Chapter 2 Biology
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
10
Part complete The innermost electron shell of an atom can hold up to _____ electrons
2
How many of the naturally occurring elements are used by your body? Which four are the most abundant in living cells?
25. Oxygen, Carbon, Hydrogen, Nitrogen.
All life on earth is classified by
3 domains. Bacteria, Archaea, and Eukarya
This atom can form up to _____ single covalent bond(s).
4
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
5
Part complete What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
6
Arthropods
90% of all animals are arthropods. segmented bodies, kointed appendages. exoskeleton Crustacians centipedes and milipedes arachnids
Covalent Bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
polar molecule
A molecule containing an uneven distribution of charge due to the presence of polar covalent bonds (bonds having opposite charges on opposite ends). A polar molecule will have a slightly positive pole (end) and a slightly negative pole.
Compound
A substance containing two or more different elements in a fixed ratio; for example, table salt (NaCl) consists of one atom of the element sodium (Na) for every atom of chlorine (Cl).
prokaryotic cell
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
Which of the following helps most to explain why water has a high specific heat?
A water molecule can make 4 hydrogen bonds.
What domain are fish?
All fish are animals, which means they are members of the domain Eukarya and the kingdom Animalia, or the animal kingdom.
Domain Archaea:
Also prokaryotes. Small, and simple .NO Nucleus. archaea are more closely related to us than bacteria. Inhabit extreme environments.
Ion
An atom or molecule that has gained or lost one or more electrons, thus acquiring an electrical charge.
Chemical Bond
An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms.
Radioactive Isotope
An isotope whose nucleus decays spontaneously, giving off particles and energy.
. Most of the prokaryotes known as ______________ live in extreme environments, such as salty lakes.
Archaea
What phylum are insects in?
Arthropoda
Isotopes
Atoms of the same element that have different numbers of neutrons
Most widespread Prokaryote
Bacteria
What phylum are humans in?
Chordates
Taxonomic Hierarchy
Domains, Kingdom, Phylum. The three you need to know.
Organisms with prokaryotic cells are separated into two_________________
Domains. Bacteria and Archaea.
All organisms with eukaryotic cells are grouped in domain
Eukarya.
Domain Eukarya:
Eukaryotes. Larger, more complex cells. Have nucleus and other membrane-encolsed organelles.
Water is sometimes called the "universal solvent." Is that accurate?
For the most part. Water readily dissolves most substances, but not hydrophobic ones.
Ionic Bond
Formed when one or more electrons are transferred from one atom to another
Three kingdoms of Eukarya domain
Fungi Plantae Animalia Protists
Which of these bonds is weakest?
Hydrogen Bonds are weaker than covalent bonds because they do not involvesharing of electrons, and they are weaker than ionic bonds because they involvethe attraction of partial (not full) opposite charges.
Plantae kingdom
Kingdom of multicellular photosynthetic autotrophs that have cell walls containing cellulose
What phylum are mollusks in?
Mollusca
Flatworms
Platyhelminthes Bilateral symmetry. thin bodies aquatic habitats tapeworms- parasites
Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface
Polar groups attract one another.
Why doesn't oil mix with water?
Polar molecules attract one another
What phylum is a sponge in?
Porifera
Domain Bacteria:
Prokaryotes, small and simple, numerous, found everywhere there is life.
Ferns
Sperm must swim through water. seedless vascular plants.
Animalia Phylums
Sponges. Cnidarians Molluscs Flatworms Annelids Roundworms Antrhopods Echinoderms Chordates
Most Common Isotope of Carbon
The isotope carbon-12 (named for its mass number), which has 6 neutrons and 6 protons, makes up about 99% of all naturally occurring carbon. Most of the other 1% of carbon on Earth is the isotope carbon-13, which has 7 neutrons and 6 protons. A third isotope, carbon-14, which has 8 neutrons and 6 protons, occurs in minute quantities.
An uncharged atom
The number of protons is equal to the number of electrons
Which best describes how charges are distributed on a water molecule?
The oxygen end is negative relative to the end with the two hydrogen atoms
How does the pH of the solution on the right compare with that of the solution on the left?
The solution on the right is basic relative to the solution on the left. The solution on the right has a lower concentration of hydrogen ions relative to hydroxide ions than does the solution on the left.
Which of these refers to atoms with the same atomic number but different atomic masses
These atoms are isotopes.
Relative to other substances, water tends to resist changes in temperature. Why?
