Category: Biology 10

Have you ever done strenuous activity and suddenly finding yourself breathing hard?  Your heart is pounding and you are gasping for breath.  When this happens, is it because there is not enough oxygen in your lungs or do you have too much carbon dioxide?

The quick and easy answer to this question is: there’s too much carbon dioxide in your blood.  But what does your body do when it detects this?

When there is too much carbon dioxide, or Co2, in your bloodstream, the breathing control centre in your brain (the medulla oblongata) will send signals to your lungs to contract and relax harder to balance out the oxygen and Co2 in your blood.  While this is happening, the cerebrospinal fluid that is in your spinal cord is absorbing the Co2, and other chemicals, from your blood and converting it into ions.  These ions will help control the pH in your bloodstream, making it easier for you to breathe.

As you can see, while you may be panting and puffing for air, your brain is sending out all sorts of signals to the rest of your body to help you catch your breath.  Next time you find yourself gasping for breath and you are looking for someone to blame, you can blame your brain for making your lungs contract and relax so fast.

Thanks for reading!

Many say that animals are not as smart as humans, and while I agree with that statement, I also believe that we should not underestimate the intelligence of animals.  In this essay, I am going to convince you that animals are not as dumb as you may think.

Firstly, how should we characterize intelligence in animals?  In the video lesson this week, Mr. Bear listed a few characteristics of intelligence that can be found in animals:

1. Visually dominant sensory system
2. Recognizes members of their own group
3. Uses tools for hunting, cleaning, etc.
4. Cooperates in hunting and other activities (coordination of efforts and recognition of rank)

When thinking about animal intelligence, many people think of primates.  Primates include chimpanzees, orangutans, gorillas, and other types of apes.  They are considered intelligent because of the large size of their brains and their developed neocortex. 

Primates have shown to be very social, and to even have social ranks amongst themselves.  What is surprising is that primates have a large range of emotions that were thought to only be possible for humans to experience/exhibit.  Primates are also very affectionate and caring to one another.  There have been stories of female chimpanzees and gorillas adopting orphans of their own kind.

Chimpanzees have been taught sign language to communicate with humans and each other.  But even those who live in the wild have been seen to use hand gestures to communicate with one another.  They show physical signs of affection like holding hands or patting each other on the back, much like humans do.

Another group of highly intelligent animals are elephants, who are one of the few species to be born without instincts.  Like humans, they must figure out how to survive in the world.  The majority of this learning process happens during the first ten years of their lives.  Elephants not only have the ability to retain long-term memories, but they can also experience and perceive a wide range of emotions.  This is because of their very developed hippocampus, which is the part of the brain that stores memories and emotions.

A less well known fact about elephants is that they have a ceremony, or ritual, to mourn their dead.  While it is not as intricate as human’s, they have been seen caressing or touching the deceased member while making consistent low groaning noises.  If a herd passes an elephant that is already deceased and reduced to a skeleton, they will pay their respects before moving along.

As you can see, animals are not as unintelligent as you may think.  They may not match the intelligence of a human, but they are definitely not brainless.

Thanks for reading!

Every species on Earth, no matter how annoying or terrifying, has a purpose.  When someone says the word “scorpion”, the first thing most people think of are their pincers and painful venom.  But what if I said that the venom of a scorpion could benefit humans?

Scorpions are known for their pincers and poisonous tail.  But what many do not know is that scorpion venom, unlike the venom of other arthropods, is comprised of several different poisons.  This is because the scorpion hunts several different species.  A poison that may work on one creature might not work on another.  Their venom is known to contain neurotoxins and enzyme inhibitors, which will kill any of a scorpion’s prey.  To humans however, scorpion venom is not deadly unless your immune system is already compromised in some way.

The Deathstalker scorpion, scientifically known as Leiurus Quinquestriatus, carries isolated enzyme inhibitors in their venom.  These isolated inhibitors can, hypothetically, be modified and used as a way to bind with brain tumors and kill the tumor without affecting the nearby healthy cells.

If a scorpion’s venom can do this, imagine what other arthropods’ venom can do after being researched and modified.

As you can see, scorpions can be very beneficial to humans.  Even the most frightening animals can have important benefits to humans.

Thanks for reading!

In the animal world, different patterns and structures have been discovered, but they all follow the same “body plan” in one way or another.  Hox genes are responsible for these patterns.  These genes are a class of their own that encodes transcription factors during the development of an animal during their embryonic phase.  What kind of patterns have humans discovered in the animal kingdom?

