SNS Biology - Ecology Flashcards

Question

Energy Flow Food Chain

Answer 1

1. Producers - autotrophic green plants and chemosynthetic bacteria - use sun and simple raw materials to manufacture carbs, proteins and lipids 2. Primary consumers - consume producers (herbivores) 3. Secondary consumers - consume primary consumers (carnivores) 4. Tertiary consumers - consume secondary consumers (carnivores) 5. Decomposers

Answer 2

Not simple linear chain but intricate collection of interconnected food chains Greater the number of branches and cross-branches, greater the stability

Answer 3

* Each member of food chain utilises some of energy it obtains from food for own metabolism and loses some as heat * Since this means loss of energy at each feeding level, producer at base of pyramid contains greatest amount of energy and smallest amount of available energy is at the top

Answer 4

* Since organisms at upper levels of food chain derive their food energy from organisms at lower levels and since energy is lost from one level to the next, each level can support a successivly smaller biomass

Answer 5

Consumers that are higher in the food chain are usually larger and heavier than those further down Lower organisms have greater total mass, and are greater in number

Answer 6

1. Chemically inert elemental nitrogen is conveted to soluble nitrates which can be used by organisms by lightning and nitrogen fixing bacteria 2. Nitrates are absorbed by plants and used to synthesize nucleic acids and proteins 3. Animals eat the plants and synthesize animal proteins from the plant proteins. Both plants and animals give off wastes 4. Nitrogen locked in dead plants and animals and their wastes is released by the action of bacteria of decay which converts the proteins into ammonia 5. Some ammonia nitrified to nitrites by chemosynthetic bacteria, then to nitrates by nitrifying bacteria. Rest denitrified to release N2

Answer 7

1. Bacteria of Decay - convert nitrogen in wastes and tissues to ammonia 2. Nitrifying - convert ammonia to nitrites and nitrites to usable nitrates 3. Denitrifying - convert ammonia to free nitrogen (N2) 4. Nitrogen fixing - convert free nitrogen to nitrates

Answer 8

1. CO2 enters living world when plants use it to produce glucose via photosynthesis 2. Plant uses glucose to produce carbs, proteins and fats 3. Animals eat plants and use digested nutrients to form carbs, proteins and fats 4. Animals and plants use proteins, fats and carbs produced to fuel respiration which generates CO2 5. Remainder of organic carbon remains locked in bodies of the plants and animals until death - aside from wastes - when decay processes by bacteria return CO2 to the air

Answer 9

Requires: 1. Stable physical environment (abiotic factors) 2. Stable biotic community 3. Constant energy source 4. Living system incorporating energy into organic compounds 5. Cycling of materials between living system and its environment

Answer 10

Orderly process by which one biotic community replaces another until a climax community is established

Answer 11

Community stage in a succession Each is identified by a dominant species

Answer 12

Each community that establishes itself changes the environment making it more favourable or unfavourable for the community that is to succeed it Ultimately a stage arises in which a population alters the environment in such a way that the original conditions that gave rise to that community are recreated - the climax community Final and most stable stage of succession - stable, living part of the ecosystem in which populations exist in balance with each other and the environment

Answer 13

A distinct community which inhabits a particular geographic region

Answer 14

Characterised and named according to climax vegetation of the region - vegetation that becomes dominant and stable after years of evolutionary development - determines climax animal population 1. Desert - small plants and animals. Many plants conserve water actively. Animals live in burrows 2. Grassland - low rainfall, no shelter from carnivorous animals 3. Rain forest - high temp and rainfall, dense vegetation, floor inhabited by saprophytes 4. Temperate deciduous forest - cold winters, warm summers, moderate rainfall 5. Temperate coniferous forest - cold, dry. Much of vegetation has evolved water-conserving adaptations 6. Taiga - less rainfall that temperate forests, occupied by single coniferous tree - spruce. Forest floors contain moss and lichen 7. Tundra - treeless frozen plain. Contains lichens, moss, polar bears, musk oxen, arctic hens 8. Polar region - frozen area, no vegetation, few terrestrial animals

Answer 15

Plants have little controlling influence in communities relative to role in terrestrial biomes 1. Marine 2. Freshwater

Answer 16

1. Intertidal zone - region exposed at low tides which undergoes changes in temp and periods of dryness 2. Littoral zone - region of continental shelf containing ocean area with depths up to 600 ft. Extends several hundred miles from the shore 3. Pelagic - open seas. Divided into photic (extending to depth of 250-600 ft) and aphotic zone

Answer 17

* Rivers, lakes, ponds, marshes * As in marine biomes, factors affecting life in freshwater include temp, transparency, water depth, CO2 and O2 and salt conc

Answer 18

1. Freshwater is hypotonic creating diffusion gradient and diffusion of water into cells. Freshwater organisms have homeostatic mechanisms for removal of excess water 2. In rivers and streams, strong currents exist and survival of fish which have evolved strong muscles and plants with holdfasts is favoured 3. Freshwater biomes, except very large lakes, are affected by variations in climate and weather

SNS Biology - Ecology Flashcards

(42 cards)