LIFE 220 Chapter 5, 6 + 7
A gradual change in phenotype across an environmental gradient, such as white-tailed deer changing gradually in size from large in the north to small in the south, is referred to as
a cline
Squirrels tend to have larger body sizes at higher latitudes. This could be an example of
a cline.
A gene is
a stretch of DNA coding for a polypeptide chain (sequence of amino acids).
Under which of the following conditions would genetic drift exert the greatest influence?
a very small population
The specific traits of a particular organism enabling it to survive, grow, and reproduce within a given environment are called
adaptations.
The Galápagos Islands are inhabited by 13 species of Darwin's finches that evolved from a single species. This is an example of
adaptive radiation.
In photosynthesis, the net uptake of CO2 by a plant is greatest
at the light saturation point.
The ultimate source of carbon from which life is constructed is derived from
atmospheric carbon dioxide.
The pigment that absorbs light energy (photons) in photosynthesis is
chlorophyll.
Plants can reduce water loss by
closing their stomata
The ingestion of fecal material for further extraction of nutrients is referred to as
coprophagy.
Water flows over gills in the opposite direction of blood flow in a process known as
countercurrent exchange
In tiger salamanders one phenotype is cannibalistic while another is not. Both are stable strategies. Which form of selection is best represented by this scenario?
disruptive
Measurements of bill length in a population of seed-eating birds reveals two distinct groups: small-billed individuals feeding on soft-shelled seeds and large-billed individuals feeding on hard-shelled seeds. This bimodal distribution most likely resulted from
disruptive selection.
Plants using the C4 photosynthetic pathway are unique from C3 and CAM plants in that they
divide photosynthesis between mesophyll and bundle sheath cells.
An allele that completely masks the effect of another allele is considered
dominant.
The regulation of body temperature exclusively from the external environment is referred to as
ectothermy
CAM plants
fix carbon dioxide during the night.
The movement of genes between populations is referred to as
gene flow.
Some species of animals in cold environments lower the freezing point of water in their tissues by increasing solutes in their body fluids, especially
glycerol
Long-distance transport of oxygen to the cells of animals is facilitated by the
heart.
What is the primary original source of genetic variation in a population?
mutation
Animals that feed on both plant and animal tissues are referred to as
omnivores
Which of the following factors does not influence animal heat exchange?
oxygen diffusion rate
The gene pool refers to all of the genetic information within a
population.
Natural selection is visible at the level of
populations
Unlike terrestrial plants, submerged aquatic plants lack
stomata.
Geographic isolates of a particular species that differ from other populations by one or more characteristics are considered to be
subspecies.
An advantage of homeothermy is
that it allows the organism to remain active in a wide range of external temperatures.
A CO2 gradient between the inside and outside of a leaf is maintained during photosynthesis because
the CO2concentration in the mesophyll is constantly decreasing.
The value of photosynthetically active radiation above which no further increase in photosynthesis occurs is referred to as
the light saturation point.
Identical twin raccoons are raised in different environments and yet behave very differently. This is an example of
the norm of reaction.
An animal has a very thin layer of insulation between its body core and surface causing it to have a very high ________.
thermal conductivity
The movement of water from an area of high potential to lower potential is known as
water potential.
Individual beak size of individual finches of the Galápagos Islands
will greatly influence individual survival.