Water is highly cohesive. Its molecules tend to resist increases in their motion. When water is heated, some of the energy is used to disturb the hydrogen bonds between neighboring molecules.
Dissolving is best described as ...
a mingling of molecules and/or ions. hen sugar dissolves in water, the sugar molecules remain intact but mingle with water molecules. When salt (NaCl) dissolves, its Na+ and Cl- ions separately mingle with water.
Which statement is true of water's tensile strength?
a) It results from hydrogen bonding. (b) It helps to pull water through plants. (c) It involves both cohesion and adhesion.
Which factor is important in making it possible to cool yourself by sweating? Think carefully!
a) Molecules collide with varied angles and speeds. (b) Hydrogen bonds are relatively weak.
Which statement helps to explain why ice is less dense than liquid water?
a) Water molecules make hydrogen bonds at definite angles. (b) Cold molecules move less than warm molecules. The ice lattice has open spaces because of the angles at which hydrogen bonds form. Heat energy can break water molecules free of the lattice so they move into the openings.
Water readily sticks to many other substances, a property called ______.
adhesion
An ionic bond involves ____
an attraction between ions of opposite charge
The open spaces in water's crystal structure make it possible for ...
aquatic life to exist at the North Pole.
Atoms with the same number of protons but with different electrical charges _____.
are different ions
Water striders are common insects that can skip across the surface of ponds and streams. This lifestyle is enabled by water's _____.
cohesion and resulting surface tension
Gymnosperms
conifers. Make cones with seeds.
A(n) _____ bond joins these two oxygen atoms.
double covalent
What phylum are sea stars in?
echinoderm
The tendency of an atom to pull electrons toward itself is referred to as its _____.
electronegativity
Kingdom Fungi includes
eukaryotic organisms that mostly decompose organic wastes and absorb nutrients into their cells.
Bacteria
extremely numerous. Grow on every surface. We eat a lot of bacteria.
Angiosperms
flowering plants. 90% of all living plants are angiosperms. The flowers are the sexual organs. Include fruit growing plants.
Cnidarians
found mostly in the ocean. Radial symmetry. Sea anenomes jellyfish STINGING CELLS
Each water molecule is joined to _____ other water molecules by ____ bonds.
four ... hydrogen
What name is given to the bond between water molecules?
hydrogen
Water has surface tension because ...
hydrogen bonds between surface water molecules resist being stretched.
n a neutral solution the concentration of _____.
hydrogen ions is equal to the concentration of hydroxide ions
In salt, what is the nature of the bond between sodium and chlorine?
ionic
Though you add heat, the temperature of boiling water remains constant because ...
it takes energy to break hydrogen bonds.
Bryophytes
lack vascular tissue. Not very tall. Sperm requires water to regenerate. MOSS NONVASCULAR
A(n) _____ refers to two or more atoms held together by covalent bonds
molecule
Kingdom Animalia consists of
multicellular eukaryotes that obtain their food by ingesting (eating) other organisms.
Kingdom Plantae consists of
multicellular eukaryotes that produce their food by photosynthesi
Roundworms
nematodes cylindrical bodies, unsegmented. tapered ends.
chordates
our phylum. Spinal cords dorsal nerve chords backbone surrounding the nerve cords fish amphibians, reptiles, mammals
The unequal sharing of electrons within a water molecule makes the water molecule _____.
polar
In this molecule, what type of bond is found between the oxygen and hydrogens?
polar covalent
A hydrogen atom with a net __________ is attracted to an oxygen atom with a net _______________.
positive charge , negative charge.
By definition, all atoms of carbon have exactly 6 _______, but the number of _______ varies from one isotope to another.
protons, neutrons.
Annelids
rounded worms with segments.leeches and earthworms.
sponges
simplest animals, only animals that lack tissues, no body symmetrt, mostly marine.
Protists_are a diverse collection of mostly
single-celled eukaryotes, which are sorted into several kingdoms to reflect their evolutionary relationships.
Mollusc
snails slugs clams scallops squids and ocupi
protists
some are multicellular like seaweed. Most are single-celled.
Echinoderms
spiny sharp surfaces. Radial symmetry endoskeleton sea stars sea urchens sand dollars
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
Atomic Number
the number of protons in the nucleus of an atom
Mass Number
the sum of the number of neutrons and protons in an atomic nucleus
Atomic Mass
the weighted average of the masses of the isotopes of an element
Fungi
yeast, mold, mushrooms.
