TLS Online TPP Program

#Question id: 2004


A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Janeʹs cousin Bob), even though Jane has previously given blood for one of Bobʹs needed transfusions. Which of the following might account for this?

#Unit 4. Cell Communication and Cell Signaling
  1. Janeʹs blood type is a match to Bobʹs but her MHC proteins are not.

  2. A blood type match is less stringent than a match required for transplant because blood is more tolerant of change.

  3. For each gene, there is only one blood allele but many tissue alleles.

  4. Janeʹs class II genes are not expressed in bone marrow.

More Questions
TLS Online TPP Program

#Question id: 13124

#Unit 10. Ecological Principles

A recent study of ecological footprints concluded that

TLS Online TPP Program

#Question id: 13125

#Unit 10. Ecological Principles

Which of the following statements is consistent with the principle of competitive exclusion? 

TLS Online TPP Program

#Question id: 13126

#Unit 10. Ecological Principles

Which point in the graph shows -Rate of population growth is highest.


TLS Online TPP Program

#Question id: 13127

#Unit 10. Ecological Principles

Which point in the graph shows -Per capita growth rate is highest


TLS Online TPP Program

#Question id: 13128

#Unit 10. Ecological Principles

Which point in the graph shows -Both population and per capita growth rates are positive but decelerating


TLS Online TPP Program

#Question id: 13129

#Unit 10. Ecological Principles

Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.

Based on Figure 1, which of the following best describes the change in genetic variation over time?