Ch 43 Articles Study Guide
Love with the Proper Stranger
Why are people attracted to particular members of the opposite sex?
We are members of a sexually reproducing species and need to join up with someone of the
opposite sex to mate, conceive offspring, and pass our genes onto the next generation
Who are the Hutterites?
Hutterites are people who can trace their ancestry back to the 400 members of the Anabaptist sect
who migrated from Europe to the US who settled in South Dakota. According to geneticists, they
are ideal subjects because the 400 original settlers were closely related and believed to be
descended from 90 individuals. And they are usually inbred because they must marry inside their
own group.
What are the various alleles for HLA and how many exist per? Why are there so many?
Various alleles referred by letters A, B, C, DR, DQ, DP, E, F, and G. There are at least 60 of the
A gene, 150 of the B, 180 of the DR, and so on. At least 80 million combinations are possible.
There are a lot of combinations because the HLA system tells the body to reject tissue that does
not match its own.
What is the relationship between HLAs and pregnancy?
There is a higher risk for miscarriage when a man and woman with similar HLA haplotypes
conceive. Natural selection favors fetuses with HLA genes different from their mothers’.
How did researchers demonstrate that exposure during development (not mate MHC type)
drove mate choice?
When the time came for males to choose mates, they avoided females whose MHC genes were
similar to their foster mothers’, even when that meant winding up in the position of mating with a
female whose MHC genes were similar to their own.
How might people “imprint”?
How did researchers test the scent hypothesis with people?
How contraceptives influence the findings?
Pregnancy Reconceived
What is the immunological paradox of pregnancy?
The fetus is like a semiforeign transplant, because half of its genes come from the father.
Therefore the mother’s immune system and the fetus must be locked in conflict. What are the hypotheses that explain a mother’s tolerance of an embryo? How does
the author refute each?
• The trophoblast forms some kind of mechanical barrier.
Studies indicate the placenta is not as impermeable as originally envisioned.
• The mother’s immune system is suppressed during pregnancy.
If pregnant women were immunologically suppressed, they would’ve died within
hours of exposure to pathogens.
HIV is less likely to develop into AIDS during pregnancy.
• The mother’s immune system is suppressed, but only locally, in the vicinity of the
trophoblast.
Removing macrophages that would be expected to attack the trophoblast cause
pregnant mice to miscarry.
• The balance of cytokines shifts during pregnancy.
Pregnancy can be either a pro- or anti-inflammatory condition based on the
stage.
First and third trimester inflammation occurs, while in the second it doesn’t.
What is FasL?
A protein secreted by trophoblast cells that are said to bind to Fas cells and induce
apoptosis.
What is the anti-inflammatory theory of pregnancy? Cytokine-shift theory?
Cytokine-shift theory (aka the anti-inflammatory theory of pregnancy): pregnancy
changes the balance of cytokines, suppressing the inflammatory response and creating an
anti-inflammatory environment.
Why were findings from testing these hypotheses contradictory?
Some studies found a shift toward anti-inflammatory cytokines in the mother’s blood
while others didn’t.
How are trophoblast cells and macrophages similar?
They both have signal receivers called Toll-like receptors (TLRs) on their cell
membranes that enable trop
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