Bio. Test #1

Front 1

there are a total of ___ naturally occurring amino acids in cells.

Back 1

20

Front 2

the oceans help to moderate extremes of temperature in the Earth's climate. What property of water is responsible for this function?

Back 2

high heat capcity

Front 3

the most predominant components of biological membranes are ________

Back 3

lipids

Front 4

the hydrophobic and hydrophilic properties of phospholipids make them particularly well-suited as components of ________

Back 4

cell membranes

Front 5

an atom with no charge must have the same number of _____

Back 5

protons and electrons

Front 6

the characteristic that is shared by all organic molecules is that they _____

Back 6

are made of chains of carbon atoms

Front 7

an ionic bond is defined as one in which _________

Back 7

ions with opposite charges are drawn together

Front 8

a molecule that is termed amphipathic is _____

Back 8

both hydrophilic and hydrophobic

Front 9

which of the following in not one of the elements that make up more than 99% of all matter?
nitrogen
hydrogen
lithium
carbon
oxygen

Back 9

lithium

Front 10

molecules that each consist of a nitrogen-containing aromatic ring compound, a sugar, and a molecule of phosphoric acid are ______

Back 10

nucleotides

Front 11

the most important biological properties of a molecule depend on its interactions with _____

Back 11

water

Front 12

what property of water does a tree take advantage of to transport water from its roots to its leaves?

Back 12

adhesion

Front 13

in water, cohesion creates ______

Back 13

high surface tension

Front 14

molecules that have uneven distributions of electrical charge are said to be ______

Back 14

polar

Front 15

choose the item from the following list that is not one of the four classes of small molecules that make up larger molecules in cells.
sugars
steroid
amino acids
nucleotides
lipids

Back 15

steroids

Front 16

what is protiens corresponding subunit?

Back 16

amino acids

Front 17

what is fats and cholesterols corresponding subunit?

Back 17

lipids

Front 18

what is DNA and RNA's matching subunit?

Back 18

nucleotides

Front 19

what are polysaccharides matching subunits?

Back 19

sugars

Front 20

the form of matter that cannot be broken down into simpler substances is a _____

Back 20

element

Front 21

the positive charge of the nucleus is balanced by negatively charged particles called ______

Back 21

electrons

Front 22

by definition, organic molecules contain the element _________

Back 22

carbon

Front 23

standard, small groupings of atoms on molecules that help to determine its properties are called ______ groups

Back 23

functional

Front 24

______ are the smallest units that still have the properties of an element

Back 24

atoms

Front 25

the __________ in the atomic nucleus are electrically neutral

Back 25

neutrons

Front 26

the breaking apart of a macromolecule to form two or more smaller molecules is a process called ________

Back 26

hydrolysis

Front 27

the ______ in the atomic nucleus are positively charged

Back 27

protons

Front 28

the joining of two smaller molecules to make a macromolecule is a process called ________

Back 28

dehydration condensation

Front 29

two or more atoms that share one or more electrons are said to be held together by _______ chemical bonds

Back 29

covalent

Front 30

______ is the most important life molecule

Back 30

water

Front 31

in water, the ______ phase is more dense than the _____ phase

Back 31

solid
liquid

Front 32

when Robin Warren informed Barry Marshall that many ulcer patients have bacterial infections in their stomachs, Marshall hypothesized that bacteria might cause stomach ulcers. What was the observation that led to this hypothesis?

Back 32

he examined biopsies of many people with stomach problems

Front 33

genetic information is stored in long thin molecules called ____

Back 33

DNA

Front 34

stabilizing the internal environment in a changing external environment

Back 34

homeostasis

Front 35

the number of speicies of organisms that are alive today represent what percentage of the number of species of organsims that have ever lived?

Back 35

about 1 %

Front 36

a scientist performs an experiment and analyzes the results. Such an analysis cannot _____

Back 36

prove the hypothesis is right

Front 37

a set of rules for forming, testing, and eliminating ideas is known as the ______

Back 37

scientific method

Front 38

the process whereby an organism actively adjusts its metabolism to maintain a constant internal environment is called ______

Back 38

homeostasis

Front 39

objects dug up from the ground that contain remains or traces of past life are called _______

Back 39

fossils

Front 40

the process by which species have arisen and changed as they descended from common ancestors is _______

Back 40

evolution

Front 41

the current standard therapy for ulcers is ______

Back 41

antibiotics

Front 42

rough endoplasmic reticulum differs from smooth endoplasmic reticulum in that only the rough has _____

Back 42

ribosomes

Front 43

the cell organelle found in both plant and animals that is surrounded by a double membrane is the ______, also known as the power house

Back 43

mitochondrion

Front 44

an organelle found ony in plants that uses sunlight to make ATP is called the _____

Back 44

chloroplast

Front 45

which structure can be found in both prokaryotes and eukaryotes?

Back 45

plasma membranes and DNA

Front 46

the nucleus of the cell is surrounded by ________

Back 46

a double layer membrane with nuclear pores

Front 47

as cells become larger, they have a proportionately greater internal volume with respect to their total surface area. This most directly limits the cell's ability to _______

Back 47

obtain materials for energy and excrete and excrete waste fast enough to maintain homeostasis

Front 48

membrane protiens are amphipathic, meaning that they _______

Back 48

have both hydroliphic and hydrophobic regions

Front 49

which mechanism of membrane transport requires the expenditure of energy?

Back 49

active transport

Front 50

the plasma membrane consists of ____ layers of ____

Back 50

two
lipids

Front 51

during osmosis _____ moves across the cell membrane

Back 51

water

Front 52

if a red blood cell and a plant cell are placed in distilled water, water will move into the red blood cell until the red blood cell ____ and into the plant cell until the plant cell _____

Back 52

bursts
develops enough turgor to oppose movement of water

Front 53

the cell theory states that ______

Back 53

cells come from other cells
all organisms are composed of one or more cells
cells themselves are alive and are the basic living unit of organization

Front 54

what is considered the main energy currency of living cells?

Back 54

ATP

Front 55

in the absence of oxygen, what process takes place after glycolysis?

Back 55

fermentation

Front 56

the cell organelle that contains enzymes that breaks down large, complex molecules is the _______, also known as the recycler

Back 56

lysosome

Front 57

during rigorous exercise animals burn oxygen faster that it can be supplied and undergo energy conersions without oxygen, what is the by-product of this fermentation process?

Back 57

ethanol

Front 58

allow plant cells to communicate through their cell walls

Back 58

plasmodesmata

Front 59

attach cells to each other so that they cant be pulled apart

Back 59

adhering junction

Front 60

allows communication between cells that are not touching each other

Back 60

membrane receptor

Front 61

seals two cells together so that fluid cannot leak between them

Back 61

tight junction

Front 62

allows chemical signals to pass directly between adjacent animal cells

Back 62

gap junction