Biology test

Question 1

various types of organisms that live in the same suburban backyard. these organisms together make up…?

Answer 1

a community

Question 2

Biotic factors are the living components of an ecosystem. They are sorted into three groups:…?

Answer 2

producers or autotrophs
consumers or heterotrophs
decomposers or detritivores.

Question 3

a location where primary succession cannot occur?

Answer 3

a forest that has been destroyed by fire

Question 4

homo erectus and homo sapiens belong to the…?

Answer 4

same genus but different species

Question 5

genetic diversity is important as it ensures that a species can…? (3)

Answer 5

avoid inbreeding with members of the same species
resist disease
survive when the conditions of its environment are changed

Question 6

adaptions? (3)

Answer 6

behavioural
structural
physiological

Question 7

natural source of carbon dioxide emissions? (2)

Answer 7

plant/animal respiration

volcanic combustion

Question 8

consequence of increasing carbon dioxide concentrations in the atmosphere?

Answer 8

enhanced green house effect

Question 9

difference between habitat destruction and habitat fragmentation?

Answer 9

habitat destruction is the complete removal and deconstruction of the habitat/ecosystem that organisms occupy. habitat fragmentation is when the natural ecosystem is broken up into isolated patches.

Question 10

why polar bear is keystone species?

Answer 10

it applies to the control of the population of seals, whales, walrus, reindeer, rodents, seabirds, fish, and vegetation in its ecosystem. this prevents those population sizes from increasing to unsustainable levels which could disrupt the food web.

Question 11

community?

Answer 11

the populations of different species interacting in the same place at the same time.

Question 12

how can re-establishment of climax community occur after a fire?
climax community= An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.

Answer 12

there is existing soil after disturbance, colonising plant species can quickly grow.

Question 13

trophic level of ecosystem is removed? what is this called?

Answer 13

trophic cascade

Question 14

consequences of ecosystem without sea otters? (keystone species)

Answer 14

the sea urchin population will increase. there is increased predation of kelp (producers) to the point where it is completely removed from the ecosystem. this results in the collapse of other trophic levels and chains that rely on kelp for energy production.

Question 15

define structural adaption?

Answer 15

physical characteristics that an organism possesses which increase its chance of survival and reproduction.

Question 16

define behavioural adaptions?

Answer 16

behaviours exhibited by an organism that increases its chance of survival and reproduction.

Question 17

define physiological adaptions?

Answer 17

metabolic processes that an organism possesses which increase its chance of survival and reproduction.

Question 18

needs fulfilled by adaptions that enable an animal to survive in its environment? (3)

Answer 18

hair in ears and eyelashes - prevent debris from getting into ears and eyes.
wings - to fly
hormone & electrochemical signals to generate the desired response

Question 19

Abiotic factors?

Answer 19

non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.
such as:
Sunlight
Soil
Water
Atmospheric and Dissolved Gases
Temperature
Fire

Question 20

population?

Answer 20

The term “population” surrounds a group of organisms of a single species that can interbreed and live at the same time in the same environment.

Question 21

species?

Answer 21

A species is often defined as a group of organisms that can reproduce naturally with one another and create fertile offspring.

Question 22

producer?

Answer 22

Producers are organisms that make their own food; they are also known as autotrophs. They get energy from chemicals or the sun, and with the help of water, convert that energy into useable energy in the form of sugar, or food. The most common example of a producer are plants.

Question 23

consumers?

Answer 23

Consumers are organisms that need to eat to obtain energy.

Question 24

decomposer?

Answer 24

They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.

Question 25

the trophic levels?

Answer 25

1: Plants and algae make their own food and are called producers.
2: Herbivores eat plants and are called primary consumers.
3: Carnivores that eat herbivores are called secondary consumers.
4: Carnivores that eat other carnivores are called tertiary consumers.

Question 26

arrows in food chain

Answer 26

show the direction in which energy and nutrients flow

Question 27

10% rule

Answer 27

On average, only about 10 percent of energy stored as biomass in a trophic level is passed from one level to the next.

Question 28

why start with producer?

Answer 28

because some organism has to be able to produce energy from its environment to get the chain/web started.

Question 29

keys points of natural selection.

Answer 29

Variation, Inheritance, Selection, Time and Adaptation.

Question 30

how an original (ancestral) population may develop into 2 different species.

Answer 30

These changes might occur by natural selection or by random chance (i.e., genetic drift), and in both cases result in reproductive isolation.

Question 30

how an original (ancestral) population may develop into 2 different species.

Answer 30

These changes might occur by natural selection or by random chance (i.e., genetic drift), and in both cases result in reproductive isolation.