Ch 1: Life

Question 1

Biology

Answer 1

The science of life.

Question 2

Biologist

Answer 2

A scientist who studies life.

Question 3

Observation

Answer 3

The act of perceiving the world around us.

Question 4

Experiment

Answer 4

A disciplined and controlled way of learning about the world and testing hypotheses in an unbiased manner.

Question 5

Hypothesis

Answer 5

A hypothesis, then, is a statement about nature that can be tested by experiments or by new observations

Question 6

Variable

Answer 6

The feature of an experiment that is changed by the experimenter from one treatment to the next.

Question 7

Test Group

Answer 7

The experimental group that is exposed to the variable in an experiment.

Question 8

Control Group

Answer 8

The group that is not exposed to the variable in an experiment.

Question 9

Scientific Inquiry

Answer 9

A deliberate, systematic, and careful way of learning about the natural world.

Question 10

Theory

Answer 10

A deliberate, systematic, careful, and unbiased way of learning about the natural world.

Question 11

How does a scientist turn an observation into a hypothesis and investigate that hypothesis?

Answer 11

Observations form the basis of questions that allow for testable explanations (hypothesis) through the use of experiments.

Question 12

What are the differences among a guess, hypothesis, and theory?

Answer 12

Each is an explanation for observations that differ in the amount of evidence to support that explanation.

Question 13

Mice that live in sand dunes commonly have light tan fur. Develop a hypothesis to explain this coloration.

Answer 13

The color of fur allows the mice to hide from predators by blending in better with the environment.

Question 14

What are the first and second laws of thermodynamics, and how do they apply to living organisms?

Answer 14

The first law of thermodynamics is that matter and energy can be neither created nor destroyed. The second law is that the transformation of energy in a closed/isolated system increases the entropy of that system. Living organisms must use energy to metabolize and maintain homeostasis, some of this energy is lost as heat.

Question 15

What experimental evidence demonstrates that living organisms come from other living organisms?

Answer 15

The experiments done by Francesco Redi and Louis Pasteur.

Question 16

First Law of Thermodynamics

Answer 16

The law of conservation of energy: energy can neither be created nor destroyed—it can only be transformed from one form into another.

Question 17

Second Law of Thermodynamics

Answer 17

The principle that the transformation of energy is associated with an increase in the degree of disorder in the universe.

Question 18

Cell

Answer 18

The simplest self-reproducing entity that can exist as an independent unit of life

Question 19

DNA

Answer 19

A linear polymer of four subunits; the information archive in all organisms.

Question 20

Protein

Answer 20

The key structural and functional molecules that do the work of the cell, providing structural support and catalyzing chemical reactions. The term “protein” is often used as a synonym for “polypeptide.”

Question 21

RNA

Answer 21

A molecule chemically related to DNA that is synthesized by proteins from a DNA template.

Question 22

Central Dogma

Answer 22

Originally, the idea that information flows from nucleic acids to proteins, but not in the opposite direction. More generally, the view that information transfer in a cell usually goes from DNA to RNA to protein.

Question 23

Transcription

Answer 23

The synthesis of RNA from a DNA template.

Question 24

Translation

Answer 24

Synthesis of a polypeptide chain corresponding to the coding sequence present in a molecule of messenger RNA.

Question 25

Gene

Answer 25

The unit of heredity; the stretch of DNA that affects one or more traits in an organism, usually through an encoded protein or noncoding RNA.

Question 26

Replication

Answer 26

The process of copying DNA so genetic information can be passed from cell to cell or from an organism to its progeny.

Question 27

Mutation

Answer 27

Any heritable change in the genetic material, usually a change in the nucleotide sequence of a gene.

Question 28

Plasma Membrane

Answer 28

The membrane that surrounds the cytoplasm of the cell, separating the inside of the cell from the outside of the cell; also called the cell membrane.

Question 29

Nucleus

Answer 29

The compartment of the cell that houses the DNA in chromosomes.

Question 30

Cytoplasm

Answer 30

The contents of the cell other than the nucleus.

Question 31

Prokaryote

Answer 31

An organism whose cell or cells do not have a membrane-bound nucleus; sometimes used to refer collectively to archaeons and bacteria.

Question 32

Eukaryote

Answer 32

An organism whose cells have a true nucleus.

Question 33

Bacteria

Answer 33

One of the three domains of life, consisting of single-celled organisms with a single circular chromosome but no nucleus that divide by binary fission and differ from archaeons in many aspects of their cell and molecular biology.

Question 34

Archaea

Answer 34

One of the three domains of life, consisting of single-celled organisms with a single circular chromosome and no nucleus that divide by binary fission and differ from bacteria in many aspects of their cell and molecular biology.

Question 35

Eukarya

Answer 35

The eukaryotes; one of the three domains of life, in which cells have a true nucleus and divide by mitosis.

Question 36

Metabolism

Answer 36

The chemical reactions occurring within cells that convert molecules into other molecules and transfer energy in living organisms.

Question 37

ATP

Answer 37

The molecule that provides energy in a form that all cells can readily use to perform the work of the cell.

Question 38

What does it mean to say that a cell is life’s functional unit?

Answer 38

A cell is the simplest living entity that can exist independently and all more complex organisms are composed of cells.

Question 39

How does the central dogma help us to understand how mutations in DNA can result in disease?

Answer 39

The central dogma describes the order from DNA to synthesis of proteins. Changes in DNA can result in changes to proteins which can in turn lead to disease.

Question 40

Evolution

Answer 40

Changes in the genetic make-up of populations over time, sometimes resulting in adaptation to the environment and the origin of new species.

Question 41

Natural Selection

Answer 41

The process in which, when there is genetic variation in a population of organisms, the variants best suited for growth and reproduction in a given environment contribute disproportionately to future generations. Of all the evolutionary mechanisms, natural selection is the only one that leads to adaptations.

Question 42

Environmental Variation

Answer 42

Variation among individuals that is due to differences in the environment.

Question 43

Genetic Variation

Answer 43

Differences in genotype among individuals in a population.

Question 44

How does evolution account for both the unity and the diversity of life?

Answer 44

Evolution demonstrates the common ancestry of all living things.

Question 45

How might the heavy-handed use of antibiotics result in the increase of antibiotic-resistant cells in bacterial populations?

Answer 45

Overuse of antibiotics can result in a selection pressure for resistance to the antibiotic.

Question 46

Ecology

Answer 46

The study of how organisms interact with one another and with their physical environment.