TLS Online TPP Program

#Question id: 7297


How is the ABC model for floral identity in Arabidopsis similar to the models for homeotic gene function derived from studies in Drosophila?

#Unit 5. Developmental Biology
  1. The key resposnsibility of homeotic genes in both is patterning of dorsal-ventral asymmetry.
  2. In both organisms, one homeotic gene is expressed at the two ends, a second expressed in to domains more central to that of the first and a third expressed more centrally, thus contributing unambiguous identities to all regions of the organism.
  3. In both organisms, homeotic genes interact, so that it is often the combination of genes present that is critical in specifying structure in adult.
  4. The ABC model of Arabidopsis is essentially identical to the Drosophila model for homeotic gene function, in that the Drosophila version of the A gene is abdominal-A, the Drosophila version of the B gene is Abdominal-B, and the Drosophila version of the C gene is Ultrabithorax.

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TLS Online TPP Program

#Question id: 11276

#Unit 10. Ecological Principles

Following statement regarding efficiency at different tropic level for secondary production?

A-high production efficiency individual able to survive at little food

B-production efficiency decrease toward increase tropic level 

C-aquatic herbivore is more efficient grazer than terrestrial grazer

D- Carnivore assimilation efficiency appear to average around 10%

Which above combination are correct?

TLS Online TPP Program

#Question id: 11277

#Unit 10. Ecological Principles

If a species is a keystone predator, then its removal from a community should

(A) Increase population size of the predator’s preferred prey

(B) decrease species diversity in the prey community

(C) decrease productivity of the predator’s preferred prey

(D) increase species diversity in the prey community

TLS Online TPP Program

#Question id: 11278

#Unit 10. Ecological Principles

Which of the following is true with respect to oligotrophic lakes and eutrophic lakes?

A) Oligotrophic lakes are less subject to oxygen depletion.

B) Rates of photosynthesis are lower in eutrophic lakes.

C) Eutrophic lake water contains higher concentrations of nutrients.

D)Sediments in oligotrophic lakes contain larger amounts of decomposable organic matter.

TLS Online TPP Program

#Question id: 11279

#Unit 10. Ecological Principles

Ecosystem A: Actual link 10, number of species 15  

Ecosystem B: Actual link 10, number of species 20   

Connectance of ecosystem A and B

TLS Online TPP Program

#Question id: 11280

#Unit 10. Ecological Principles

Ecosystem services include processes that increase the quality of the abiotic environment. Which of the following processes would fall under this category?

TLS Online TPP Program

#Question id: 11282

#Unit 10. Ecological Principles

Which of the following ecosystems would likely have the largest net primary productivity per hectare and why?