Biology Exam 1

What is the first characteristic of life and an example?

Maintaining Homeostasis: sweating

What is the second characteristic of life and an example?

Energy Processing: photosynthesis

What is the third characteristic of life and an example?

Growth/Development: seed to tree

What is the fourth characteristic of life and an example?

Reproduction: sex

What is the fifth characteristic of life and an example?

Respond to Stimuli: moving hand away when touching something hot

What is the sixth characteristic of life and an example?

Evolutionary Adaptations: long necks of giraffes

What is the seventh characteristic of life and an example?

All Living Things Have Cells: bacteria

What are ribosome-encoding organisms (REOs)?

bacteria, archaea, and eukaryotes

What cell type is the oldest?

prokaryotes (3.7 billion) (no nucleus)

What are the three domains of life?

bacteria, archaea, and eukarya

What are the kingdoms of eukarya?

plantae, fungi, animalia, and protists

What is the classification for organisms?

Dear (domain), King (kingdom), Philip (phylum), Came (class), Over (order), for (family), Good (genus), Spaghetti (species)

What is the process of endosymbiosis?

2 different bacteria are present, 1 engulfs the other, 1 lives inside the other, both benefit, and the internal bacteria are passed through generations

How long ago did eukaryote cells emerge?

1.5 billion years ago (have a nucleus)

How many types eukaryote cells are humans composed of?

260 types & 40 trillion total cells

What is natural selection?

survival of the fittest: population with varied inherited traits, elimination of individuals with trait that = more visible, reproduction of survivors, increased amount of traits that = survival

What is present in many features of cell structure?

unity

How do structure and function work?

structure = function

knowing the structure gives ideas about how it works

knowing the function allows insight into the structure

What is the function of straight cable like fibers?

strength

What is the function of helical shapes?

storage

What is the function of free ends?

breakdown and release of energy

What is qualitative data?

recorded descriptions

What is quantitative data?

numerical measurements (blood pressure, weight, age)

What are the steps of the scientific method?

observation/question, research, hypothesis, experiment, data collection, analysis, conclusion

What is deductive reasoning?

general predictions to specific predictions

What is a theory?

broader than hypothesis, general enough to lead to many hypotheses, and supported by a large body of evidence

What is an element?

substance that can't be broken down (defined by number of protons)

What happens if an atom has incomplete valence shells?

they can share or transfer valence electrons with certain other atoms

What is structural formula?

shows the bonding of atoms (H-OH)

What is an ionic bond?

electrons are transferred from one atom to another (attraction between cation and anion)

What is a cation?

an ion with a positive charge

What is an anion?

an ion with a negative charge

How long ago did Earth form?

4.7 billion years ago

How do hydrogen bonds occur?

between 2 molecules not within

What is the polarity of polar molecules?

weak

What is a buffer?

a solution that resists changes in pH

What do the properties of a carbon-containing molecule depend on?

its carbon skeleton and chemical groups

What does carbon have the ability to form?

proteins, carbs, lipids, nucleic acids, and an inexhaustible variety or organic molecules

carbon + organisms

the diversity of an organism is due to the versatility of carbon

What did Stanley Miller do?

demonstrated that the creation of organic molecules from non-life near volcanoes or hydrothermal vents could have been a stage in the origin of life

What are hydrocarbons?

organic molecules consisting of only carbon and hydrogen (rich in energy) (undergo reactions that release large amounts of energy)

What is dehydration synthesis?

Two monomers bond together through the loss of a water molecule

What is an enzyme?

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction

What is an example of an enzyme?

salivary amylase (breaks down starch to form maltose)

What is blood sugar?

glucose

What is glycogen?

storage form of glucose in animal's liver and muscle cells

What is cellulose?

a substance (made of sugars) that is common in the cell walls of many organisms

What is a symbiotic relationship?

relationship where both organisms benefit

What are lipids?

fats, oils, and steroids that mix poorly with water as they consist mostly of hydrophobic regions (does not include true polymers)

What is hydrogenation?

converting unsaturated fats to saturated fats by adding hydrogen

What does hydrogenating vegetable oils create?

unsaturated fats with trans double bonds which is worse than saturated fats

What is the function of fats?

store energy (adipose cells) and lipid reserves cushion vital organs insulating the body

What is a phospholipid?

