B16 - Adaptations, Interdependence, and Competition

Question 1

What is abundance?

Answer 1

A measure of how common or rare a particular type of organism is in a given environment

Question 2

What is a community?

Answer 2

A group of interdependent living organisms in an ecosystem

Question 3

What is distribution?

Answer 3

Where particular types of organisms are found within an environment

Question 4

What is interdependence?

Answer 4

The network of relationships between different organisms within a community, for example each species depends on other species for food, shelter, pollination, seed dispersal etc

Question 5

What is a quadrat?

Answer 5

A sample area used for measuring the abundance and distribution of organisms in the field

Question 6

What is quantitative sampling?

Answer 6

Records the number of organisms rather than just the type

Question 7

What is a sample size?

Answer 7

The size of a sample in an investigation

Question 8

What is a transect?

Answer 8

A measured line or area along which ecological measurements are made

Question 9

What is an ecosystem?

Answer 9

A self-contained interacting community of organisms and the environment in which they live and interact.

Question 10

What is a biotic component of an ecosystem?

Answer 10

A living component of an ecosystem

Question 11

What is an abiotic component of an ecosystem?

Answer 11

A non-living component of the ecosystem

Question 12

What is a producer?

Answer 12

Organisms that produce organic molecules from simple inorganic materials and use them as an energy source. Examples include green plants and algae

Question 13

What is a consumer?

Answer 13

Organisms that feed on the organic matter made by plants, they are Heterotrophs

Question 14

What are Heterotrophs?

Answer 14

Organisms which cannot create their own food from inorganic matter

Question 15

What is a decomposer?

Answer 15

Microorganisms that break down dead or undigested organic material. They are important in nutrient cycling

Question 16

What is a trophic level?

Answer 16

One of the steps in a food chain. Defined by where the organic matter comes from

Question 17

What is a habitat?

Answer 17

The place where an organism lives. It provides the correct environmental conditions (physical, chemical, biological)

Question 18

What is a population?

Answer 18

Group of organisms of the same species living in the same space at the same time

Question 19

What is a niche?

Answer 19

The way of life and role of an organism?

Question 20

What is a species?

Answer 20

A group of organisms with similar characteristics that can potentially interbreed and produce fertile offspring

Question 21

Describe the practical for investigating the total population size in an area:

Answer 21

1) Collect all necessary equipment
2) Measure the length and width of the area you are investigating and calculate the area
3) Split this area into a 1x1m square grid where every square has a unique number
4) Use a random number generator to select a random number which which corresponds to a square
5) Repeat step 4 10 times in order to have a larger and more accurate sample size
6) Place your quadrat at the 10 positions selected and count the number of organisms chosen within the area (if over half the organism is located within the area include it in your count)
7) Find a mean average of daisies per quadrat
8) Divide the average number of daisies by the area of the quadrat
9) Multiply the number calculated by the total area of the area being investigated
10) Record results in appropriate table or graph

Question 22

Describe the practical to discover how the population of an organism is distributed due to biotic and abiotic factors:

Answer 22

1) Collect all necessary equipment
2) Lay a straight tape measure along the area you will be sampling
3) Place the quadrat at the start of your transect
4) Count the number of organisms chosen within the quadrat (if over half the organism is within or under the quadrat include it in your count)
5) Take a measure of the biotic / abiotic factors you are investigating
6) Move the quadrat 1 quadrat length along the transect
7) Repeat steps 4-6 until you have sampled the entire length of the transect
8) Record results in appropriate table or graph

Question 23

What is the primary source of energy for an ecosystem?

Answer 23

the sun

Question 24

What substances are cycled through an ecosystem?

Answer 24

Carbon, Nitrogen, Water

Question 25

What is a stable community?

Answer 25

A community in which all the species and environmental factors are in balance so that population sizes remain fairly constant

Question 26

Name 6 ways in which communities are interdependent:

Answer 26

• Plants produce food by photosynthesis (using energy from the sun)
• Animals eat plants
• Animals pollinate plants
• Animals eat other animals
• Animals use plant and animal materials to build nests and shelter
• Plants need nutrients from animal droppings and decay

Question 27

What 7 abiotic factors affect communities?

Answer 27

• Light Intensity
• Temperature
• Moisture levels
• Soil pH and mineral content
• Wind intensity and direction
• Availability of oxygen
• Availability of carbon dioxide

Question 28

What 4 biotic factors affect communities?

Answer 28

• Availability of food
• New pathogens or parasites
• New predators
• Interspecific competition

Question 29

How does light intensity affect communities?

Answer 29

Light limits photosynthesis, so light intensity also affects the distribution of plants and animals. Some plants are adapted to live in low light level, they may have broader leaves or more chlorophyll, and therefore are more abundant than most other plants that require plenty of light. This may also affect the animal species found in the area that eat certain plants

Question 30

How does temperature affect communities?

Answer 30

Temperature is a limiting factor on photosynthesis and therefore growth in plants. In cold climates plants are small due to little photosynthesis, this in turn affects the numbers of herbivores that can survive and so the number oif carnivores in the community

Question 31

How does moisture levels affect communities?

Answer 31

Many plants cannot survive in waterlogged soils. Their roots are unable to respire, they rot and the plant dies. Other plants, such as pitcher plants, grow best in bogs where the moisture levels are high. If there is no water, there will be little or no life.

Question 32

How does soil pH and mineral content affect communities?

Answer 32

The level of mineral ions, ie nitrate ions, affect the distribution of plants. Carnivorous plants thrive in nutrient poor soils as despite the low nitrate levels, they can trap and digest animal prey. In this way the nitrates are provided when they break down the animal protein. Furthermore, the pH of the soil has a major effect on which plants can grow there and the rate of decay and therefore the release of mineral ions back into the soil. A low (acidic) pH inhibits decay.

Question 33

How does wind intensity and direction affect ecosystems?

Answer 33

In areas with a strong prevailing wind, the shape of the tree and the whole landscapes is affected by the wind. It also means that plants transpire faster

Question 34

How does availability of oxygen affect communities?

Answer 34

The availability of oxygen affects water-living organisms. Some invertebrate can survive in water with low oxygen levels. However, most fish require a high level of dissolved oxygen. The proportion of oxygen in the air varies very little

Question 35

How does the availability of carbon dioxide affect communities?

Answer 35

The level of carbon dioxide acts as a limiting factor for photosynthesis and plant growth. It can also affect the distribution of organisms.

Question 36

How does availability of food affect communities?

Answer 36

when there is plenty of food, organisms will breed successfully. However, when food is in short supply, animals struggle to survive and often do not breed. Offspring may also die if there is not a plentiful supply of food

Question 37

How do pathogens or parasites affect communities?

Answer 37

New pathogens or parasites can damage and even wipe out populations in a community as organisms will have no resistance to the disease

Question 38

How do new predators affect communities?

Answer 38

New predators arriving will mean that organisms have no defences against the new predators and therefore may be quickly wiped out

Question 39

How does interspecific competition affect communities?

Answer 39

interspecific competition may cause new species to outcompete another to the point where numbers become too low for successful breeding