Researchers have established that majority of animals follow two types of symmetry.  The first type is known as radial symmetry.  To fully understand this, imagine you have a stool and you cut it in half.  There is no way to tell which is the right side and which is the left side.  However, if you cut it through the middle, it would be obvious which is the top and which is the bottom.  This is radial symmetry.

The second type of symmetry is known as bilateral symmetry.  Animals that fall under this category have distinguishable front and back, top and bottom, but lack obvious signs of left and right.  Majority of the animals in the animal kingdom follow this kind of symmetry.

These patterns are formed by the Hox genes I mentioned earlier.  During the embryonic stage of an animal’s life, the Hox genes act as supervisors over where everything goes.  They make sure that the organs are put in the right order, then they create the other parts of the body like the head, the tail, etc.

As you can see, every animal follows some sort of pattern and structure.  The symmetry I described earlier are one of the characteristics scientists pay attention to when they are trying to categorize animals.

Thanks for reading!

Soil.  An essential component in the growth of a healthy and happy plant.  It is so important that there are not one, but two studies dedicated to soil.  Since Kindergarten, children are taught that soil is important.  But what if someone said “it’s just the thing that holds up the plant.”  What can you say to that?

Soil does help keep the plant stay upright, but it is so much more important than to only “hold them up.”  Soil has horizons, which are like layers.  Each layer carries its own nutrients for the plant to absorb when its roots grow into it.  The first level of soil is known as Topsoil (original name, I know), which carries the minerals needed for Cation Exchange (the process of a plant releasing and absorbing positively-charged particles).  A plant will release or absorb these particles to create the perfect kind of soil they need to thrive.  You can say that plants need soil to grow and survive.

Now what if that same person responds with “if soil is so important, why can’t a plant survive with only soil?”  Plants are like humans in this way.  We need sleep, food, and water to survive.  Plants need soil, sun, and water to survive.  Humans cannot only survive on sleep the same way plants cannot only survive after being put into the soil. 

As you can see, soil is extremely important to the health of a plant.  If you ask any gardener, they will tell you that the different types of soil is crucial when taking care of a plant.  I hope you learned something from this essay along with the imaginary person asking questions.

Thanks for reading!

Plants are one of the most important and crucial parts of a human’s diet.  Without plants, we would not have our fruits, vegetables, bread, and rice.  But as humanity evolves and grows, plants may become more than a food source.

Studies show that plants can be used as a source of energy and fuel in the near future.  When a plant goes through photosynthesis, they create hydrocarbons.  The excess hydrocarbons that are not needed go back into the soil through the plant’s roots.  The organisms in the soil will break down the hydrocarbons, creating electrons.  If scientists and engineers can find a way to harness the electrons, we could have a new energy source.  This makes plants even more important than it was before.

One of the questions I have to answer for this essay topic is: why are plants more important now compared to the past.  Personally, I think the answer is quite simple.  In the past, we did not have the technology or knowledge to realize that we can utilize plants in other ways.  While we still do not have the technology to use plants as an energy source, it does not mean it is impossible.  It simply means that it is a piece of technology we will see in the future.

As you can see, plants are extremely important to humans.  Many people are talking about “green energy” as an alternative from fossil fuels.  If this method proves to be sustainable and viable, it would be a great way to slowly start getting rid of fossil fuels!

Thanks for reading!

Photosynthesis is the process of plants turning light energy into chemical energy for themselves.  There are several cycles that are light dependent, but the Calvin Cycle is the only cycle that is supposed to not need light to process and create energy.  Is this true?

The Calvin Cycle is unique because it does not depend on light, unlike other photosynthesis cycles, but many can argue the Calvin Cycle is indirectly dependent on light.  The Calvin Cycle is started, or triggered, by ATP (adenosine 5′-triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate hydrogen), which are molecules that are created from light-dependent reactions.  Without these molecules, the Calvin Cycle would not be able to start.

For those who do not know, ATP is an energy molecule.  All life forms, not only plants, need ATP to survive.  For humans, without ATP we would not be able to move or think because we would not have energy.  NADPH is a product of the first phase, or level, of photosynthesis.  It is the trigger for the second phase of photosynthesis.

As you can see, the Calvin Cycle is not directly dependent on light, but still needs it.  This proves that photosynthesis is not possible without some form of light.

Thanks for reading!

