CHAPTER 1

Question 1

Biology? What does biology help with and understand?

Answer 1

the scientific study of organisms, living and fossil

the goal -> is discovering and understanding the diversity and complex processes that make up life

Question 2

common features shared among all life forms?

Answer 2

-exist in populations that evolve over time
-made of a common set of chemical compounds
-made up of cells
-use molecules from the environment to synthesize
-extract energy from the environment and use it to do work
-regulate their internal environment
-contain genetic information that enables them to develop, function, and reproduce
-use a universal genetic code to build proteins

Question 3

what do our striking similarities in chemical compounds say about life?

Answer 3

it leads us to the conclusion that all life has a common ancestry

Question 4

how long ago did earth form? how long did it take for life to evolve?

Answer 4

-earth formed 4.6 to 4.5 billion years ago
-life took about 600 million years to first form

Question 5

what are the several elements essential for life to evolve?

Answer 5

-nucleic acids : that reproduce themselves and serve as templates for protein synthesis

-enclosure of biological molecules : by membranes (keep things in and out) made of fatty acids (non-soluble), sillier to liposomes

Question 6

define liposome.

Answer 6

a spherical structure contained by a membrane of phospholipids
-can be used to deliver drugs to cells

Question 7

define prokaryotes. what are the two main groups?

Answer 7

-unicellular organisms that do not have nucleic or other membrane-enclosed organelles
-two groups are bacteria and archaea (found in extreme environments)

Question 8

define eukaryotes. define nucleus

Answer 8

-eukaryotes: organisms whose cells contain their genetic material inside a nucleus, and have membrane-enclosed organelles
-nucleus: contains genetic information

Question 9

what is photosynthesis? when was it introduced in the earth? what were the first photo synthesizers? what does this mean for earth?

Answer 9

-photosynthesis-> metabolic processes carried out by plants and some microorganisms where sunlight is transformed to chemical energy; providing food for other organisms
-intoruced to earth 2.5 billion years ago
-photosynthetic cells similar to cyanobacteria(prokaryotic cells capable of photosynthesis) were the first photo synthesizers
-this means oxygen is introduced to the earths atmosphere

Question 10

what evolved from the abundance of oxygen?

Answer 10

-organisms had an anaerobic metabolism which is occurring without the use of oxygen

-once oxygen was more abundant; organisms involved to have an aerobic metabolism which is occurring in the presence of oxygen

Question 11

what did accumulating oxygen lead to?

Answer 11

-this lead to the formation of the ozone (O3) layer –> absorbs damaging UV radiation

-once there was enough ozone (500 million years ago) organisms were able to leave the protection of the water and move onto land

Question 12

define cell specialization. what did it allow?

Answer 12

-cell specialization: is a division of labor such that different cell types become responsible for different functions
-which allowed multicellular organism to get larger, more efficient, and adapt to environments

Question 13

define tissues

Answer 13

a group of similar cells organized into a functional unit

Question 14

define organs

Answer 14

organs are composed of different tissues integrated to perform a distinct function
EX: heart, liver, brain, etc

Question 15

define organ systems

Answer 15

an interrelated and integrated group of tissues and organs that work together in a physiological function

Question 16

where do organisms acquire nutrients? what does the break down of nutrient molecules do? what types of work?

Answer 16

-organisms get nutrients from their environment
-the break down of nutrient molecules supplies raw material (to build organism’s structures) and energy to do work
-work: movement; biochemical work; electrical work in the nervous system

Question 17

how do organisms regulate their internal environment?

Answer 17

-self-regulation to maintain a constant internal environment (self-regulation through homeostasis)

Question 18

define homeostasis

Answer 18

the maintenance of a steady state, such as a constant temperature, by means of physiological or behavioral feedback responses

Question 19

define sensory mechanisms? what is it used for?

Answer 19

-Regulation requires information about the internal and external environments, so organisms have sensory mechanisms.

Question 20

define effector mechanisms? what is it used for?

Answer 20

-Effector mechanisms alter conditions.

