C4.1 SL / HL

Question 1

Ecological hierarchy

Answer 1

the synergy of organisms with their environment and leads to the formation of a grouping of organisms

Question 2

population

Answer 2

a group of individuals of the same species living and interbreeding within a given area

Question 3

Transect sampling

Answer 3

a method used to study the distribution and abundance of organisms along a line or pathway

Question 4

Random sampling

Answer 4

used to select a sample that is unbiased. Within each area, every part of the area must have an equal chance of being chosen. Random sampling withquadratsis used to examine differences between contrasting habitats within an habitat

Question 5

sessile organisms

Answer 5

an organism that is anchored to a substrate and cannot move about freely

Question 6

motile organisms

Answer 6

an organism has the capability to move under its own power

Question 7

Quadrats

Answer 7

a frame used in ecology, geography, and biology to isolate a standard unit of area for study of the distribution of an item over a large area

Question 8

Capture-mark-release-recapture

Answer 8

a technique used to estimate the size of a population of a particular species

Question 9

Lincoln Index

Answer 9

a statistical measure used in several fields to estimate the population size of an animal species

Question 10

carrying capacity

Answer 10

the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available

Question 11

Limiting Factors

Answer 11

anything that constrains a population’s size and slows or stops it from growing

Question 12

Positive feedback

Answer 12

output of a system amplifies the system

Question 13

Negative Feedback

Answer 13

responds when conditions change from the ideal or set pointand returns conditions to this set point

Question 14

Density-dependent factors

Answer 14

factors that affect the per capita growth rate of a population differently depending on how dense the population already is

Question 15

Density-independent factors

Answer 15

limiting factors that affect the population of organisms but not restricting them to be at or within a certain number, range, or density

Question 16

Lag phase

Answer 16

the adaptation phase for the organism where they acclimatizes themselves to the new environmental conditions provided. The growth is slow at this stage

Question 17

Exponential phase

Answer 17

where there is a rapid increase in population growth as natality rate exceeds mortality rate

Question 18

Transition phase

Answer 18

where the population growth slows significantly due to limiting factors

Question 19

Plateau phase

Answer 19

Eventually the increasing mortality rate equals the natality rate and population growth becomes static. The population has reached the carrying capacity (κ) of the environment

Question 20

Death Phase

Answer 20

population decreases as death rate is now greater than birth rate; this is usually because food supply is short

Question 21

Logarithmic graphs

Answer 21

graphical representation that employs a logarithmic scale, diverging from the conventional linear scale used in most charts, where values are evenly spaced by creating varying intervals between values

Question 22

model organisms

Answer 22

non-human species that scientists use in the lab to investigate and understand biological processes

Question 23

Duckweed

Answer 23

tiny, free-floating, aquatic green plants commonly found in lentic or slowly moving water bodies, belonging to the family Lemnaceae

Question 24

Community

Answer 24

an interacting group of various species in a common location

Question 25

Intraspecific relationships

Answer 25

Intra-specific interactions are those that occur between individuals of the same species, while interactions that occur between two or more species are called inter-specific interactions

Question 26

Intraspecific competition

Answer 26

a competition between individuals from the same species (cospecifics)

Question 27

herbivory

Answer 27

the consumption of plant material by animals, and herbivores are animals adapted to eat plants

Question 28

predation

Answer 28

a biological interaction where one organism, the predator, kills and eats another organism, its prey

Question 29

parasitism

Answer 29

a relationship between the two living species in which one organism is benefitted at the expense of the other

Question 30

pathogenicity

Answer 30

the ability of an organism, a pathogen, to produce an infectious disease in another organism

Question 31

mutualism

Answer 31

association between organisms of two different species in which each benefits

Question 32

Symbiosis

Answer 32

any of several living arrangements between members of two different species, including mutualism, commensalism, and parasitism

Question 33

self-pollinate

Answer 33

occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant

Question 34

nitrogen fixation

Answer 34

the bacterial process whereby molecular N2 gas is converted to reactive, biologically available forms of nitrogen

