#Question id: 11382
#Unit 10. Ecological Principles
Ecologist has proposed following explanation to lead biodiversity at tropic.
a) Higher productivity in the tropics allows for more species
b) Environments are more stable and predictable in the tropics, with fairly constant temperatures and rainfall levels year-round
c) Predators and pathogens limit competition in the tropics, which allows more species to coexist
d) High evolutionary speed at tropic than temperate
#Question id: 11383
#Unit 10. Ecological Principles
Following some condition are given for island.
Island P is small and near the mainland;
Island Q is small and far from the mainland;
Island R is large and near the mainland;
Island S is large and far from the mainland
Let NP, NQ, NR and NS denote the number of species on islands P, Q, R and S, respectively. Which of the following is consistent with the theory of island biogeography?
#Question id: 11384
#Unit 10. Ecological Principles
Two islands, P and Q, are similar in habitat and other features. They are 100 and 200 km2 in size respectively, but have the same number of species. Which of the following statements can independently explain this observation?
(i) P is closer to the mainland than Q
(ii) P is further away from the mainland than Q
(iii) P has higher speciation rates than Q
(iv) P has lower speciation rates than Q
#Question id: 11385
#Unit 10. Ecological Principles
Which of the following biomes is correctly paired with the description of its climate?
A) savanna-low temperature, precipitation uniform during the year
B) tundra-long summers, mild winters
C) Taiga-relatively short growing season, Low precipitation
D) temperate grasslands-relatively warm winters, most rainfall in summer
E) tropical forests-nearly constant day length and temperature
#Question id: 11392
#Unit 9. Diversity of Life Forms
Modes of obtaining nutrients, used by at least some bacteria, include all of the following except
#Question id: 11393
#Unit 9. Diversity of Life Forms
Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what are two ʺstrategiesʺ that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?
1. couple them with photosystem II (the photosystem that splits water molecules)
2. package them in membranes that are impermeable to all gases
3. be obligate anaerobes
4. be strict aerobes
5. package these enzymes in specialized cells or compartments that inhibit oxygen entry