LE Midterm
Which statement best describes the plasma membrane of a living plant cell?
It selectively regulates the passage of substances into and out of the cell.
The cells of some organisms contain both chloroplasts and mitochondria. Which statement describes what would happen in these cells if they were moved from a light environment to a dark one?
The amount of oxygen present would decrease and the amount of carbon dioxide would increase.
If the ribosomes of a cell were destroyed, what effect would this most likely have on the cell?
The cell would be unable to synthesize proteins.
Which statement is most likely correct regarding soil bacteria that inhabit the polar regions of Earth?
They contain enzymes that function at low temperatures.
deforestation most likely results in
a decrease of biodiversity in the area
Sweating is a process that helps cool the body during strenuous exercise. This is an example of
a feedback mechanism
Which group would most likely have the greatest survival success during a long period of environmental changes?
a large population of red ants living in a forest
increased human population growth usually results in
a need for stronger environmental protection laws
the pattern of numbers in a genetic information molecule is
a sequence of paired bases
A change in the external or internal environment of an organism is known as
a stimulus
what does abiotic and biotic mean?
abiotic is nonliving and biotic is a living thing
Since cyanide is a poison that limits a cell's ability to manufacture ATP, a cell containing cyanide is least likely to carry on the process of
active transport
To produce trypsin inhibitors, plants must synthesize these proteins from
amino acids
Experiments revealed the following information about a certain molecule: It can be broken down into amino acids. It can break down proteins into amino acids. It is found in high concentrations in the small intestine of humans. This molecule is most likely
an enzyme
An overpopulation of deer in a certain area will most likely lead to
an increase in competition between the deer
The tall wetland plant, purple loosestrife, was brought from Europe to the United States in the early 1800s as a garden plant. The plant's growth is now so widespread across the United States that it is crowding out a number of native plants. This situation is an example of
an unintended effect of adding a species to an ecosystem
Chittenango Falls State Park in central New York State is the only known habitat for an endangered species of aquatic snail. Contamination of its water supply and reduction of its habitat have threatened the future of this snail. Which step could be taken to protect this species of snail?
banning human activities that have caused the snail problem
A community is trying to decide on the location for a new shopping center. Two possible locations have been proposed, with each location having some benefits and some problems. The proper approach to deciding the best location would be to
compare the trade-offs of building at either location
In an ecosystem, nutrients would be recycled if they were transferred directly from herbivores to carnivores to
decomposers
A volcanic eruption destroyed a forest, covering the soil with volcanic ash. For many years, only small plants could grow. Slowly, soil formed in which shrubs and trees could grow. These changes are an example of
ecological succession
what is ATP
energy (ATP IS ENERGY!)
which statement best describes the flow of energy and the movement of chemical compounds in an ecosystem
energy is transferred from organism to organism in a food chain and chemical compounds are recycled
Which chemicals are used to cut DNA into fragments for a gel electrophoresis procedure?
enzymes
vultures, which are classified as scavengers, are an important part of the ecosystem because they
feed on dead animals, which aids in recycling of environmental materials
Which process can produce new inheritable characteristics within a multicellular species?
gene alterations in gametes
Some honeybees have been able to survive the changes in their environment and reproduce. This is most likely due to
genetic diversity in the bees
car exhaust has been blamed for increasing the amount of carbon dioxide in the air. some scientists believe this additional carbon dioxide in the air may cause
global warming
Enzyme molecules normally interact with substrate molecules. Some medicines work by blocking enzyme activity in pathogens. These medicines are effective because they
have a shape that fits into the enzyme
Organisms that obtain and ingest organic molecules for their nutrition are classified as
heterotrophs
a species in a changing environment would have the best chance of survival as a result of mutation has a
high adaptive value and occurs in its gametes
Which long-term change could directly cause the other three?
increasing human population
Which situation has had the most negative effect on the ecosystems of Earth?
increasing human population
which human activity will have a negative effect on society?
increasing world population
Some farmers currently grow genetically engineered crops. An argument against the use of this technology is that
its long term effects on humans are still being investigated
A fruit fly is classified as a consumer rather than as a producer because it is unable to
make its own food
Excretion is best described as the removal of
metabolic wastes from a cell
Which two factors provide the genetic basis for variation within a species?
mutations and sexual reproduction
variations within a species are most likely the result of
mutations and sexual reproduction
Which sequence correctly represents the arrangement of structures containing genetic material, from the largest to the smallest size?
nucleus → chromosome → gene
Which sequence represents structures organized from most complex to least complex?
oak tree → leaf → guard cell → chloroplast
what will most likely occur if two different plant species compete for the same requirements in an ecosystem
one species may be eliminated from the ecosystem
one season there was a shortage of produces in a food web. as a result the numbers of deer and wolves decreases. the reason that the deer and wolf population decreased is because
organisms in this food web are interdependant
A human activity that could significantly decrease the amount of carbon dioxide in the air is
preserving and expanding forest habitats that shelter wildlife
a function of cell membranes in humans is the
recognition of certain chemicals
environmentalists are hoping to protect endangered organisms by calling for a reduction in the use of pesticides, because loss of these organisms would
reduce biodiversity in various ecosystems
When Charles Darwin traveled to the Galapagos Islands, he observed 14 distinct varieties of finches on the islands. Darwin also observed that each finch variety ate a different type of food and lived in a slightly different habitat from the other finches. Darwin concluded that the finches all shared a common ancestor but had developed different beak structures. The different beak structures mentioned in the last sentence were most likely influenced by
selection for favorable variation
the theory of evolution states that
species change over time, sometimes developing into new species
Which technique enabled scientists in the 1800's to identify cell organelles?
staining
abiotic factors that characterize a forest ecosystem include
temperature and amount of water
The dashed line on the graph represents
the carrying capacity
one reason as to why people should be careful about their actions on environment is
the depletion of finite resources cannot be reversed
Deforestation of areas considered to be rich sources of genetic material could limit future agricultural and medical advances due to
the loss of biodiversity
what is the advantage of each bird species having a different niche
there is less competition for food
Scientists hypothesize that cabbage, broccoli, cauliflower, and radishes developed along a common evolutionary pathway. Which observation would best support this hypothesis?
these plants have similar proteins
which statement about evolutionary pathways is most accurate
two organisms on the same branch are more closely related to each other than to those on distant branches
organisms that eat cows obtain less energy from the cows than the cows obtain from plants they eat because the cows
use their energy for their own metabolism
The differences seen in the beaks of the four species of finches are most likely the result of
variation and natural selection
A farmer wanted to rid his apple trees of a particular leaf-eating insect. He sprayed his trees with an insecticide that killed 98% of the insects. The survival of 2% of this population of insects is most likely due to
variations that resulted from sexual reproduction
many vaccinations stimulate the immune system by exposing it to
weakened microbes
when is extinction of a species most likely to occur
when the environment changes & the species has a lack of reproducing
Vaccinations usually stimulate the body to produce more of
white blood cells & antibodies