Question 21

define signaling mechanisms? what is it used for?

Answer 21

-Signaling mechanisms integrate information and enable communication between sensors and effectors.

Question 22

what is the external hierarchy of the biological world?

Answer 22

Biosphere -> global ecosystem; entire portion of earth inhabited by life
Ecosystem -> a biological communist & its physical environment
Communities -> all organisms inhabiting & interacting in a particular area
Populations -> same species living & interacting with each other same place and time
Organisms -> individuals
Organ & Organ System -> structure of two or more tissues with specific functions; group of organs working together
Tissues -> group of similar cells with specific functions
Cells -> smallest unit of “life”
Organelles -> membrane-enclosed structure with a specialized function
Molecules -> group of two or more atoms held together by covalent bonds
Atoms -> smallest unit of matter

Question 23

define biomes

Answer 23

the major ecosystems that cover board geographic areas with distinctive physical features and communities are known as biomes

Question 24

define biosphere

Answer 24

all of the biomes on our plant make up the biosphere

Question 25

who showed that inherited traits exist in discrete units?

Answer 25

Gregor Mendel

Question 26

define genes. define genome.

Answer 26

-Gregor Mendel showed that inherited traits exist in discrete units which were later termed genes
-genome: sum total of all the DNA molecules in an organism

Question 27

define DNA. define nucleotides. define mutations.

Answer 27

-DNA: consists of long sequences of nucleotides
-nucleotides: sequences determine that amino acid sequences in proteins
-mutations (change in nucleotide sequences) but occasionally lead to new adaptations

Question 28

define population

Answer 28

-population: groups of individuals of the same species that interbreed

Question 29

define evolution. define natural selection. who proposed it?

Answer 29

-evolution: results in change in the genetic makeup of populations over time
-natural selection: a process in which individuals with certain inherited traits are more likely to survive & reproduce that are individuals that do not have those traits
-Charles Drawin & Alfred Russel Wallace proposed it but separately

Question 30

define artificial selection

Answer 30

Selective breeding of organisms, commonly practiced by animal and plant breeders, to increase the frequency of a favored trait from one generation to the next.

Question 31

define adaptation

Answer 31

process that makes an organism better able to survive and reproduce that leads to evolution

Question 32

define genomics. define bioinformatics.

Answer 32

-genomics: The scientific study of entire sets of genes and their interactions
-bioinformatics: The use of computer programs and mathematical approaches to analyze complex biological data, such as DNA sequences.

Question 33

define binomial. define genus.

Answer 33

-binomial: A taxonomic naming system in which each species is given two names (a genus name followed by a species name).
-genus: A group of related, similar species recognized by taxonomists with a distinct name used in binomial nomenclature.

Question 34

define phylogenetic tree. know how to use one.

Answer 34

-A graphic representation of the lines of descent among organisms or their genes.

Question 35

what are the 5 steps of the scientific approach?

Answer 35

-make observations
-ask questions
-form hypotheses
-make predictions
-test the predictions

Question 36

define inductive logic and deductive logic

Answer 36

-inductive logic: uses observations or facts to develop a tentative answer or hypothesis
-deductive logic: is used to predict what facts would also have to be true to be compatible with the hypothesis

Question 37

define hypothesis. define null hypothesis.

Answer 37

-hypothesis: A tentative answer to a question, from which testable predictions can be generated. (educated guess)
-null hypothesis: the premise that any differences observed in an experiment are simply the result of random differences that arise from drawing two finite samples from the same population. (a presumption of status quo or no change.)

Question 38

what are the two types of experiments? define them.

Answer 38

-controlled experiments: manipulate one factor while holding other variables constant
-comparative experiments: compare data gathered from population that differ in multiple ways

Question 39

define model systems

Answer 39

-using one type of organism to understand others

Question 40

what are characteristics that distinguish science and non-science?

Answer 40

-scientific hypotheses must be testable and the potential of being rejected
-science depends on evidence that comes from reproducible and quantifiable observations