Intermediate filaments are the only nonpolar fibrous component of the cytoskeleton and are not associated with motor proteins. Intermediate filaments are built from coiled coil dimers that associate in an antiparallel fashion into tetramers and then into protofilaments, 16 of which make up the filament. There are five major classes of intermediate filament proteins. Match the following proteins (Column I) with their class (Column II).

Column I	Column II
A. Lamins	a. Class I
B. Keratins	b. Class II
C. Desmin	c. Class III
D. Neurofilaments	d. Class IV
	e. Class V

Which of the following is correct?

TLS Online TPP Program

#Question id: 13017

#Unit 10. Ecological Principles

Which of the following statements best describes the effect of climate on biome distribution?

TLS Online TPP Program

#Question id: 13018

#Unit 10. Ecological Principles

Generalized global air circulation and precipitation patterns are caused by

TLS Online TPP Program

#Question id: 13019

#Unit 10. Ecological Principles

Air masses formed over the Pacific Ocean are moved by prevailing westerlies where they encounter extensive north- south mountain ranges, such as the Sierra Nevada and the Cascades. Which statement best describes the changes that these air masses undergo?

TLS Online TPP Program

#Question id: 13020

#Unit 10. Ecological Principles

Experts in deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in ?yarding? areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.  This observation best illustrates which of the following principles about factors that limit distribution of organisms?

TLS Online TPP Program

#Question id: 13021

#Unit 10. Ecological Principles

Which marine zone would have the lowest rates of primary productivity (photosynthesis)? 

TLS Online TPP Program

#Question id: 13022

#Unit 10. Ecological Principles

A certain species of pine tree survives only in scattered locations at elevations above 2,800 m in the western United States. To understand why this tree grows only in these specific places an ecologist should