Chapter 34 and 37

Which of these is an example of natural selection acting on genetic variation resulting in evolutionary adaptation?

As the African environment became drier and the grasslands more prevalent, arched feet and non-opposable toes, both more effective for walking upright, became more common in hominins (ancestral humans).

Which of the following statements about the phosphorus cycle is false?

Plants release dissolved phosphate ions into the soil.

Humans are primary and secondary consumers.

True

An herbivore is considered a

primary consumer

In a food chain consisting of phytoplankton → zooplankton → fish → fishermen, the fishermen are

tertiary consumer

The level of ecologic organization that incorporates abiotic factors is called a population.

False

Which of the following represents a step in the nitrogen cycle?

Nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia.

Which of the following processes does not occur in ecosystems?

The energy source that powers the system is used by primary consumers to make organic compounds.

A biome - such as a tropical forest or a desert - is a major terrestrial ecosystem covering the Earth.

True

All of Earth that is inhabited by life is called the

biosphere

Organisms that digest molecules in organic material and convert them into inorganic forms are

decomposers

The level of ecologic organization that incorporates abiotic factors is the

ecosystems

The flow of ________ into ecosystems occurs in one direction only, while ________ are recycled within the ecosystem itself.

energy ... chemicals

CO2 flooding into the atmosphere is absorbed by ________ and converted into biomass.

photosynthetic organisms

In a hypothetical food chain consisting of grass, grasshoppers, sparrows, and hawks, the grasshoppers are

primary consumers

Within an ecosystem, a tree is a

producer

One simple thing that you can do to energy invested into agricultural production of food is to eat a diet consisting only of organisms that are

producers

Carbon mainly cycles between the biotic and abiotic worlds through the processes of

respiration and photosynthesis

In an average ecosystem, about how much energy is present in the organisms at a given trophic level compared to the organisms at the next higher trophic level?

ten times as much