BIS 2B EXAM SCRIPT 2025/2026 QUESTIONS WITH
ANSWERS MARKED A+
✔✔Coenocytic - ✔✔hyphae without septa are multinucleate; referring to the condition,
found in some fungal hyphae, of "cells" containing many nuclei but enclosed by a single
plasma membrane, results from nuclear division without cytokinesis
✔✔Pathogen - ✔✔a parasite that causes disease in its host
✔✔Facultative Parasites - ✔✔can attack living organisms but also grow on their own
✔✔Obligate Parasites - ✔✔grow only on host species (usually plants)
✔✔Rhizoids - ✔✔modified hyphae for anchoring to a substrate
✔✔Yeasts - ✔✔single-celled, free-living fungi; not members of a single taxonomic
group, but have evolved multiple times in various groups
✔✔Sessile - ✔✔animals that stay in one place, they must move the environment and
food to themselve
✔✔Motile - ✔✔animals that can move from place to place
✔✔Macronutrients - ✔✔need at least 1 g per kg of dry plant matter (nitrogen,
phosphorus, potassium, sulfur, calcium, magnesium)
✔✔Micronutrients - ✔✔need less than 100 mg/kg (iron, chlorine, manganese, born,
zinc, copper, nickel, molybdenum)
✔✔Nitrogen Cycle - ✔✔bacteria and abiotic processes fix nitrogen has from the
atmosphere, producing ammonia and ammonium ions; nitrifying bacteria oxidize
ammonia to nitrite ions; plants reduce nitrate ions back to ammonium, the form in which
nitrogen is incorporated into proteins; some denitrifying bacteria can reduce nitrate back
to nitrogen has, which returns to the atmosphere
✔✔Fixation (Nitrogen Cycle) - ✔✔of atmospheric N2 and NH3 and NH4+ by abiotic
processes and bacteria, both free living and symbiotic
✔✔Nitrification (Nitrogen Cycle) - ✔✔of these molecules by bacteria to nitrate, which
can be taken up by plant roots
✔✔Nitrate Reduction (Nitrogen Cycle) - ✔✔by plants to NH4+, which can be
incorporated into proteins
,✔✔Denitrification (Nitrogen Cycle) - ✔✔of nitrate by bacteria back to N2, released back
into the atmosphere
✔✔Photoautotrophy - ✔✔an organism that obtains energy from light and carbon from
carbon dioxide
✔✔Symbiosis - ✔✔the living together of individuals of two or more species in a
prolonged intimate relationship
✔✔Vicariant Event - ✔✔the appearance of a physical barrier to organismal dispersal
that splits the range of a species; the event divides the species into two or more
discontinuous populations
✔✔Dispersal - ✔✔if members of a species cross an existing barrier and establish a
new, isolated population, the discontinuous range of the specices is then considered to
be the result of dispersal
✔✔Latitudinal Patterns - ✔✔in the tropics, warm moist air rise, expands and cools,
drops its moisture, and flows poleward; the now cool, dry air warms and retains its
moisture as it descends and reaches Earth's surface at about 30°N and 30°S (creating
deserts)
✔✔Resource Aquisition - ✔✔organisms must obtain (acquire) the matter (chemical
constituents), and energy (also space, mates) necessary for maintenance
(homeostasis), growth (and reproduction)
✔✔Heterotroph - ✔✔an organism that requires pre-formed organic molecules as food;
derive nutrition from other organisms
✔✔Autotroph - ✔✔an organism capable of living exclusively on inorganic materials,
water, and some energy source such as sunlight (photoautotrophs) or chemically
reduced matter (chemolithotrophs)
✔✔Niche - ✔✔the set of physical and biological conditions a species requires to
survive, grow, and reproduce
✔✔Fundamental Niche - ✔✔defined by a species' physiological capabilites
✔✔Realized Niche - ✔✔defined by a species' interactions with other species
✔✔Trade-off - ✔✔the relationship between the benefits of a trait in one context and its
costs in another context
✔✔Principle of Allocation - ✔✔all life functions cannot be simultaneously maximized
, ✔✔Prevailing Winds - ✔✔move water through frictional drag, so air circulation drives
ocean surface water movements (currents) yielding rotating patterns called gyres
