Exam Discussion

[ChickenCh0wM1en]

It was something like this.

There are four newborns and their mothers when pregnant were infected with the rubella viruses. Antibodies IgM and IgG are produced by the mother. IgM cannot pass through the placenta. Babies haven't been fed.

Baby 1: No antibodies
Baby 2: IgG
Baby 3: IgM
Baby 4: IgM

A - Baby 1's mother had immunity to Rubella.
B - Baby 2 will have 2 years passive immunity.
C - Baby 3 got IgM through the placenta.
D - Baby 4 got infected with rubella during fetal development.

I chose D, as did most others.

Wow amazing memory lol
I really hope it is B though.. cause the babies immune system hasn't developed yet at that stage

If it was passive immunity, isn't that short lived? So like 28 days?
How could it last for 2 years?

[okaykath]

There was question with a diagram of a blood vessel and the cells going through it to the site of a bacterial infection. The options were histamine and natural killer cells and some others. Can anyone tell me what the answer was for this?
And did anyone else find the SA less difficult than the MC?

[MisterTransistor]

'In an infant the presence of IgM antibodies means the baby was infected during the pregnancy.' I got this from http://www.labtestsonline.org.au/understanding/analytes/rubella/tab/test

So i think this would support D

[InsaneMcFries]

I said they were phagocytes. The diagrams of them were kinda odd though.

If you went to the mast cell in short answer, the diagram of it looked the same as the cells that stayed in the blood vessel in the MC question.

[MisterTransistor]

There was question with a diagram of a blood vessel and the cells going through it to the site of a bacterial infection. The options were histamine and natural killer cells and some others. Can anyone tell me what the answer was for this?
And did anyone else find the SA less difficult than the MC?

I was tossed between the natural killer cell option and the phagocyte option. They looked kind of granular so they could have been natural killer cells but i chose phagocytes as I figured neutrophils (which are also granular) could have been what was in the diagram. 

[InsaneMcFries]

NK cells target infected cells not bacteria.

[Gazillionaire]

NK cells target infected cells not bacteria.

'NK cells secrete antimicrobials which kill bacteria by disrupting their cell walls' - Wikipedia.

[spherelin]

It was something like this.

There are four newborns and their mothers when pregnant were infected with the rubella viruses. Antibodies IgM and IgG are produced by the mother. IgM cannot pass through the placenta. Babies haven't been fed.

Baby 1: No antibodies
Baby 2: IgG
Baby 3: IgM
Baby 4: IgM

A - Baby 1's mother had immunity to Rubella.
B - Baby 2 will have 2 years passive immunity.
C - Baby 3 got IgM through the placenta.
D - Baby 4 got infected with rubella during fetal development.

I chose D, as did most others.

Wow amazing memory lol
I really hope it is B though.. cause the babies immune system hasn't developed yet at that stage

If it was passive immunity, isn't that short lived? So like 28 days?
How could it last for 2 years?

it can be passive because the baby could be breast fed after? (The question said babies haven't been fed but ER wouldn't the baby die if they weren't fed for 2 years lmfao?) i was tossing up between D and B but D just seemed really odd... never heard of fetus babies getting infected with viruses,,, but now B seems wrong <_< wtf

[InsaneMcFries]

Interesting, I never considered NK cells as answer. Either way, I'm pretty sure it is phagocytes that squeeze through the capillaries to reach a site of infection.

You can't assume that the baby will be breast-fed to get passive immunity for two years.

[LOLs99]

what did u guys put for MC Q24? I think I put D or A.
This exam is easy but tricky! Thank god there is no experimental design.

Yeah I put D, was considering A after eliminating B and C. changed last moment lol

was D the antigen has the complementary shop to the antibody?

yeah it was

Yeah I was considering A for Q24 at first but after thorough thinking I rub off and put D.
Hey  for the agglutination question , was the answer D - antibodies B was given to blood type AB

[InsaneMcFries]

Yes it was D for the blood-type question.

[spherelin]

Interesting, I never considered NK cells as answer. Either way, I'm pretty sure it is phagocytes that squeeze through the capillaries to reach a site of infection.

You can't assume that the baby will be breast-fed to get passive immunity for two years.

i dont think a baby's immune system develops until after they are born... not full at least. that question is stupid! requires knowledge about babies! HAHAHAH

[InsaneMcFries]

About the capillaries question, in the year 12 course we are only expected to know that NK cells destroy virally-infected cells and tumour cells from what I know of.

[thushan]

The IgM question - the fact that IgM was found in the baby means that the baby HAS to have had some degree of immune system development, otherwise where else would IgM have come from? Cant come from mother, IgM doesn't cross placenta.

And I'd go with phagocytes - in the initial innate immune response, the neutrophils exit the post capillary venules into the site of infection - so those granulocytes that you saw are probs neutrophils.

[LOLs99]

Yeah passive immunity will last for a few months or weeks only.
I found that the SA is easier than SB because I might be unlucky and had a pedantic marker.
I would also pick the phagocyte one because natural killer cells just seem weird somehow and they don't attack free bacteria, just infected cells while macrophages(type of phagocyte) can engulf bacteria and foreign material.