Mastering Biology Chapter 1

Homeostasis is a living organism's

ability to maintain constant internal conditions even when environmental conditions change.

Bacteria are ________________, or single-celled, organisms. In contrast, most fungi, plants, and animals are many-celled, or _______________

unicellular, multicellular

Atoms are to molecules as ______________

tissues are to organs

In which of the three domains do we see examples of organisms that are multicellular?

Eukarya

To what domain do you belong?

Eukarya

How are DNA and genes related?

Genes are segments of DNA that direct the formation of a specific characteristic.

___________ is the study of living things

Biology

Process of mutation

Creates both helpful and harmful genetic variations in a species.

_____________ is the process of generating hypotheses from a well-supported generalization such as a scientific theory.

Deductive reasoning

By definition, "living things, or organisms, all share certain characteristics that, taken together, define life." Which of these is WRONG Organisms grow and reproduce sexually. Organisms, collectively, evolve. Organisms actively maintain organized complexity. Organisms acquire and use materials and energy Organisms sense and respond to stimuli.

Grow and reproduce sexually

What is a characteristic of all life?

Growing

Which of the following statements about viruses is FALSE? People can get colds and flus again because the viruses are constantly mutating. The widespread use of antibiotics has led to resistant strains of viruses. If a virus mutates, the immune system may not recognize the virus. Vaccines are available to prevent several diseases caused by viruses.

The widespread use of antibiotics has led to resistant strains of viruses.

What is a characteristic of life shown by viruses?

They reproduce

Which of the following can be found in bacteria, but not viruses?

a cell membrane

A plant or other organism that can make its own food is known as a(n) ________. An animal or other organism that cannot make its own food is known as a(n) ________.

autotroph, heterotroph

A(n) ________ consists of all the organisms and their nonliving environment within a given area.

ecosystem

Viruses are... not alive because they can only carry out photosynthesis and not cellular respiration. alive because they often contain DNA. not alive because they are not made of cells and require a host cell for reproduction. alive because they mutate and change over time through evolution.

not alive because they are not made of cells and require a host cell for reproduction.

Based on your understanding of the different levels of biological organization, which level from the choices below would be the smallest, most-exclusive grouping? species ecosystem population community biosphere

population

You are a NASA scientist and have discovered an organism in outer space that stores its genetic material in the cytoplasm rather than in a nucleus and cannot perform photosynthesis. Given these characteristics, how might you classify this organism?

prokaryote

A(n) ________ cell lacks a nucleus. A(n) ________ cell has a "true" membrane-enclosed nucleus.

prokaryotic, eukaryotic

Which of the following is a characteristic of life (from a biological perspective) shown by a computer?

Responds to stimuli

How do "natural selection" and "evolution" compare?

Natural selection is the force that drives evolution

Natural Selection

Occurs when there is variation in the population. Favorable traits, for a particular environment, are perpetuated in the population if they provide survival and reproductive value.

Evolution is often described as "survival of the fittest." How would a biologist best measure fitness from the perspective of evolution?

The best measure of fitness is the number of offspring. The more offspring an organism has that survive to reproduce, the more its genes will be represented in the next generation and beyond.

Why is combination drug therapy for HIV/AIDS less likely to lead to resistance than single drug therapy?

The likelihood of one virus spontaneously mutating to be resistant to several different drugs at the same time is extremely small.

Which of the following is an example of a neutral mutation? an individual with Down syndrome, who has inherited an extra chromosome in each cell a child born with blue eyes from two brown-eyed parents lung cancer your skin developing melanoma cancer from extended exposure to the sun without using sunscreen

child with blue eyes

Which of the following is NOT a characteristic of living things? having DNA as a genetic code responding to stimuli exhibiting complex organization being capable of reproduction creating energy

creating energy