✔✔Hadley Cell - ✔✔the low-latitude overturning circulations that have air rising at the
equator and air sinking at roughly 30° latitude; they are responsible for the trade winds
in the Tropics and control low-latitude weather patterns
✔✔Absorpative Heterotrophy - ✔✔organisms (primarily fungi) that feed by secreting
digestive enzymes into the environment to break down large food molecules, then
absorbing the breakdown products
✔✔Xylem - ✔✔in vascular plants, the tissue that conducts water and minerals; xylem
consists, in various plants, of tracheids, vessel elements, fibers, and other highly
specialized cell
✔✔Phloem - ✔✔in vascular plants, the vascular tissue that transports sugars and other
solutes from sources to sinks
✔✔Light Reactions - ✔✔the initial phase of photosynthesis, in which light energy is
converted into chemical energy
✔✔Light-Independent Reaction - ✔✔the energy captured in the light reactions is used
to drive the reduction of CO2 to form carbohydrates
✔✔Primary Growth - ✔✔in plants, growth that is characterized by the lengthening of
roots and shoots and by the proliferation of new roots and shoots through branching
✔✔Secondary Growth - ✔✔in plants, growth that contributes to an increase in girth
✔✔Uniformitarianism (Hutton's Theory) - ✔✔the Earth is/was being continuously
modified (erosion, wind, moving sediments, volcanoes, and earthquakes)—as a
contrast to Catastrophism which held that only infrequent violent disasters could modify
the Earth; past geological processes are natural and similar to those that occur now;
changes in the Earth take place slowly, so the Earth must be very old
✔✔Relative Fitness - ✔✔the number of an organism's (or genotype's) offspring that
survive to reproduce themselves, in comparison to others in the population
✔✔Adaptation - ✔✔characteristic that makes it more likely for an organisms to survive
and reproduce (increase its relative fitness); the process(es) by which such
charactersitics evolve
ANSWERS MARKED A+
✔✔Coenocytic - ✔✔hyphae without septa are multinucleate; referring to the condition,
found in some fungal hyphae, of "cells" containing many nuclei but enclosed by a single
plasma membrane, results from nuclear division without cytokinesis
✔✔Pathogen - ✔✔a parasite that causes disease in its host
✔✔Facultative Parasites - ✔✔can attack living organisms but also grow on their own
✔✔Obligate Parasites - ✔✔grow only on host species (usually plants)
✔✔Rhizoids - ✔✔modified hyphae for anchoring to a substrate
✔✔Yeasts - ✔✔single-celled, free-living fungi; not members of a single taxonomic
group, but have evolved multiple times in various groups
✔✔Sessile - ✔✔animals that stay in one place, they must move the environment and
food to themselve
✔✔Motile - ✔✔animals that can move from place to place
✔✔Macronutrients - ✔✔need at least 1 g per kg of dry plant matter (nitrogen,
phosphorus, potassium, sulfur, calcium, magnesium)
✔✔Micronutrients - ✔✔need less than 100 mg/kg (iron, chlorine, manganese, born,
zinc, copper, nickel, molybdenum)
✔✔Nitrogen Cycle - ✔✔bacteria and abiotic processes fix nitrogen has from the
atmosphere, producing ammonia and ammonium ions; nitrifying bacteria oxidize
ammonia to nitrite ions; plants reduce nitrate ions back to ammonium, the form in which
nitrogen is incorporated into proteins; some denitrifying bacteria can reduce nitrate back
to nitrogen has, which returns to the atmosphere
✔✔Fixation (Nitrogen Cycle) - ✔✔of atmospheric N2 and NH3 and NH4+ by abiotic
processes and bacteria, both free living and symbiotic
✔✔Nitrification (Nitrogen Cycle) - ✔✔of these molecules by bacteria to nitrate, which
can be taken up by plant roots
✔✔Nitrate Reduction (Nitrogen Cycle) - ✔✔by plants to NH4+, which can be
incorporated into proteins
,✔✔Denitrification (Nitrogen Cycle) - ✔✔of nitrate by bacteria back to N2, released back
into the atmosphere
