Category: Biology

By Anupum Pant

Flatworms are hermaphrodites. That is, each individual has both male and female reproductive organs. But to make new baby flatworms they still need to find a mate and once they do, it is an interesting thing that ensues.

The process of mating involves two flatworms fighting, over who’d be the father and who the mother. Or more specifically, the flatworms involve themselves in penis fencing. One tries to stab the other with its “double barrelled inseminater.”. While both the flatworms resist getting stabbed.

By Anupum Pant

In the Arizona sun it’s hard for you to walk east in the morning and west in the evening if you aren’t wearing sunglasses. Okay, maybe that’s an exaggeration, but sunglasses make life much easier. Add to that a hat and it’s bliss to walk in the sun (not so much). But hats are not the point of discussion today.

Sunglasses come in a variety of shapes and sizes. Of course you get cheap sunglasses that give you the swag. And then there are the expensive ones which might look the same but come with added features.

One such feature of the expensive glasses is UV protection. While cheap glasses rarely give you that. How bad that could be? At least they shield you from the intense light, right? Or so you would think.

Cheap glasses which do not offer are actually affect your eyes negatively. You are better off wearing no glasses at all. That’s because when they shield you from the intense light, due to their tint, they make your eyes relax and your pupils dilate. That allows more radiation inside. That means more UV goes in and damages your cells.

The Royal Institution explains…

By Anupum Pant

A fatal disease called Chagas disease is transmitted to humans from an insect bite. Presently it affects about 15 million people and causes 50,000 deaths every year.

The disease is carried around by the triatominae family of bugs, or also known as kissing bugs (kissing because they like to bite the face of humans, as it is the part of the body that is usually uncovered during the night). The insect looks like this and usually dwells in old homes or in the wild.

At home, it can be spotted with feces marks on the walls or by spotting the insect itself. If you live in the southern part of USA or somewhere between there and Argentina, you could be close to these insects.

Acute-phase symptoms of Chagas disease may be swelling and/orredness at the skin infection site (termed chagoma), rash, swollen lymph nodes, fever, head and body aches, fatigue, nausea, vomitingand/or diarrhea, liver and/or spleen enlargement, and the Romaña sign.

By Anupum Pant

When we picked up speaking as our form of communication several million years ago, gibbons chose singing. We got better at speaking and gibbons mastered singing. Singing like opera takes years of practice, but for gibbons it comes naturally. They are much better than us at it. Plus they do this using precise control of their vocal tract – something which was previously thought could be done by only humans.

By Anupum Pant

Goat eyes, like other ungulates, are rectangular in shape. They are pretty alien to look at. These awkwardly shaped pupils actually serve a very practical purpose for them. It enables them to have a great depth perception and great detail perception for a wide angle of the field of vision – for about 280 degrees! That means they don’t have to rely on their peripheral vision to spot a predator coming from behind them. Their peripheral vision is as good as their main vision, is what I’m saying. But the downside of this blessing is that they aren’t able to see very well on the vertical axis.

The other funny thing about goats is them suddenly going stiff and fainting when they are suddenly made to panic, or scared. Actually, when they do this, the goats don’t really faint. But this happens due to a heriditary genetic disorder, like seen in some humans and other mammals too, their muscles aren’t able to relax quickly after they get stiff due to some reason – usually when they go stiff all of a sudden.

And more about on goats here…

By Anupum Pant

Writing physically, with your pen and paper can be called an art form now, which is dying off. Who, besides students and a few others, write any more? It’s tough for me to pick up a pen and actually write. I’d rather type it out.

Even though you don’t, you probably should. Because when you write, a lot happens in the brain and recent MRI scans of people writing a creative passage have revealed brain activity which looks like that of sportsmen when they are playing.

If nothing, your whole brain works when you write, it is a great exercise for the brain.

By Anupum Pant

The octopus is an incredibly intelligent creature, like the crow. Their brains are literally all over the place. And let me not even start talking about how well they can blend into their surroundings.

