8
votes
3answers
359 views

Organism identification, what is this?

Im trying to find out what this is, see image below. Im thinking these are either some insect eggs or some sort of mosslike plant. The substance is stuck to a steel pillar, outside, about 5 feet ...
3
votes
1answer
62 views

Are nutrients absorbed in human esophagus?

Following this question regarding absorption in human oral cavity (sadly not yet fully answered), I'm curious if any nutrient absorption occurs during the descent of food through the esophagus. And ...
1
vote
2answers
104 views

How does DNA damage cause ageing in yeast?

As I understand it, in yeast ageing there is daughter cell and mother cell. The daughter cell is has newly "fresh" DNA and mother cell dies after some counts of replication. What happens to the ...
3
votes
3answers
26 views

Kinetic Vs Potential Energy in Biochemical Contexts

This question is causing great confusion in my head. Which of the following is an example of potential rather than kinetic energy? A) the muscle contractions of a person mowing grass B) water ...
2
votes
2answers
35 views

Conversion of glucose to glycogen

Why is excess glucose, as a glycogen, stored in only a limited amount as compared to the lipid in our body? Why is mature glycogen arranged (polymerized) in 12 tiers polymer?
-1
votes
0answers
40 views

What is it a swell in the body? [on hold]

When I get hurt, for example injuries to a bony part causes it to swell...like a little mountain. What is it actually? Does it happen in other places on the body?
-1
votes
0answers
19 views

Microscopic Organism [on hold]

I was looking under my microscope and saw this... I asking about the long organism with a circular head... I observed it moving and wanted to find out what this was. Thank You
4
votes
1answer
29 views

Plural of “dibamus”

Migrated from English site. Dibamus is a genus of legless lizards in the family Dibamidae, of the infraorder Dibamia. Genera are usually given in singular, so what is the correct plural of ...
4
votes
1answer
32 views

Mechanism of Decorticate & Decerebrate Posturing? Also why is only Decorticate Rigidity a misnomer?

I read these two from various books, and got confused. The confusion is - Reticulospinal tracts control gamma motor neurons. Gamma motor neurons control tone of muscle. In decerebrate rigidity, the ...
5
votes
1answer
43 views

Repair wrong DNA pair after ending replication?

If there are wrong DNA pair, for example A=G, is there mechanism that could repair such things - after the replication was finished? Or it happens only during replication?
10
votes
4answers
2k views

Why can cones detect color but rods can't?

I don't know if this question applies to only humans but why can cones see much greater detail than rods? Is it possible to have a rod that can detect light intensity and color?
3
votes
0answers
25 views

How long can a human neuron cell live outside the body in a controlled environment?

Have there any experiments been to keep neurons alive (stationary) without preserving methods such as freezing? If yes, for how long?
4
votes
1answer
43 views

Why do the proportion of predators increase at mass extinction events?

Why does predation surge with mass extinction? It is caused by extreme selective pressures over resource competition that forces certain species to adapt to predatory niches?
2
votes
1answer
38 views

What equipment is needed to perform simple plant electrophysiology?

What is the minimum needed equipment to perform simple plant electrophysiology? I am looking for some simple experiments that I could run at home for learning. Ideally, I would transfer the skills to ...
4
votes
1answer
49 views

Are some facial features more important than others in human facial recognition?

I'm often surprised by the human ability to correctly identify other individuals despite significant modifications due to ageing, hairstyle, injury etc. But, sometimes the addition of a beard and a ...
8
votes
1answer
2k views

What is the female equivalent of the morning erection that some men experience?

There was question about what causes "morning wood." It was answered that the erection in the morning is caused by decline of norepinephrine during REM sleep. Which in part allows to prevent ...
-1
votes
0answers
27 views

Why Muscle Popups? [closed]

I am a swimmer, I swim 6 times a week 3 hours every time. After almost every train when I get to absolute rest, my hand muscle popup... and just lately I have noticed that once in a while my ...
6
votes
1answer
574 views

Have there been studies done to test Immortality of Cancer Cells on culture?

The article here says cancer cells may be immortal. I am wondering if there has been any research done to find if cancer cells are really immortal. How old is the still maintained living oldest ...
4
votes
1answer
17 views

Can methylation of a promoter induce gene expression in some rare cases?

Can methylation of a promoter induce gene expression in some rare cases? I've read somewhere that methylation of an intron can induce gene expression (eg. Igf2). How is that even possible? Thank ...
2
votes
1answer
63 views

Why do moths not die when they fly into a window?

Sometimes at night when I'm inside with a light on, I can hear (I'm sure) moths fly into the window, and it's so loud I can sometimes hear it over the TV from the other side of the room. Since ...
4
votes
1answer
56 views

How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
5
votes
1answer
90 views

Which of the two mitochondorial membranes relate to bacteria according to the endosymbiotic theory?

I seached for endosymbiotic theory in Wiki and I found this about endosymbiotic theory: Symbiogenesis, or endosymbiotic theory, is an evolutionary theory which explains the origin of eukaryotic ...
0
votes
0answers
16 views
7
votes
3answers
15k views

Does Human Female Meiosis II occur after fertilization with sperm?

I am reading the answer and I am getting confused by the sentence: At the end of meiosis I females have two daughter cells and meiosis II only occurs if and when fertilization occurs by a sperm ...
2
votes
1answer
23 views

Does enzyme Km comparisons make sense?

