past paper questions (Ecology)

Distinguish between the transfers of energy and inorganic nutrients

Energy - lost at every stage of the trophic level as….

Inorganic nutrients- recycled into the ecosystem via decomposers

Describe how plants affect the amount of carbon dioxide in the atmosphere (4)

• photosynthesis: light energy and inorganic nutrients converted into chemical energy and glucose/carbohydrates

• Respiration of plants releases carbon dioxide

• Consumers eat plants, moving carbon across the food chain

• Dead plants go through fossilization, storing carbon in the form of fossil fuels

• Fossil fuels are them combusted, releasing carbon dioxide, forrest fires also release carbon dioxide

map out the carbon cycle in your head (7)

Compare and contrast between fundamental and realised niche

• They both describe the role occupied by a species

• Fundamental niche is always larger than realised

Dentition of Humans (homosapiens)

• Small teeth - narrow molars and canines present

• Omnivores, feed on plants and cooked meats

Dentition and diet of homo floresiensis

• Relatively big teeth for their size, molars and canines present

• Omnivores, feed on fibrous plants and uncooked meats

Dentition and diet of paranthropus robustus

• Large teeth, very wide molars but insignificant canines

• Herbivorous, feed on tough grass and fibrous plants

Explain the movement of energy and inorganic nutrients in an ecosystem (7)

• sunlight enters the ecosystem as the main source of energy

• Autotrophs perform photosynthesis, converting inorganic nutrients e.g carbon dioxide and light energy into chemical energy and carbohydrates

• Carbon compounds/energy transferred through feeding of heterotrophs e.g consumers

• Energy is lost at each trophic level as heat

• Energy is also lost due to incomplete digestion and incomplete consumption

• Carbon dioxide released back into the atmosphere through respiration of animals, plants and decomposers

• Carbon dioxide also released back through combustion of … and …

• Inorganic nutrients is recycled back into the ecosystem by …

• Energy cannot be recycled

Strangler epiphytes adaptations for sunlight

Climb tree trunks eventually outcompeting them for sunlight

Epiphytes adaptations

Grows on tree trunks eventually outcompeting the trees for sunlight

Shade tolerant shrubs adaptations

Grows on the forrest floor where sunlight is within their range of light tolerance

Lianas adaptations

Grows through different trees using them as support to gather sunlight

Canopy adaptations

Grows wide and tall to outcompete other trees for sunlight