One group of ecologists has suggested that producers are limited by competition for resources, primary consumers (herbivores) are limited by predation, and secondary consumers (carnivores) are limited by food. If this were true, at which of the following trophic levels would one expect to find substantial evidence for competitive exclusion?

TLS Online TPP Program

#Question id: 28156

#Unit 1. Molecules and their Interaction Relevant to Biology

Some statement are given regarding Platelet-activating factor 

a. It is more water-soluble than most glycerophospholipids and plasmalogens

b. It has a long ether-linked alkyl chain at C-1 of glycerol

c. This released from basophils 

d. It stimulates platelet aggregation and the release of vasoconstrictor serotonin from platelets

Which of the following is true

TLS Online TPP Program

#Question id: 31046

#Unit 4. Cell Communication and Cell Signaling

Ras induces a kinase cascade that includes Raf, MEK, and MAP kinase. Which of the following is a dual-specificity protein kinase?

TLS Online TPP Program

#Question id: 18869

#Unit 13. Methods in Biology

The pace at which light passes through objects in phase contrast microscopy is-

TLS Online TPP Program

#Question id: 10242

#Unit 10. Ecological Principles

Ecologist Robert Macarthur observed that five species of similar warblers coexisted on spruce trees because they

TLS Online TPP Program

#Question id: 9198

#Unit 9. Diversity of Life Forms

Tropical forests are being converted to farm or pasture land at an alarming rate, and one major focus is on the biodiversity and the impact to these ecosystems. What is a direct benefit to humans that helps explain why these forests need to be preserved?