✔✔Photoautotrophy - ✔✔an organism that obtains energy from light and carbon from
carbon dioxide
✔✔Symbiosis - ✔✔the living together of individuals of two or more species in a
prolonged intimate relationship
✔✔Vicariant Event - ✔✔the appearance of a physical barrier to organismal dispersal
that splits the range of a species; the event divides the species into two or more
discontinuous populations
✔✔Dispersal - ✔✔if members of a species cross an existing barrier and establish a
new, isolated population, the discontinuous range of the specices is then considered to
be the result of dispersal
✔✔Latitudinal Patterns - ✔✔in the tropics, warm moist air rise, expands and cools,
drops its moisture, and flows poleward; the now cool, dry air warms and retains its
moisture as it descends and reaches Earth's surface at about 30°N and 30°S (creating
deserts)
✔✔Resource Aquisition - ✔✔organisms must obtain (acquire) the matter (chemical
constituents), and energy (also space, mates) necessary for maintenance
(homeostasis), growth (and reproduction)
✔✔Heterotroph - ✔✔an organism that requires pre-formed organic molecules as food;
derive nutrition from other organisms
✔✔Autotroph - ✔✔an organism capable of living exclusively on inorganic materials,
water, and some energy source such as sunlight (photoautotrophs) or chemically
reduced matter (chemolithotrophs)
✔✔Niche - ✔✔the set of physical and biological conditions a species requires to
survive, grow, and reproduce
✔✔Fundamental Niche - ✔✔defined by a species' physiological capabilites
✔✔Realized Niche - ✔✔defined by a species' interactions with other species
✔✔Trade-off - ✔✔the relationship between the benefits of a trait in one context and its
costs in another context
✔✔Principle of Allocation - ✔✔all life functions cannot be simultaneously maximized
, ✔✔Prevailing Winds - ✔✔move water through frictional drag, so air circulation drives
ocean surface water movements (currents) yielding rotating patterns called gyres
✔✔Hadley Cell - ✔✔the low-latitude overturning circulations that have air rising at the
equator and air sinking at roughly 30° latitude; they are responsible for the trade winds
in the Tropics and control low-latitude weather patterns
✔✔Absorpative Heterotrophy - ✔✔organisms (primarily fungi) that feed by secreting
digestive enzymes into the environment to break down large food molecules, then
absorbing the breakdown products
✔✔Xylem - ✔✔in vascular plants, the tissue that conducts water and minerals; xylem
consists, in various plants, of tracheids, vessel elements, fibers, and other highly
specialized cell
✔✔Phloem - ✔✔in vascular plants, the vascular tissue that transports sugars and other
solutes from sources to sinks
✔✔Light Reactions - ✔✔the initial phase of photosynthesis, in which light energy is
converted into chemical energy
✔✔Light-Independent Reaction - ✔✔the energy captured in the light reactions is used
to drive the reduction of CO2 to form carbohydrates
✔✔Primary Growth - ✔✔in plants, growth that is characterized by the lengthening of
roots and shoots and by the proliferation of new roots and shoots through branching
✔✔Secondary Growth - ✔✔in plants, growth that contributes to an increase in girth
✔✔Uniformitarianism (Hutton's Theory) - ✔✔the Earth is/was being continuously
modified (erosion, wind, moving sediments, volcanoes, and earthquakes)—as a
contrast to Catastrophism which held that only infrequent violent disasters could modify
the Earth; past geological processes are natural and similar to those that occur now;
changes in the Earth take place slowly, so the Earth must be very old
✔✔Relative Fitness - ✔✔the number of an organism's (or genotype's) offspring that
survive to reproduce themselves, in comparison to others in the population
✔✔Adaptation - ✔✔characteristic that makes it more likely for an organisms to survive
and reproduce (increase its relative fitness); the process(es) by which such
charactersitics evolve
