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Biology 202 Exam1
First exam
34
Biology
Undergraduate 2
04/22/2010

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Term
T-lymphocytes are responsible for
Definition
cell-mediated immunity
Term
Clonal Expansion of B cells
Definition
Clonal selection only occurs after a B cell with a receptor for a specific antigen encounters that antigen and after further interaction with a helper T cell
Term
Helper T Cells
Definition
-Cytokines secreted by helper T cells are necessary for B cells to complete the clonal expansion process
-are a type of white blood cell
-cells sometimes help to activate killer T cells
Term
If a persons bone marrow were destroyed by radiation, what cells could not be produced
Definition
-B cells
-T cells
-Red blood cells
-Neutrophils (a type of phagocytic white blood cell)
Term
Where do CD4+ and CD8+ T lymphocytes mature?
Definition
Thymus
Term
What leads to a definitive, positive diagnosis of AIDS in an HIV infected patient
Definition
Helper T cell counts drop below 200 cells/mm3 of blood
Term
Helper T cell
Definition
when a CD4+ cell becomes activated
Term
Phase I
Definition
this phase of HIV infection is accompanied by a detectable level of HIV antibodies in the bloodstream, and symptoms including fever, chills, and swollen lymph nodes.
Term
In order to become activated, a CD8+ T lymphocyte must recognize a specific antigen that is presented to it on this type of protein
Definition
MHC-I
Term
Antibodies play a significant role in the destruction of specific pathogen. In what way do they promote this process?
Definition
Antibodies promote production of killer T cells, which go on to attack cells infected with specific pathogens directly
Term
Relative to the transmissibility of the influenza virus (which causes the flu), the transmissibility of HIV is considered to be
Definition
lower
Term
A hybrid swarm is formed when
Definition
two species are sympatric only along the intersection of their range margins, where hybrids can be formed. The hybrid individuals are localized only in this are of overlap, and do not spread effectively into the parental population
Term
Sympatric speciation is generally though to be "more difficult" than allopatric speciation because
Definition
sympatric species must somehow establish separate lineages, even though mating with one another would seemingly be easy
Term
The two things that are required for speciation to occur are
Definition
splitting of lineages followed by divergence between those lineages
Term
A vivariance event which has resulted in speciation can be distinguished from an episode of colonization as a source of species formation, because:
Definition
the two closely related species co-occur with other pairs of species of other organisms, all of which can be shown to have formed at about the same time, as if by the same underlying event
Term
Plants are more likely than animals to undergo speciation by polyploidy because:
Definition
-their cell division and developmental pathways are more flexible
-they are often able to reproduce asexually
-many plants can self-fertilize, and thus a new polyploidy individual is able to reproduce with itself and give rise to fertile offspring
Term
Virulence
Definition
how damaging a disease is once it has infected its host
Term
GP120
Definition
a cell surface protein found on some immune cells that is critical for HIV to gain access to these cells
Term
fever; inflamation
Definition
an example of an immune response to infection that is part of the innate immune system
Term
MHC-II
Definition
protein are "self proteins" only found on cells of the immune system
Term
MHC-I
Definition
proteins are "self proteins" that can be found on virtually any cell of the body (except for red blood cells)
Term
Killer T cells
Definition
when activated, this specific type of white blood cell is able to directly attack body cells that are infected with a specific pathogen
Term
The number one cause of death in individuals with AIDS is
Definition
immune deficiency
Term
the first step which has to occur to begin the process of speciation between two initially similar populations is the cessation of
Definition
gene flow between populations
Term
if two species are able to mate with one another, but the hybrid zygote they produce is either inviable or sterile, this is called
Definition
post-zygotic reproductive isolation
Term
Allopatry
Definition
A type of geographic distribution in which two species occupy different ranges and never co-occur in the same region
Term
reinforcement
Definition
Term
the idea that species are branch-tips on a phylogenetic tree is central to the
Definition
phylogetic species concept
Term
In soapberry bugs and some other species, different species are able to arise even though the populations all occur together in the same habitat and geographical area. This kind of speciation is called:
Definition
Term
A species of lily with a haploid chromosome number of n=4 will have a diploid chromosome number, in its adult cells, of
Definition
8
Term
A species of lily with a haploid chromosome number of n=4 will produce gametes with a chromosome number of
Definition
4
Term
If the diploid adult of a species with n=4 undergoes a mitotic error which doubles the chromosome number of its cells, the cells will now contain how many chromosomes?
Definition
8
Term
If this now tetraploid individual is able to produce gametes by normal pairing in meiosis, what will the chromosome number be in those gametes?
Definition
12
Term
Suppose that a gamete from this tetraploid (a pollen grain) fertilizes the egg cell of a diploid individual from the same population. What will be the chromosome number in the fertilized egg (the zygote)?
Definition
12
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