TLS Online TPP Program

#Question id: 12760


Which of the examples below provides appropriate abiotic and biotic factors that might determine the distribution of the species in question?

#Unit 10. Ecological Principles
  1.  The amount of nitrate and phosphate in the soil and wild flower abundance and diversity
  2.  The number of frost-free days and competition between species of introduced grasses and native alpine grasses
  3.  Increased predation and decreased food availability and a prairie dog population after a prairie fire
  4. Available sunlight and increased salinity in the top few meters of the ocean and the abundance and diversity of phytoplankton communities
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TLS Online TPP Program

#Question id: 12162

#Unit 8. Inheritance Biology

Nilsson-Ehle’s cross obtained homozygous varieties of wheat that differed in color, he crossed a variety of wheat that possessed white kernels with a variety that possessed  red kernels and obtained the following results:

The following conclusions are made from the results obtained;

TLS Online TPP Program

#Question id: 12083

#Unit 10. Ecological Principles

In bottom sediments of lakes and streams, organic matter is broken down by heterotrophic microorganisms and ammonia is released. Under aerobic conditions, specialized bacteria convert ammonia to nitrate (nitrification). This nitrate, together with nitrate from other sources, diffuses into the deeper sediments, where it may undergo anaerobic conversion to nitrogen gas (denitrification). These sediments typically contain oligochaete worms that live with their heads buried and their tails waving back and forth in the overlying water. Plastic columns were packed with freshly collected stream sediments and then  covered  with  layers  of  nitrate enriched  water.  A similar  set  of  columns  was packed with sediment that had been sterilized and then covered with either nitrate-enriched water or distilled water. Oligochaete  worms  were  collected  and  acclimated  to  20°(C)Following  acclimation,  worms  were  rinsed  in  distilled water and then added to three sediment columns. The columns were incubated in the dark at 20°C and monitored every three days for changes in the concentration of nitrate in the overlying water. Nitrate concentrations in each of the experimental treatments were plotted against time, as shown in the graph below

It can be concluded from the figure that

TLS Online TPP Program

#Question id: 322

#Unit 1. Molecules and their Interaction Relevant to Biology

A covalent bond is likely to be polar when ________.

TLS Online TPP Program

#Question id: 8848

#Unit 9. Diversity of Life Forms

A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it

TLS Online TPP Program

#Question id: 3041

#Unit 2. Cellular Organization

Which statement about gram-negative bacteria is correct?