biosci 100 BIODIVERSITY mcq prep

the frozen continent 2026 s2 mid sem test

the antarctic krill (euphausia superba): a) cannot overwinter as an adult b) typically grows to 10cm in length c) spawns only on the full moon in march d) shows a large size ratio between it and its food

d) shows a large size ratio between it and its food

krill have a number of strategies to help them survive winter. which of these is false with regards to krill during the winter? a) they down-regulate their metabolism b) they mobilise their energy reserves c) they feed on a variety of food sources d) they enter a cryptobiotic state

d) they enter a cryptobiotic state — this is false; krill do not do this (cryptobiosis is associated with tardigrades, not krill)

the largest terrestrial animal in antarctica is: a) a wingless midge b) a springtail c) a predatory mite d) a diatom e) a herbivorous mite

a) a wingless midge

it is difficult to tell the difference between an immature krill and an adult krill that is over-wintering. this is because: a) the adult krill can down-regulate their metabolism over winter b) they develop similar amounts of fat reserves over winter c) they are omnivorous and grow to the same maximum size d) the over-wintering krill shrinks in size

d) the over-wintering krill shrinks in size

mosses in the antarctic region are different because: a) they are only found near bird colonies b) they produce more energy from photosynthesis at 5°c than 15°c c) they survive in warm places d) they only survive when they are frozen

b) they produce more energy from photosynthesis at 5°c than at 15°c

the southern ocean is: a) a nutrient rich – species poor environment b) a high productivity environment c) a low nutrient – high chlorophyll environment d) a high nutrient – low chlorophyll environment

d) a high nutrient – low chlorophyll environment (hnlc)

which of the following descriptions best describes the maritime antarctic zone? a) antarctic continent and waters out to the antarctic convergence b) the sub-antarctic islands and their surrounding waters c) the west coast of the antarctic peninsula and some offshore islands in that region d) the ross sea and some of the offshore islands in that region

c) the west coast of the antarctic peninsula and some offshore islands in that region

the primary consumers in the southern ocean are: a) dinoflagellates b) herbivorous zooplankton c) carnivorous zooplankton d) phytoplankton

b) herbivorous zooplankton

the main primary producers in the southern ocean are: a) zooplankton b) phytoplankton c) dinoflagellates d) krill

b) phytoplankton

the dominant organism in the decomposition of detritus in the southern ocean is most likely a: a) diatom b) bacterium c) marine mammal d) virus

b) bacterium

the bacteria found within permanent lake ice is derived from: a) benthic invertebrate communities b) benthic microbial mats c) wind-blown sediment d) sub-surface glacial water

c) wind-blown sediment

phytoplankton in the waters around antarctica are consumed mostly by: a) penguins b) krill c) cephalopods (squid) d) diatoms

b) krill

ice cover over lakes: a) prevents wind turbulence b) limits light penetration c) reduces temperature fluctuations d) all of these options are correct

d) all of these options are correct

organisms found in permanent lake ice typically derive from: a) lake sediments b) water run-off c) penguin excrement d) wind-blown sediment

d) wind-blown sediment

one of the major features that can strongly influence inshore benthic (seabed) diversity is: a) the presence of suspension feeders b) phytoplankton productivity c) ice cover d) freshwater runoff

c) ice cover

which of the following statements is not correct? in antarctica, favourable factors for plant growth include: a) low humidity and rapid drainage b) northerly winds and northerly exposure c) wintertime snow cover and slow drainage d) translucent pebbles and high solar radiation

a) low humidity and rapid drainage — this is not favourable (plants need moisture; low humidity + rapid drainage dries the habitat out)

[verify] on the antarctic continent, terrestrial life is mainly found in: a) areas that are now permanently ice- or snow-free b) the ice-free freshwater systems throughout all regions c) the mountain ranges d) areas that are snow- or ice-free for part of the year

a) areas that are now permanently ice- or snow-free (best-supported answer — option d is also plausible phrasing, so check your lecture material)

in antarctica, a community is a collective of organisms: a) with the same populations and same niche b) that always changes each season c) that remains the same year-round d) that changes over time

d) that changes over time

krill eggs are energetically expensive to produce but each egg needs a large, lipid-rich yolk mass because they: a) need to avoid predators during their adult phase of life b) undergo a long period of developmental descent and ascent before feeding independently c) undergo a long period of time as surface zooplankton before moulting into their adult form d) need to store energy to live under the ice during the winter hibernation period

b) undergo a long period of developmental descent and ascent before feeding independently (larvae sink to depth and rely on yolk reserves before they can feed at the surface)

tardigrades can suspend their metabolism by lowering it to <0.01% of its normal rate. what is this physiological condition best known as? a) a thermophobic state b) super-cooling c) desiccation avoidance d) a cryptobiotic state

d) a cryptobiotic state

tullbergia are found in the ______ where they get water from ______. they are unable to disperse due to ______ conditions. a) west antarctic peninsula; rivers; warm b) ross sea; glacial melt; oceanic c) trans-antarctic mountains; ice-melt; extreme d) dry valleys; lakes; dry

d) dry valleys; lakes; dry

where are you most likely to find mosses in the antarctic? a) in the transantarctic mountain range below the snow line b) in areas where it is not always frozen and near a penguin colony c) next to freshwater lake systems that have low levels of cyanobacteria d) in the dry valleys close to areas of high nutrient loads from dust particles

b) in areas where it is not always frozen and near a penguin colony (nutrient enrichment from guano)

what is the limiting micronutrient in the southern ocean? a) nitrogen b) silica c) iron d) cyanobacteria

c) iron — this is the classic hnlc (high nutrient, low chlorophyll) limitation

matching: which description fits "southern ocean ecosystems"? a) have a high chlorophyll, low nutrient environment b) are dominated by cyanobacteria and diatoms and found in lakes c) have antifreeze and can absorb heat d) have a large change in biodiversity when an iceshelf collapses e) are a main contributor to sediment on the southern ocean seabed

d) have a large change in biodiversity when an iceshelf collapses

which description fits "snow algae"? a) have a high chlorophyll, low nutrient environment b) are dominated by cyanobacteria and diatoms and found in lakes c) have antifreeze and can absorb heat d) have a large change in biodiversity when an iceshelf collapses e) are a main contributor to sediment on the southern ocean seabed

c) have antifreeze and can absorb heat — helps them survive and melt the surrounding snow

which description fits "habitats with microbial mats"? a) have a high chlorophyll, low nutrient environment b) are dominated by cyanobacteria and diatoms and found in lakes c) have antifreeze and can absorb heat d) have a large change in biodiversity when an iceshelf collapses e) are a main contributor to sediment on the southern ocean seabed

b) are dominated by cyanobacteria and diatoms and found in lakes

which description fits "phytoplankton"? a) have a high chlorophyll, low nutrient environment b) are dominated by cyanobacteria and diatoms and found in lakes c) have antifreeze and can absorb heat d) have a large change in biodiversity when an iceshelf collapses e) are a main contributor to sediment on the southern ocean seabed

e) are a main contributor to sediment on the southern ocean seabed

which description fits "nearshore benthic communities"? a) have a high chlorophyll, low nutrient environment b) are dominated by cyanobacteria and diatoms and found in lakes c) have antifreeze and can absorb heat d) have a large change in biodiversity when an iceshelf collapses e) are a main contributor to sediment on the southern ocean seabed

e) are a main contributor to sediment on the southern ocean seabed