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.
Biodiversity hotspots are defined by the number of endemic species and:
degree of threat.
The chances of a species going extinct are increased when its geographic range is _____________, its local population size is ______________, and its habitat tolerance is ______________.
restricted; small; narrow
What does it mean to say that a species is “endangered”?
That species is in imminent danger of extinction.
What does it mean to say a species is “threatened”?
That species is not in immediate danger of extinction, but it is vulnerable to extinction.
Which description represents an irreversible disturbance?
extinction of the Chinese river dolphin
In the United States, purple loosestrife is a(n):
exotic flowering plant that has caused significant problems for native species.
Which of these is an indirect effect of acid rain?
the loss of calcium and potassium ions from the soil
Global warming is caused mostly by:
the accumulation of greenhouse gases in the earth’s atmosphere.
_______________ is responsible for the greatest loss of tropical forests.
Agriculture
Ozone depletion allows ____________ to reach the earth’s surface.
short-wavelength ultraviolet light
Which of the following statements about species preservation is true?
Saving one species may result in the endangerment of another.
Which maxim is generally true of well-designed biological reserves?
A reserve with diverse habitats is better than a reserve with uniform habitats.
Which of the following statement about plant evolution is true?
The tallest plants are 20 times taller than the tallest animals.
Which of the following is true about monocots?
Monocots are a monophyletic group.
In trees, the epidermis on the stem and roots is replaced by a protective covering of dead:
cork cells.
Which of the following is a vital function that roots perform for a plant?
anchor plants to the ground
The greatest amount of photosynthesis in a plant can be found in:
palisade mesophyll cells.
In what region of the plant do cells divide rapidly by mitosis to provide for growth and expansion?
meristem
Which of the following is true about water and plant leaves?
Leaves must allow some water vapor to escape through stomata in order to transport water from the roots into the leaves.
Which statement about plant growth is true?
Much of what we know about plant nutrition has been derived from experiments with hydroponically grown plants.
Plants do not grow well in pure clay soils because:
the soil packs so tightly it limits the amount of oxygen that can reach roots.
Nitrogen fixation is an energetically costly process. What is the fuel that enables bacteria to split apart nitrogen molecules into a usable form for the plant?
sugars from the plant
In mycorrhizal associations, the fungi benefit the plant by:
helping the plant grow faster and larger.
Cohesion of water molecules in the xylem of a plant is a result of:
hydrogen bonds between the oxygen of one water molecule and a hydrogen of another water molecule.
Many plants have flowers with sweet smells and captivating colors and shapes because:
animals are more likely to transport the plant’s male gametes to female gametes.
Asexual reproduction is advantageous to plants because it:
is energetically efficient and faster than sexual reproduction.
Which of the following is true about a sexually reproducing population?
More energy is required compared to asexual reproduction.
In the life cycle of a non-flowering, non-seed plant (ferns), the process of meiosis produces:
spores
Which structure on a flowering plant is the first to receive the pollen granules?
the stigma
Which of the following is correct about plant gamete production?
The embryo sac arises through mitosis of megaspores.
The embryo sac that forms within the ovule in a plant ovary forms from:
a diploid megaspore mother cell undergoing meiosis.
How do wind- and water-pollinated plants increase their odds of pollination?
They produce tens of millions of pollen grains.
The phrase “double fertilization” in angiosperms is best described by which of the choices below?
Each pollen grain contains two sperm cells and one leads to the fertilization that produces the embryo and the other leads to the fertilization that produces the endosperm.
How does staggered maturation reduce self-fertilization?
Because gametes are ready at different times, the male gamete may be incapable of fertilizing the female gamete.
In flowering plant reproduction, the _______________ develops into the fruit, and the _______________ develops into the seed.
ovary; ovule
Some fruits are designed to be attractive food for animals. Other fruits that rely on animal dispersal are:
sticky or covered with clingy burrs.
Seeds germinate only when levels of oxygen, water, and ________ are optimal.
temperature
Which of the following regarding tree growth is true?
The vascular cambium produces wood.
What happens to meristem cells that are left behind as the top of a plant grows higher?
They become dormant.
Secondary xylem is the main component of:
wood
Unlike animals, which produce each hormone _________________, plants produce hormones _________________.
in a specific part of the body; in many cell types
Which of the following would be most useful to a farmer wanting to significantly increase the size of the radish plants grown on a farm?
gibberellins
When auxin molecules move away from a light source and to the opposite (or more shaded) side of the plant, the result is the plant bends toward the light. Which specific action, stimulated by auxin concentration, results in this bending?
Auxins stimulate greater growth on the shaded side.
The production of the plant hormone ethylene plays a major role in:
leaf death.
In plants, abscisic acid:
maintains seed dormancy and winter dormancy and closes stomata.
Phototropism and gravitropism are both a result of uneven distribution of:
auxins
Which of the following is an important environmental cue that sets and resets a plant’s biological clock?
temperature cycles
What can you conclude from these graphs about the environmental factor(s) that causes flowering in short-day plants?
Plants flower when the length of the night is increasing and falls within a certain range.
