Biology

I am wondering how fever causes rise in temperature, or fever might itself be rise in temperature. Our body temperature rises or falls when we experience fever. But, according to first law of thermodynamics, heat must travel from hotter to colder region, balancing the temperatures. Why doesn't this happen when we encounter fever?

ALL nucleated cells present MHC class I. 1) B cells and macrophages nucleated, correct? therefore they should have MHC I and MHC II (since they are antigen presenting cells too) If not, why is it the NK cells don't kill them due to lack of MHC I? 2) Why don't NK cells kill our red blood cells since they are non nucleated? 3) What is the most abudant type of lymphocyte in the blood of a healthy individual? I am an undergraduate student with hope of getting into medical school. These are NOT homework questions but rather just me trying to understand what I am missing here on the first 2 questions, along with the true answer for number 3. Thank…

is the size of the fruiting bodies of mycorrhizal fungi such as truffles proportionate to the size of the host tree?

Hello everyone, I have to write a simple essay about this,I know what to write but I'm stuck with the stimulus so can't start the essay. My text book is so vague. I want to know the stimulus in a haemorrhage. 1. Is it the decrease in renal perfusion pressure detected by afferent arteriole that secretes renin. 2. Or decrease in sodium chloride deteced by the macula densa that stimulates it. Thanks

Red-capillary Purple- Basement membrane Blue-podocyte Hello everyone, Now my question is after something if filtered from the capillary how does it go to the podocyte. The basement membrane looks too thick with no pores to me, it seems to be blocking the passage of molecules. Thanks

i'm suffering with a problem that there is lot of fungus in my kitchen, everything gets spoil due to this in two or three days. what should i do?

The question is give an example of post translational modifcation of a protei brought about my vitamin A. Now I checked my book which says vitamin A plays a role in vision, reproduction, growth, maintenance of epithelial cells. I checked the net as well couldn't find the answer . Can anyone tell me the name, so I can search info about it, some info would also be good if possible. Thanks

Hi my name's Rachael and I'm currently looking for a science project involving cryotechnics. I can afford to spend a bit of money on this project as i can apply for CSIRO crest award funding that could be about $500. Thanks so so so much

Goats, buffalos, and other hoofed mammals have been noted to migrate away from areas which are about to be struck by earthquakes, but they do this long before humans are able to sense any impending shifts. One theory offered to account for the ability of these animals to sense oncoming quakes is that they somehow perceive the electromagnetic effects of rocks being fractured in the processes leading up to earthquakes. But if this is so, then why don't human mammals have this same capacity?

Is there any specific season of fungal growth? i have lot of fungus in my kitchen. do i prevent spoiling by putting eatables in freezer

So this is a topic I am studying. Under the economic benefits section, there's a line that states "wild varieties for breeding programmes" I then need to do further research around this statement. However, I don't understand it. What is this trying to say?

Is it more healthy to eat breakfast first before brushing your teeth in the morning or is it more healthy to brush first and then eat breakfast? What does everyone usually do first? And according the most recent scientific findings which order is best to do?

http://www.sciencedaily.com/releases/2011/02/110222140544.htm Following the read, I would assume that the structure is utilized not only for sight, but because you internally visualize different things. even if a blind person is blind, does that not mean he/she cannot visualize what they feel, smell, taste? thoughts?

Hello everyone, From this pic it looks like air can go to oesophagus if you breathe from nose, but this is not happening. Is their some sphincter for this, or what? Thanks

http://www.gizmag.com/color-changing-plants-detect-pollutants-and-explosives/17915/ I was reading this article about research groups trying to engineer plants so that they change colour is they detect explosives or high levels in the air. At the end of the article they outline the aim to have them in places like airports so that the authorities can detect explosives in the air. To me, this seems like a good idea, seeing as plants tend to be in these highly sensitive area anyway and why not make them useful? I am assuming, however, that these plants have been genetically modified and so how will the legal/enviromental problems be dealt with. I know that genetical…

Hello everyone, Ok in the cerebralcortex I saw a pic where there is upside down HAL, the brain controls head,arm, leg upside down. Now I don't know much about this area. I know there is only motor cortex, so are these areas referring to axons that are coming out of motor cortex and supplying these correspondinga areas. Thanks

When stimulated in the middle of axon, nerve conduction is bidirectioal. Now I know the andromic conduction stops at the first synapse. Is the reason for this, that there are no neurotransmitters in the body of a neuron, and more importantly no calcium channels there to activte them. Thanks

Ok I read in internet, that they stop the formation of prostaglandins which are required to make the stomach mucosa. How do prostaglanding affect stomach mucosa? Also since it is an anticoagulent it should make the bleeding worse. Thanks

Hello everyone, I read many articles on this, but they all just say what it is and does not mentions how it occurs. This is a quote from another user not from here. 1. So if sodium channels go into locked position, does this increase the threshold for the stimulus. Let's say if previous threshold was -20, and then sodium channes got locked in, but threshold should stay the same right, it is just that there is a barrier to reach the previous threshold. 2. How do sodium channels get locked up, and does this decrease the frequency of action potential or inhibit? 3. How do we adapt to smell? 4. For receptor changes I'm assuming, that displacemnet of lamella in…

In acute blood loss both RBC and fluid is lost, so why doesn't haemotocrit stay normal. I know compensatory mechanism would increase the fluid, eg kidney. But red blood cell prodcution would take few weeks. Is that the reason haemotocrit decreases? Thanks

This enables them to make haemoglobin. How? They still require mRNA, they don't have a nucleus. So how are ribosomes going to help? Thanks

I noticed my Daphnia magna cultures are beginning to proliferate, the days are getting longer and unicellular algae is starting to replace the strings of hair algae. I've noticed as the Daphnia magna start hatching out of resting eggs the daphnia are quite large, some as much as 6mm or more across. My 6500 gallon vat has the biggest daphnia, i was wondering if anyone else has noticed their daphnia cultures coming back and if the Daphnia are bigger than they are when the weather is warm? All these daphnia are females giving live birth, the males are absent and will not appear until September or October. I am thinking that the evolution of the population of large daphnia at…

During spinal shock, are all spinal reflexes gone, or only reflexes below the lesion. Thanks

Hello, Ok I asked the biochem teacher and she said, there is muscle breakdown in DM, and then creatinine leaks out of muscle. Now my question is DM there is only breakdown of protein in muscles, muscle it self doesn't break apart right ( I mean if so muscle cells can not grow back right), so how does creatinine leak out if there is no damage to the muscle. The teacher is with the idea muscles grow back (teacher is not bad but I think she just doesn't know this point). So if anyone can tell me how creatinine increase in DM. That would be great. Thanks

How is science ever going to build an accurate database on microbes if they are constantly changing due to HGT? Don't they obtain a new identity with new genes added to them or genes they give away? These critters are mind boggling and they are a continuous source of frustration because they are involved in everything from life to non life in chemical reactions. We cannot solve the mysteries surrounding our DNA until we understand their DNA that is a big part of our beings.