Test 3 (chap 16-20) Flashcards
A population is:
a group of individuals of the same species that live in the same general location and have the potential to interbreed.
Which statement regarding populations is true?
Birth rates, death rates, as well as immigration and emigration rates are all features of a population.
When a population grows in proportion to its current size (e.g., bigger populations grow faster), that population is experiencing ________ growth.
exponential
During logistic growth, the per capita rate of increase:
approaches zero after the population reaches one-half of its carrying capacity.
The lynx-snowshoe hare population dynamic pictured here represents an example of population:
oscillation
The graph shows the population size at which a population can most effectively be utilized for natural resources. What appears to happen when the population reaches its carrying capacity?
The population stays the same size.
Which characteristic is associated with a species that experiences very high mortality rates in the wild?
produces litters of multiple offspring
A trade-off exists between the number of offspring an organism can produce and the amount of care the organism can provide for its offspring. T or F and why
true; this is one of the inherent trade-offs in life history strategies.
Which statement best describes a survivorship curve?
A survivorship curve reflects the relationship of survival rate with age.
Mutations that cause sickness and death after reproduction:
can be passed on to future generations.
When the hazard factor is low, individuals tend to:
age more slowly.
In an experiment that doubled the average life span of fruit flies, the experimental methodology that worked involved:
waiting an extra week to collect eggs, thus ensuring that the parents of those eggs lived longer than average.
The two essential elements of ecosystems are:
the biotic and abiotic environments.
Which phrase best defines a biome?
areas with distinct plant communities and associated with particular climates
Which statement best explains why the temperatures at the equator are warmer than at the North Pole?
The sun shines most directly on the equator and spreads out over a relatively small area.
A rain shadow effect occurs:
when wind from the ocean passes over a coastal mountain to the other side.
A driving force behind ocean currents is:
global wind circulation.
What percentage of sunlight is converted to chemical energy through photosynthesis?
1%
If there were 2,000 units of biomass among the primary producers of a food chain, how much biomass would be expected among the tertiary consumers in that same food chain?
2 units
Which statement is true?
Carbon is a major constituent of phospholipids, ATP, and other energy-storing molecules.
The nitrogen cycle is important biologically because:
nitrogen is a component of amino acids, proteins, and nucleic acids.
Similar to nitrogen, phosphorus is often a limiting resource in soils, which constrains plant growth. Consequently, fertilizers usually contain large amounts of phosphorus.
Runoff into lakes spurs growth of large amounts of algae.
Which of the following statement about a niche is true?
An organism’s realized niche is the subset of the fundamental niche in which the organism actually thrives.
A species of moth with an 11-inch-long tongue feeds on the nectar from a species of orchid with an 11-inch-long nectar tube. In the same way, the orchids depend on the moths for pollination. This relationship is best described by the word(s):
coevolution.
In a New England forest, different species of warbler birds were discovered that feed on things they find in or below the trees. The different bird species, which are nearly identical in most respects, all share the same niche. Yet they all thrive and reproduce successfully. How is this possible?
They feed on different parts of the same trees.
The fire salamander can squirt a nerve toxin from glands on its back to deter predators. This is an example of:
a chemical defense.
Which statement is true about parasites?
They can alter the behavior of their hosts.
In a commensal relationship:
one species benefits while the other is neither benefited nor harmed.
A glacier recedes, leaving behind bare rock. What is the first thing to occur?
Bacteria and fungi establish themselves.
Keystone species:
play an unusually important role in determining the species composition in a habitat.
The total economic value of an ecosystem:
includes all of the ecosystem services, future uses, and non-use values (such as cultural, intrinsic, and aesthetic values) of an ecosystem.
Assessing biodiversity:
is not completely objective.