Julian Finn, a researcher from the Victoria Museum in Australia, a few years back, observed an octopus displaying amazing foresight. It was seen scooping up a halved coconut shell and carrying it around, walking on the bed of the water body. It wasn’t clear as to what it was planning to do with it. The researcher laughed so bad, he almost drowned when he saw this happen.

As you’ll see in the video below, the octopus uses this shell as a makeshift shelter and carries it to places where it might not find good places to hide.

The carrying around isn’t as simple as it seems, it takes a lot of processing power. And to expect it from a octopus isn’t normal. The octopus first digs them out, arranges then so the open halves are facing up, then blows jets to clean the mud inside them, scoops them with its arms and walks away with them. Later it sits down and lets the coconut shells make a shelter for itself.

via [BBC]

By Anupum Pant

Last semester I took a course, some part of which dealt with the optical properties of materials. There I learnt a lot about how saying something is transparent and something else is opaque is meaningless unless you mention the particular wavelength you are talking about.

So, take your average glass for instance. It’s fairly transparent in the visible spectrum. So you see it as transparent, and nothing more. If you go ahead and increase the energy of light, thereby decreasing the wavelength, at some point the glass will become opaque. Similarly, a typical metal would look opaque to you because it is opaque in the visible spectrum. However, as you increase the energy of em radiation and move into the ultraviolet region, metals start becoming transparent.

The lens of your eye works like a typical glass. It’s transparent in the visible region, but becomes opaque as the energy increases and goes to the UV range. That’s the reason UV doesn’t get inside and you don’t see in UV. Had there not been a lens there,  your retina would have received UV and you would have been able to see some part of UV (from 400-300 nm wavelength).

This actually happens to people who, due to complications in the eye, like cataract and other diseases, have to get their natural lens out. This absence of lens is called Aphakia. These people start seeing a part of UV, usually from 400 to 300 nm and see the normal white light as a bluish white or a violet white light. That is because, due to the UV being detected by the blue cones in their retina, their blue cones get excited more than the others.

By Anupum Pant

A new study published in Nature communications discusses about the make up of this slime a hag fish produces. This slime is probably used by them to make their bodies more slippery so the predators find it hard to grab on, also they sometimes block the predator’s gills.

But what looks like slime actually, the researchers say, is composed up of thousands of fine strands, each only 12 nanometres in thickness. Despite the delicate appearance, these strands are able to stretch by about 15 centimetres. They keep this biological thread tightly coiled up inside a gland and it never tangles inside. The stress that this amazing biological material can take is about 5 times more than that a normal steel can take.

more at [Nature Communications]

By Anupum Pant

In the tropical rainforest waters of South America live a variety of toads called the Surinam toads (pipa pipa). The way their females give birth is pretty weird, almost as much as the frog we saw a couple of days ago.

During the mating season these toads find mates and the female lays about a hundred eggs. The male catches these eggs, fertilizes them and puts them on the back of the female. The eggs go under the skin through the tiny holes on the back of the female toad. As them go in, a protective layer of skin grows on top. When the eggs get hatched the young ones start punching up to break the protective layers and literally come out of the skin of their mother.

By Anupum Pant

While animals are often tranquillized using tranquillizing darts, there’s no such reliable instrument for humans because of two main reasons:

1. The amount of dose has to be varied after the weight of the creature to be sedated is estimated. If the dose is far too less, there isn’t proper effect and if it is too much the animal would die. There’s no way of estimating the weight and changing the dose quickly enough to deal with humans of various sizes.

2. The tranquillizer has to go through the blood stream for it to take effect. So, it usually takes a couple of seconds to sedate an animal. So, if a dangerous human advances towards a police or military personnel with a dangerous weapon, these several seconds might prove to be dangerous.

Thus military and police use the electroshock weapons like TASERs to deal with dangerous humans. While tranquillisers are fine to sedate animals.