#Question id: 11382
#XL - R Botany
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: 11384
#XL - R Botany
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: 11392
#XL - S Microbiology
Modes of obtaining nutrients, used by at least some bacteria, include all of the following except
#Question id: 11394
#XL - S Microbiology
Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods would not generally inhibit bacterial growth?
#Question id: 11395
#XL - S Microbiology
Mitochondria are thought to be the descendants of certain alpha -proteobacteria. They are, however, no longer able to lead independent lives because most
genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?
#Question id: 11396
#XL - S Microbiology
Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?