumers

Answer 10

Heterotrophs
ingest organic matter which is living or recently killed
- herbivores - feed on plant matter
- carnivores - feed on animal matter
- amnivores - diet composed of both plant and meat
- scavengers - feed on dead and decaying carcasses

Question 11

Detritivores

Answer 11

Heterotrophs
ingests non-living organic matter
“detritus” - dead organic matter

Question 12

Saprotrophs

Answer 12

Heterotrophs
“decomposers”
feeds on non-living organic matter by secreting digestive enzymes and absorbing the products

Question 13

Nutrient Cycling

Answer 13

nutrient - material required by an organism, and include elements such as C,N,P
- supply of inorganic nutrients on earth is finite

Cycle:
1. autotrophs obtain inorganic nutrients from the air, water and soil and converts it to organic compounds
2. Heterotrophs ingest these organic compounds and use them for growth and respiration, releasing inorganic by-product (pee/poo)
3. When organisms die, saprotrophs decompose the remains and free inorganic materials into the soil
4. The return of inorganic nutrients to the soil ensures the continual supply of raw materials for autotrophs

Question 14

Mesocosms

Answer 14

small scale of ecosystems
3 components for sustainability in an ecosystem
1. energy availability - light from the sun provides the initial energy source for almost all communities
2. nutrient availability - saprotrophic decomposers ensures the constant recycling of inorganic nutrients within an environment
3. recycling of waste - certain bacteria can detoxify harmful waste byproducts

Question 15

chi squared

Answer 15

if two species are typically found within the same habitat, they show a POSITIVE association
if two species are not typically found within the same habitat, they show a NEGATIVE association

quadrant sampling
- to determine the presence of two species quadrant sampling is used.

1. identify hypothesis
2. construct a table of frequencies
3. apply the chi-squared formula
4. determine the degree of freedom
5. identify p-value - p<0.05 = sig.