I have encountered comparisons of the Michaelis-menton constant (Km) a few times. They say if Km of an enzyme is higher, then it's affinity to its substrate is lower. How does this make sense? Maybe ...
-1
votes
0answers
26 views

Why the dirt of human ear is yellowish? [closed]

The answer to this questions would help also the people seeking for the natural facts.
1
vote
1answer
42 views

What's the meaning of 'plasma' in 'plasma membrane'?

I wonder why is it called plasma membrane - what's the biological meaning of the word 'plasma'?
2
votes
2answers
92 views

Calcium levels and nerve hyperexcitation

Why does lower blood calcium levels (or lower calcium levels in ECF) cause nervous hyperexcitaton? Why does it cause over stimulation of nerves and muscles and spasmic contractions of muscles? This is ...
0
votes
0answers
18 views

Why can I breathe true only One nostril [duplicate]

just so you know, this is not why I breathe OUT only from one nostril. I am literally breathing with only 1 nostril, I can't breathe in any oxygen true my left one. If I like plug the right nostril, I ...
3
votes
3answers
37 views

why do some cells in the body prefer necrosis to apoptosis as a means of cell death?

There are many programmed cell death pathways, but some cells show a greater preference for some over the other. I'm wondering as to why if necrosis is an inflammatory response that causes damage to ...
7
votes
1answer
45 views

Can people with paralyzed eye muscles see?

As far as I am aware, the saccades of the eye are central to sight perception. If the eye is held still, the human stops seeing, even if light is reaching the retina and the visual pathway is intact. ...
6
votes
2answers
366 views

What are the differences between cancer and tumour?

What are the differences between cancer and tumour? I mean is it in the DNA or shape or something else... And how can a benign tumour turn into a malignant tumour? The body has a lot of tumours all ...
1
vote
1answer
51 views

Role of Calcium and Magnesium in capacitation/acrosome reaction

During the acrosome reaction, the activation enzyme present in the sperm dissolves the corona radiata and zona pellucida enabling the sperm to reach the plasma membrane of the egg. Also calcium and ...
5
votes
3answers
105 views

If someone were to die on the moon, would their body decay?

I heard that the footprints of Neil Armstrong are still there, so I was wondering if someone were to die there, would they remain preserved, too? If not how long would it take for them to decay?
-1
votes
2answers
29 views
4
votes
2answers
33 views

What’s the reason for isovolumic contraction and isovolumic relaxation?

During cardiac cycle, there are two periods in which the heart volume doesn’t change, but there is a change in tension/pressure. It takes about 0.25-0.35 second to achieve this change. I searched in ...
3
votes
1answer
62 views

Trying to differentiate between the three muscle tissues with small pictures

For an assignment I have to differentiate the three types of muscle tissues in these three pictures . I'm having difficulty seeing the striations and branches etc. because the pictures are so small. ...
5
votes
1answer
8k views

Can dish soap really be used to kill ticks and fleas?

An answer at Pets suggested using dawn dish soap to kill fleas. I did a little looking around, and found several references supporting the idea. Most of what I found was in 'selfhelp' and 'save a ...
0
votes
0answers
19 views

Does Pseudomonas aeruginosa have any common name at all?

Pseudomonas aeruginosa is the fifth most written about¹ binomial name of all species. I'm having trouble coming to terms with the possibility that such a well researched and studied organism has never ...
1
vote
1answer
42 views

What specific sensory nerves act as receptors for “pins and needles” (neuropathy)?

According to this excellent answer, the difference between "pain" and "pins and needles" (neuropathy) is that different receptors (sensory nerves) trigger in reaction to different stimuli. Different ...
1
vote
1answer
37 views

How and where do nerves share pathways to the brain?

I am interested in understanding how pain receptors send signals to the somatosensory cortex (the part of the brain that registers various nerve signals such as pain, presure, temperatures, etc). ...
1
vote
1answer
14 views

Why does a tumour's genome change depending on the environment?

According to the book "Primer of The Molecular Biology of Cancer" by Vincent, Theodore and Ateven, the tumour cell is changed depending on its environment. performed genome-wide analysis on three ...
-1
votes
0answers
22 views

How does the intra-esophageal presure affect the lower esphageal sphincter?

I know that the lower pressure in the thorax will cause the esophagus to have a lower pressure but someone told me that this forms a part of the physiologic lower esophageal sphincter. How so? ...
21
votes
1answer
10k views

Why do cockroaches flip over when they die?

This question has always mystified me since young. For beetles, I can reason that they flip over because they have a higher centre of gravity causing them to be in unstable equilibrium when they tuck ...
1
vote
0answers
24 views

Does the metabolic rate determine how fast the telomeres shorten?

In many papers one can read that telomeres may play an important role in longevity. According to Calado et al.1 the telomeres of mice are much longer than the telomeres of humans. However, mice have ...
-1
votes
0answers
29 views

What is the most recent cytokine discovered in human? [closed]

Has anybody found an updated list of all cytokines in humans. I will appreciate that. To the best of my knowledge it is IL-32, is there a more recent one?
1
vote
2answers
35 views

Why are nausea and dizziness such common side effects from medication?

Why are nausea and dizziness such common side effects from medication? If you go through your medicine cabinet and look at side effects, those might just be on every single bottle. Is there some ...
1
vote
1answer
52 views

Why is sarcoma more prevalent and common in right heart?

Ewing's sarcoma or Ewing sarcoma is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. It is more common in right heart than ...
1
vote
0answers
28 views

Largest direct ancestor of humans

Going back the genealogical lineage from present humans to the beginning of life, what was the biggest - in terms of body size or mass - animal in this sequence? More generally, what would a time vs. ...

15 30 50 per page