Question 35

nitrogen-fixing bacteria

Answer 35

prokaryotic microorganisms that are capable of transforming nitrogen gas from the atmosphere into “fixed nitrogen” compounds, such as ammonia, that are usable by plants

Question 36

Fabaceae

Answer 36

the pea or legume family of plants and are sometimes referred to by their old family name the Leguminosae

Question 37

root nodules

Answer 37

the knob-like structures formed especially on and from roots of leguminous plants, as a result of symbiotic infection by nitrogen-fixing bacteria such as Rhizobium

Question 38

rhizobium

Answer 38

nonspore-forming rod-shaped, motile, aerobic, gram-negative soil bacterium able to colonize in the rhizospheric region of leguminous plants and symbiotically fixes atmospheric nitrogen

Question 39

Mycorrhiza

Answer 39

a mutualistic relationship between fungi and plant roots in most plants

Question 40

hyphae

Answer 40

the feathery filaments that make up multicellular fungi. They release enzymes and absorb nutrients from a food source

Question 41

coral polyps

Answer 41

Corals are made up of tiny individuals called polyps. Each polyp is like a fluid-filled bag with a ring of tentacles surrounding its mouth, and looks like a tiny anemone

Question 42

Zooxanthellae

Answer 42

unicellular, golden-brown algae (dinoflagellates) that live either in the water column as plankton or symbiotically inside the tissue of other organisms

Question 43

Coral bleaching

Answer 43

When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white

Question 44

Endemic species

Answer 44

any species or other taxon whose geographic range or distribution is confined to a single given area

Question 45

Invasive species

Answer 45

non-native species that have colonised a new area to the point of damaging the surrounding environment 

Question 46

cane toads

Answer 46

a large, warty, poisonous amphibian native to South and Central America and considered to be one of the worst invasive species in the world

Question 47

red squirrels

Answer 47

a small rodent with a bushy tail. It is typically a rust-red color with a white or cream-colored underside

Question 48

gray squirrels

Answer 48

 mainly grey fur, but may have red-brown patches, especially around the face and legs. The species has a long, bushy tail 

Question 49

Presence-Absence matrix

Answer 49

 a one represents the presence of species j in cell i, and a zero indicates absence

Question 50

chi-squared test

Answer 50

a statistical test commonly used to determine if there is a significant association between two variables

Question 51

null hypothesis

Answer 51

 a hypothesis that says there is no statistical significance between the two variables

Question 52

Qualitative data

Answer 52

descriptive, expressed in terms of language rather than numerical values

Question 53

critical value

Answer 53

cut-off values that define regions where the test statistic is unlikely to lie

Question 54

Alternative hypothesis

Answer 54

an opposing theory to the null hypothesis. For example, if the null hypothesis predicts something to be true, the alternative hypothesis predicts it to be false

Question 55

Null hypothesis

Answer 55

a hypothesis that says there is no statistical significance between the two variables. It is usually the hypothesis a researcher or experimenter will try to disprove or discredit

Question 56

predator-prey interaction

Answer 56

occurs whenever a predator captures and eats an organism

Question 57

Bottom-up Control

Answer 57

ecological concept where ecosystems are primarily regulated by the availability of nutrients, light, or water, which influence primary production and subsequently impact other ecosystem functions

Question 58

Top-down Control

Answer 58

directional regulation within an ecosystem, where species occupying higher trophic levels exert controlling influences on species at the next lower trophic level

Question 59

Allelopathy

Answer 59

a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms

Question 60

secondary metabolites

Answer 60

the products of metabolism not essential for normal growth, development or reproduction of an organism

Question 61

sinigrin

Answer 61

a natural aliphatic glucosinolate present in plants of the Brassicaceae family

Question 62

penicillin

Answer 62

bactericidal beta-lactam antibiotics that inhibit bacterial cell wall synthesis

Question 63

antibiotic

Answer 63

 medicines that fight bacterial infections in people and animals

Question 64

zone of inhibition

Answer 64

an area of media where bacteria are unable to grow, due to presence of a drug that impedes their growth