2 fatty acids (hydrophobic tails) and a phosphate group attached to glycerol (hydrophilic)

What happens when phospholipids are added to water?

they self assemble into double-layered sheers called bilayers (tails pointing toward interior)

What is cholesterol?

a steroid in animal cell membranes (synthesized in the liver)

What are polypeptides?

polymers built from set of 20 amino acids (range from a few to thousands of amino acids)

What do polypeptides contain?

an amino end (c-terminus) + carboxyl group (n terminus) (r group is the only difference)

What are non-essential amino acids?

amino acids that we can make on our own

What is the monomer of a protein?

amino acid

What is the tertiary structure of a protein?

folding of a polypeptide chain due to interactions between amino acid's r groups

What differentiates hemoglobin from sickle cell hemoglobin?

a change in the sixth amino acid within the sequence (glutamic acid to valine)

What is mad cow disease?

prion causing holes in the brain

What is an example of storage proteins?

casein (milk protein) is a major source of amino acids for baby mammals

ovalbumin (egg white protein) is an amino acid source for the developing embryo

What do receptor proteins do?

response of cell to chemical stimuli

What do contractile and motor proteins do?

movement

What is an example of structural proteins?

keratin - protein of hair, horns, feathers, etc.

silk fibers - used by spiders to make cocoons and web

collagen & elastin - provide fibrous framework in animal connective tissue

What is a gene?

unit of inheritance (consist of DNA)

What are the functions of DNA?

provides directions for its own copying, directs synthesis of messenger RNA, and controls protein synthesis thorough mRNA (gene expression)

What is the sugar in DNA?

deoxyribose (OH, H)

What are nucleotides linked by?

covalent phosphodiester bonds formed by dehydration synthesis

What is the structure of DNA?

two polynucleotides spiraling around an imaginary axis forming a double helix

What are capsid-encoding organisms (CEOs)?

viruses

What is a virus made up of?

protein and nucleic acids (DNA or RNA)

What does natural selection result in?

adaptation of organisms to their environment (bat wings)

What is a control group?

group that does not receive treatment and used to compare experiment with

How do most scientists work?

in teams (graduate and undergraduate), good communication, papers not published until assessed by peers

How do scientists build on the works of others?

check each other's claims by performing similar experiments, if results are not repeated original claim has to be checked, many scientists work on the same questions

What is matter?

anything that takes up space and has mass (made of elements)

Where does an element's mass number come from?

number of protons + neutrons

Where do elements come from?

thermonuclear reactions in the stars

What is an atom?

the smallest unit of matter that still retains properties of an element

What is the chemical behavior of an atom determined by?

distribution of electrons in the outermost electron shells

What are chemical bonds?

attractive forces that hold atoms together

What are the essential elements of life?

CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur)

What are trace elements?

elements necessary for life in small amounts

What are compounds?

atoms of two

or more elements are chemically combined (fixed ratio)

What is a molecular formula?

shows the actual number of atoms (abbreviation) (H2O)

What is a covalent bond?

sharing of electrons between atoms

What is a hydrogen bond?

forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom (intermolecular force) (attraction of partial charges)

What is electronegativity?

atom's attraction for the electrons in a covalent bond (usually oxygen or nitrogen)

What are Van der Waals interactions?

weak attractions that occur when atoms and molecules are very close together and enable the atoms and molecules to stick together

What are molecules?

atoms held together by chemical bonds

What is a polar covalent bond?

unequal sharing of electrons (one atom has higher electronegativity)

What is a non polar covalent bond?

electrons are shared equally (hydrophobic)

What are chemical reactions?

making and breaking of chemical bonds (photosynthesis, combustion, etc.)

products to rectants

may require energy input or release of energy

How were oceans and the atmosphere formed?

collisions with meteorites and volcanic activity (3.8 billion years ago)

What was present in oceans?

CHNOPS

What is cyanobacteria?

photosynthetic bacteria

What does cyanobacteria form?

stromatolites (layered rocks) (3.7 billion years ago)