Chapter 1 Learning about life - Dynamic Study Modules

Why is On the Origin of Species by Means of Natural Selection important in biology?

-It presented evolution as a unifying theme that explains common characteristics found throughout diverse species. - It provided a large amount of evidence that supported the evolutionary view that species descended from a common ancestral species. - It proposed a mechanism for descent with modification, called natural selection. In On the Origin of Species by Means of Natural Selection, Charles Darwin used evidence to support the evolutionary view that diverse organisms share common characteristics and that all species evolved from a common ancestor. He also proposed a process or mechanism by which species evolved called natural selection.

Genetic information in DNA is encoded in sequences of how many different molecular "letters".

4. Genetic information in DNA is encoded in sequences of four different molecular "letters". Although bacteria and humans inherit different genes, that information is encoded in an identical chemical language common to all organisms. The chemical names of DNA's four molecular building blocks are abbreviated as A, G, C, and T. A typical gene is hundreds to thousands of chemical letters in length.A gene's meaning to a cell is encoded in its specific sequence of these letters, just as the message of this sentence is encoded in its arrangement of the 26 letters of the English alphabet.

What is required of a scientific study for it to be considered a controlled experiment?

A comparison between at least two groups, one receiving a specific factor of interest and the other not receiving this factor

A family tree showing evolutionary relationships among species is best viewed as ________.

A hypothesis A hypothesis is a proposed explanation for a set of observations. A valid hypothesis must be testable and falsifiable—that is, it must be capable of being demonstrated to be false. A good hypothesis thus immediately leads to predictions that can be tested. Some hypotheses (such as ones involving conditions that can be easily controlled) lend themselves to experiments, or scientific tests. Other hypotheses (such as ones involving aspects of the world that cannot be controlled, such as ecological issues) can be tested by making further observations. In the case of a hypothesis of evolutionary relatedness, further observations can take the form of compared DNA sequences or anatomical measurements.

Which of the following best describes emergent properties?

A property that is not present in the parts but is present in the whole

Which of the following is an example of a conclusion NOT based only on anecdotal evidence?

A single drug trial suggests that in a random sample of 2000 individuals those receiving the drug recovered from flu an average of four days sooner than those receiving only a placebo (a pill not containing the drug). This is a controlled experiment conducted on a relatively large group. A conclusion based on anecdotal evidence would be an assertion based on a single or a few examples that do not support a generalized conclusion—for example, "Today was unusually cold, so global warming must be a hoax!"

What question should be asked in determining whether a source is reliable?

ALL. Is the intent of the source known? Is the information current? Are any experiments described in enough detail that they could be reproduced? Reliable scientific information should additionally be recognized as drawing from known sources of information, having been authored by a reputable expert, and being free of bias.

Which of the following is not a feature of natural selection?

All individuals in a population have equal reproductive success.

Which of the following depicts the correct order of levels in biological organization from broadest to most specific?

Biosphere -> ecosystem -> communities -> populations -> organisms organ and organ system -> tissues -> cells -> organelles -> molecules and atoms Earth's biosphere includes all life and all places where life exists. Ecosystems consist of all living organisms and nonliving components in a particular area. Communities include all living organisms in an ecosystem. Within communities are various populations, or groups of interacting individuals of one species. An organism is an individual living thing composed of organs and organ systems. Tissues are composed of cells and organelles. Organelles are composed of molecules and atoms.

Why are cells considered the smallest unit of life?

Cells are the smallest things that have all the characteristics of life. Molecules and atoms make up organelles and organelles make up cells. Organelles, molecules, and atoms do not demonstrate the properties of life themselves; these collectively emerge at the level of cellular organization.

Which of the following is a false statement?

Energy from the sun is used up by photosynthetic organisms. Producers are photosynthetic organisms that absorb sunlight and convert solar energy to chemical energy stored in sugars and other molecules. The energy is not used up or otherwise destroyed but passed to consumers when they ingest these molecules. Energy flows from producer to consumer and consumer to consumer in an ecosystem. Through this process some energy is lost from the system as heat. Matter, such as carbon or nitrogen, is recycled within an ecosystem.

Which of the following statements best distinguishes hypotheses from theories in science?

Hypotheses are tentative guesses whereas theories are comprehensive explanations supported by evidence.

Which of the following depicts the correct order of the scientific method?

Observation -> question -> hypothesis -> prediction -> experiment The scientific method starts with an observation. Based on this observation, scientists form a question. Next, scientists form hypotheses, which are possible answers to their question. Then they make a prediction about what will happen if their hypothesis is accurate. Finally, they create an experiment to gather evidence that they use to support or reject their hypothesis.

Which of the following is a typical aspect of peer review in the process of scientific publication?

Revision of the written descriptions of experiments, or even the experiments themselves, is often required before a paper is recommended for publication. Before experimental results are published in a scientific journal, the research is evaluated by qualified, impartial, often anonymous experts who were not involved in the study. This process is intended to provide quality control. After a study is published, scientists still often check each other's claims by attempting to confirm observations or repeat experiments.

You walk into a room and flip the light switch but the light in the room does not turn on. You flip it a few more times to make sure it isn't working. You decide the bulb must be dead and replace it. Yet after you put in the new bulb and flip the switch, the light still doesn't turn on. Looking around the room, you notice that several electronic devices are also not working. You go to check the fuse box and find that the breaker needs to be switched on. After doing so, you flip the light switch in your room and this time the light comes on. Which of the following represents a hypothesis from this scenario?

The bulb is dead, so the light will not turn on.

What is the definition of biology?

The study of life

The metabolism of a living organism is its ________.

interconnected network of chemical reactions Within all living organisms, there is a never-ending "chemical square dance" in which molecules swap chemical partners as they receive, convert, and release matter and energy.

A double-blind experiment is one in which ________.

neither the experimenter nor the participants know which individuals are receiving which treatment

Groups of interacting individuals of one species are called a/an ________.

population

In nature, ________ and ________ are related so that ________.

structure; function; function gives insight into structure Structure and function have a relationship in which changing structure often results in an altered function and function will often give insight into structure. The concave shape of a red blood cell provides a large surface area for carrying oxygen and allows for easy movement through blood vessels. In patients with sickle cell anemia, the cells form a crescent shape that can block small blood vessels and deprive tissues of oxygen

In an experiment, an independent variable is ________.

what is being manipulated by the researcher to investigate its effect on some other variable In an experiment, an independent variable is what is being manipulated by the researcher to investigate its effect on some other variable. The other variable is called the dependent variable, or response, and is used to judge the outcome of the experiment. Well-designed experiments often test just one independent variable at a time.