The official definition of taxonomy is the “orderly classification of plants and animals according to their presumed natural relationships.”[i]  Do not confuse it with taxidermy, which is the process of preserving the bodies of deceased animals.  If you are like me, you may be wondering why something so simple as classifying living organisms needs a fancy name.  It is because the science of taxonomy is incredibly important.  Here’s why.

When the process of taxonomy was first created, there were only two ‘kingdoms’ to classify organisms under: plants and animals.  This worked well until people realized there are organisms that fit under the description of plants and animals.  Eventually, the two kingdoms expanded into five: animal, plant, fungi, protist, and monera.

But even these five kingdoms can be very broad.

The system that we use is known as Linnaean Classification.  It is considered to be the best system because of its binomial nomenclature and its hierarchical nature.  What do these terms mean?  Binomial nomenclature means having two names, genus then species.  For example, the name for a tomato (according to Linnaean Classification) is solanum lycopersicum.

Hierarchical nature means it is classified in the order of life, domain, kingdom, phylum, class, order, family, genus, and species.  The scientific names are only genus and species so we don’t have long, nine word names for everything.

Taxonomy may seem unnecessary and complicated, and for the common person, it is.  But for biologists researching living organisms, it is good to have a common name for everything.  While the system does have its flaws, it is still advanced enough for scientists to use it and not get confused.

Thanks for reading!

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[i] “Taxonomy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/taxonomy. Accessed 14 Sep. 2022.

This week in class, I learned that trophic levels are so much more important than people think.  Each level in a trophic structure affects those above and below it.  In this essay, I am going to use an example of a five-level trophic system to show how each level impacts the others.

For this example, imagine there are five trophic levels (from bottom to top): plants, crickets, mice, snakes, and hawks.  Let’s say that there is a sudden increase of hawks in the area.  What would that do to the other levels?

An increase of hawks means a decrease of snakes since there are more predators feeding on them.  A decrease of snakes will lead to an increase of mice since there are less predators feeding on them.  An increase of mice leads to a decrease of crickets, which causes an increase of plants.

If this continues, the snakes will eventually go extinct in the area.  Extinction of snakes means the mice population will continue to grow and feed on the crickets, eventually causing an extinction of crickets as well.  The plants will start double in production, and probably would cause the area to become overgrown since there are no more crickets to eat them.  Now the hawks could either stay and feed on the mice, or migrate to a more snake populated area.

As you can see, in a trophic structure, every animal and plant rely on each other, especially their predators.  A change in one level will cause changes in other levels.

Thanks for reading!

Estuaries: the transition point of river and sea.  The incredible phenomenon is not only mesmerizing to watch, but it is also home to hundreds of water animals and plants.  In this essay, I am going to talk about what life is like for inhabitants of an estuary.

Estuaries are considered to be on the edge of an aquatic biome, which is the scientific name of aquatic habitats.

Several plants and animals are able to thrive in the ecosystem an estuary creates.  Some examples are “microflora like algae, and macroflora, such as seaweeds, marsh grasses, and mangrove trees (only in the tropics).”[i]  Organisms that live in these areas must learn how to adapt to the salinity in the water and the swell of the tide.

An example of these organisms are Blue Crabs.

Blue Crabs need different levels of salinity throughout their life, making them a compatible species for an estuary. Adult female Blue Crabs have a high-salinity preference, while adult male Blue Crabs have a low-salinity preference, causing them to live in different areas of the estuary.  However, during mating season their preferences overlap, allowing them to reproduce with one another.  Once the process is complete, the female crab will go offshore to lay her eggs in the high-salinity environment.  These larvae, known as zoeae, will live in this area until they develop into megalops (young crabs), which is when they will return to the estuary.

Once returning to the estuary, they will do something known as vertical migration, which is swimming up and down the estuary based on the tides and light they are receiving.  Eventually, they will settle down in shallow water banks to “feed and gain protection from predators.”[ii]

As you can see, the estuary is an incredible ecosystem but not an easy one to live in.  Every plant and animal must be able to adapt to the constant change of salinity and tides.  From the example of the Blue Crabs, I am sure you can see how the salinity levels can affect the behaviour and life of an animal in an estuary.

Thanks for reading!

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[i] “Aquatic: The Wild Blue Yonder.” The World’s Biomes. https://ucmp.berkeley.edu/glossary/gloss5/biome/archive/aquatic.html. Accessed 9 Sep 2022.

[ii] NOAA. “Adaptions to Life in the Estuary.” National Ocean Service. https://oceanservice.noaa.gov/education/tutorial_estuaries/est07_adaptations.html. Accessed 11 Sep 2022.