IB Biology Final Exam Questions
Correctly Answered.
carbon, hydrogen, oxygen and nitrogen. - CORRECT ANSWER the most frequently occurring chemical
elements in living things are
sulphur, calcium, phosphorus, iron and sodium. - CORRECT ANSWER a variety of trace elements are
needed by living organisms, including
Nitrogen - CORRECT ANSWER Required by proteins. Is included in the amino acid structure. Is Essential
to enzymes required for plant function.
Calcium - CORRECT ANSWER The mineral that strengthens bone and teeth uses calcium. Also important
in nerve synaptic transmission of nerve impulses and muscle contraction. Regulates the cell wall
construction in plants.
Phosphorus - CORRECT ANSWER Part of the phosphate groups in ATP and DNA molecules. In plants it is
needed for cell reproduction and division. It is part of the cell membrane.
Iron - CORRECT ANSWER found in the structure of haemoglobin and essential for the production of red
blood cells. It is involved in the light energy transferring compounds involved in photosynthesis in plants.
Sodium - CORRECT ANSWER Major ion associated with the propagation of a nerve impulse. Can replace
potassium in some plants. In membrane function.
Sulfur - CORRECT ANSWER It is a component of amino acids.
polypeptide - CORRECT ANSWER a peptide containing 10 to more than 100 amino acids
,An atom - CORRECT ANSWER is a single particle of a chemical element. When an atom either gains or
loses an electron it then becomes an ion.
Ions - CORRECT ANSWER are charged,
atoms - CORRECT ANSWER are uncharged.
An Ion - CORRECT ANSWER has either a negative or positive charge depending if it gained or lost an
electron.
Outline the properties of water that are significant to living organisms, including - CORRECT ANSWER
transparency, cohesion, solvent properties and thermal properties.
Water polarity - CORRECT ANSWER uneven sharing of electrons that produces a negative charge near
the oxygen atom and positive charges near each hydrogen atom, high heat capacity, high heat of
evaporation, water is a solvent, water molecules are adhesion and cohesion, ice is more dense then
liquid water
Water is transparent - CORRECT ANSWER which allows light to filter into aquatic environments, and thus
aquatic plants can absorb light and perform photosynthesis. Since the ancestor of all plants originated in
the ocean, the transparency of water has had an immeasurable influence on life as we know it.
Water is also cohesive, - CORRECT ANSWER that is it binds to itself, due to the polarity of the water
molecule. The positive, hydrogen side of the molecule binds to the negative, oxygen side of another
water molecule. This bond is called a hydrogen bond. Water is also adhesive, that is it binds to other
things around it. This property allows for transport of water against gravity in plants. The water adheres
to the xylem tube of plants and is able to be drawn up in long columns up the stem due to its strong
cohesive force
Water's solvent properties - CORRECT ANSWER allows molecules to dissolve in it. This means that water
can transport minerals up the xylem tube and sugars up the phloem tubes in plants. Blood in animals
consists largely of water, allowing the transportation of oxygen, urea and glucose throughout the body.
Water also is the site of metabolic reactions because reactions can occur between dissolved compounds.
,Water's polarity - CORRECT ANSWER also inhibits movement of its molecules. Since all the molecules are
connected, they cannot freely move about as other, non-polar molecules do. Heat, the kinetic energy of
molecules, is thus restricted and so water has a high specific heat (it must absorb large amounts of
energy in order to change states). This means that water can serve as a temperature insulator, and does
so in organisms of all kinds.
Water's high latent heat of vaporization - CORRECT ANSWER is due to strong hydrogen bonds existing
between water molecules.
A large amount of heat is released - CORRECT ANSWER when water in the liquid state vaporizes into the
gaseous state.
'Coolant - CORRECT ANSWER Allows us to perform homeostasis. (We sweat to cool ourselves down).
Additionally, water's high heat of vaporization allows water molecules to absorb large amounts of
energy from the body before evaporating - thus, the sweating individual loses heat.
Transport medium - CORRECT ANSWER Digestion, also important to help transport blood. Phloem in
plants transport nutrients dissolved in water using the cohesive and adhesive properties.
Habitat - CORRECT ANSWER Organisms need water; the ready availability of it is essential in the
choosing of a habitat.
Water's high heat capacity - CORRECT ANSWER (the amount of energy needed to increase the
temperature of 1gm of water by 1 Degrees Celsius)
Water's high heat of vaporization - CORRECT ANSWER (amount of energy absorbed by 1gm of liquid to
be converted to the gaseous form) prevents from plants and animals from overheating and dying.
Coolant - CORRECT ANSWER Lots of energy is required to heat water, thus it has a high specific heat
capacity, as hydrogen bonds are the strongest type of intermolecular forces. Consider sweating; water
acting as a coolant allows it to trap the heat exerted by the body and allows it to evaporate as its energy
is used.
, Transport medium - CORRECT ANSWER Since water is polar, and many molecules are polar, it makes
water a universal solvent, which allows it to dissolve not only many organic substances, but inorganic as
well. It is through the movement of water that substances are carried throughout an organism. Phloem
in plants transport nutrients dissolved in water up the roots to the leaves using its cohesive and
adhesive forces.
Habitat - CORRECT ANSWER Since water is transparent, it allows light to permeate through, allowing
photosynthesis for plants. Also, due to hydrogen bonding, it has high surface tension, providing
organisms such as insects to easily walk on water. Its buoyancy allows some organisms to stay afloat.
Since solid water is less dense than liquid water, it floats above the liquid water, allowing aquatic life
under the ice.
Carbohydrates - CORRECT ANSWER the starches and sugars present in foods, Organic compounds made
of carbon, hydrogen, and oxygen atoms in the proportion of 1:2:1., compounds composed of carbon,
hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom
Lipids - CORRECT ANSWER energy-rich organic compounds, such as fats, oils, and waxes, that are made
of carbon, hydrogen, and oxygen, biochemicals that do not dissolve in water (fats, oils, and waxes) make
up cell membranes, store energy
Proteins - CORRECT ANSWER macromolecules that contain nitrogen as well as carbon, hydrogen, and
oxygen, contains carbon, hydrogen, oxyge, and nitrogen. source of energy. needed by tissue for repair
and growth. made up of 20 amino acids.
organic - CORRECT ANSWER relating or belonging to the class of chemical compounds having a carbon
basis
Organic compounds - CORRECT ANSWER are defined as compounds containing carbon that are found in
living organisms.
Compounds - CORRECT ANSWER are considered inorganic when they contain carbon but are widely
found in the environment (carbon dioxide and hydrogen).
Amino acids - CORRECT ANSWER are molecules containing an amine group, a carboxylic acid group and a
side-chain that varies between different amino acids. The key elements of an amino acid are carbon,
