C.1 Species and Communities

Question 1

Limiting factors

Answer 1

The factor that is most scare in relation to an organism’s needs.

Question 2

Temperature limiting factor in plants

Answer 2

• Plants can only survive in a range of temperatures to which they are adapted.
• Metabolic pathways are controlled by enzymes that have optimal temperatures.
• High temperatures increase rate of evaporation.

Question 3

Water plant limiting factor

Answer 3

Water availability limits plant growth in most terrestrial ecosystems
- needed to maintain cell turgor
- needed for photosynthesis and respiration

Question 4

Light limiting factor on plants

Answer 4

Light intensity/wavelength limits the plants ability to carry out photosynthesis
- sun or shade

Question 5

Soil pH limiting factor on plants

Answer 5

Most plants only tolerate a narrow soil ph range
- minerals can be bound more strongly in the soil or leeched from the soil at different pHs
- may affect decomposition of organic matter

Question 6

Soil salinity limiting factor of plants

Answer 6

Most plants have a low soil salinity tolerance or can only tolerate a narrow range of salinity

Question 7

Minerals nutrient availability limiting factor of plants

Answer 7

Affects plant fertility, different plants need minerals in different quantities

Question 8

Temperature limiting factor on animals

Answer 8

Temperature must be within a viable range (based on adaptations) for survial
- body size will determine animals ability to conserve heat (large SA:Vol ratio means heat is easily lost or gained)

Question 9

Water limiting factors on animals

Answer 9

Must be avalible in quantities sufficient for the particular species
- need to have osmotic balance
- may be habitat
- transport medium
- place to lay eggs
- source of oxygen
- coolant
- etc

Question 10

Breeding sites limiting factor on animals

Answer 10

Required for the maintenance of the species
- Breed sites provide protection
- Often rich in food or other resources
- Specialized environmental requirements (eg dragonfly nymphs live underwater)

Question 11

Food limiting factors of animals

Answer 11

Food availability is critical in determining the maximum population size
- animals maybe specialized so that they will only consume a particular species
- Seasonal or geographical variation in food directly affects abundance of population

Question 12

Territory limiting factor to animals

Answer 12

Territorial animals are territorial to attract mates, rear young, forage for food, and to avoid predators

Question 13

Example of a limiting factor on plants

Answer 13

Mineral nutrient availability: venus flytraps, traps flys becuase there are not enough nutrients in its own environment
- still use photosynthesis
- a producer and consumer