Exam 1: Studying Life

Because of the similarities shared by many life forms, scientific knowledge gained about one type of organism can often be generalized to other organisms.Biologists studying photosynthesis, for example, have experimented with the Chlorella alga, knowing that they could extend their findings to plants.In this case, photosynthesis in the alga was considered a _______ system.

In the human body you can find a variety of cells, including skin cells, blood cells, bone cells, nerve cells, and muscle cells.You can find the same variety of cells in a frog.Which statement is true about these cells?

After observing that frogs live in clean water but not in polluted water, researchers state that "polluted water kills frogs." This simple statement is an example of

Tsetse flies are parasites that live off fresh blood they obtain by biting their hosts in hot, humid areas in Africa.Their natural hosts are wild pig and bushbuck, a type of antelope, but they have a broad host range.A second parasite, Trypanosoma brucei, is a unicellular organism that spends part of its life cycle in the tsetse fly.This microorganism causes African sleeping sickness in humans and is transmitted into human blood through the bite of a tsetse fly.Humans are increasingly moving into regions where the tsetse fly lives.This has increased deforestation of the natural habitats of pigs and bushbucks, which has caused declines in their populations.Listed below are several possible outcomes of these changes.Evaluate the likelihood of each of the outcomes listed, and select the most likely outcome.

Which is not one of the major steps in the approach that uses a hypothesis and then a prediction?

Scientists postulate that the enclosure of complex proteins and other biological molecules by membranes resulted in the first cells with the ability to

Scientists interested in human biology typically perform experiments with other model systems.Why do scientists use model systems in this way?

Eukaryotic cells differ from prokaryotic cells in that a eukaryotic cell has

A region of Amazon rainforest has been targeted for deforestation so that the land can be used for growing a single crop-a species of palm that will be harvested for its palm oil.What harm could this cause? A biologist might be expected to give the following answer: Because this land will go from harboring many hundreds of thousands of species to having just one species, it is an example of land that will undergo extreme loss of _______.

Gaucher disease is a genetic disorder in which the cells do not produce an enzyme necessary for breaking down fatty substances.Persons afflicted with Gaucher disease experience severe problems, including swelling, bruising, anemia, neurological problems, and bone abnormalities.Some patients die of the disease.Which statement explains why the lack of an enzyme leads to the problems observed in patients with Gaucher disease?

In the scientific method, a hypothesis

Refer to the diagram below showing the steps in the scientific method. Which step in the diagram best illustrates the use of inductive logic?

Which statement about statistical analysis in science is false?

Bacterial cells and human cells share many similar features.Which feature can be used as support for the claim that humans and bacteria have a common origin?

The two membrane-enclosed compartments within cells that are thought to have arisen from prokaryotes engulfing other prokaryotes are mitochondria and _______.

All cells in a complicated multicellular organism

A young child becomes very ill and is taken for medical evaluation.The analysis reveals a genetic disorder, and he is sent home with medication to alleviate his symptoms.Other members of the family are concerned about how the child's illness can affect them.Which statement provides reasonable advice to these family members?

The information needed to produce proteins is contained in

In 1928, British bacteriologist Alexander Fleming made an accidental discovery.He noticed that a fungus had contaminated one of the agar plates he had streaked with a bacterial species to be studied.The fungus prevented the bacteria from growing in the immediate area surrounding the fungus.Upon further investigation, Fleming found that the fungus produced a substance that was the agent responsible for killing the bacteria.He called this substance penicillin.Given this information, which statement best explains why Fleming's discovery is relevant to the general public today?

Plants, fungi, and animals are most closely related to different groups of