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Biology 10, Lesson 40 – Cancer

Cancer: one of the most destructive diseases known to mankind.  It has been around for decades, yet doctors still cannot find a cure for it.  We do not know much about the disease, but what we do know is that it is alive.  It is not contagious, and it is extremely dangerous to those who contract it.  In this essay, I am going to talk about what cancer is and how it works.

Cancer, like many diseases, is alive.  It seems to be caused by certain mutations in your genes that will damage your DNA sequence.  When your cells try to repair what has been harmed the mutations will start to grow, causing tumours.

You may be wondering why doctors have not found a cure if they know how cancer is caused.  The problem is that finding a cure is not very specific.  Not only are there different kinds of cancers and stages, the cancer will keep mutating and growing.

There are instances where the cancer is found at an early stage, allowing doctors to give the patient certain ways to prevent it from growing.  But for those who did not find it until it progressed in larger, more destructive stages, there is no cure.

For those who are wondering, chemotherapy is not a cure.  It is a treatment to kill the mutating cells that are causing the disease.  However, this treatment kills all cells, healthy and non-healthy.  This therapy is very physically, as well as mentally and emotionally, taxing on the recipient.  Unfortunately, there are many cases of people stopping treatment altogether because it is too difficult for them to continue.

A common misconception, mainly from young children, is that cancer is contagious.  Doctors have determined that cancer is not contagious.  It can be inherited genetically, but you cannot contract the disease if you are physically close to a person who has it.

As you can see, cancer seems to have a somewhat simple cause, but it has affected the lives of thousands of people.  While the human body has its incredible abilities, it also has a way to self-sabotage itself.

Thanks for reading!


Biology 10, Lesson 30 – Non-Hereditary Genetic Disorders

I am sure you have heard of several diseases which are hereditary, like diabetes and sickle cell diseases (red blood cells form in unusual shapes and can cause blockages).  But did you know that there are several other diseases that are not hereditary?  In this essay, I am going to talk about what can happen during a pregnancy that can lead to a child developing a non-hereditary disease.

Every human has 46 chromosomes.  Each chromosome has a number based on where it is in the chain of chromosomes.  Sometimes the chain can “glitch” and accidently delete a chromosome or copy it too many times.  When a “glitch” happens, it is known as aneuploidy.

An example of aneuploidy is trisomy, which is when a chromosome copies itself three times instead of only twice.  An example of trisomy is Down Syndrome, which happens when Chromosome 21 copies itself three times.

There is also the case where there is only one copy of a chromosome, known as monosomy.  This can be fatal to the baby.  However, majority of the cases of monosomy are females who have Turner’s Syndrome, which is when the X chromosome is missing or is not complete.

There are other mistakes that can happen, like polyploidy (multiple copies of a chromosome), deletion (a part of a chromosome is “deleted”), inversion (parts of DNA are swapped or reversed), and translocation (part of a chromosome is moved from its proper place).

Translocation is suspected to be linked to Leukemia.

As you can see, despite our bodies being amazing creations, mistakes can happen.  Now, if you ever hear about a disease that is known to be non-hereditary, you can understand how it came to be.

Thanks for reading!

Biology 10, Lesson 170 – Bone Marrow

When you think of your bones you probably imagine them as the hard, white things in your body that keep you upright.  But have you ever thought about what your bones are made up of?

Our bones are so much more complex than you can imagine.  Each bone is made up of an intricate matrix of collagen, calcium, and phosphorus.  We also have thousands of cells and nerves inside of our bones.  This is why we feel pain if we hurt or damage the bone.

You have probably heard the words ‘bone marrow’ before, but I doubt you truly understand what it is.  I am sure you can imagine how crucial bone marrow can be to our bones from the name.  Bone marrow is found in long and flat bones like our shoulders, hips, and ribs.  There are two types of bone marrow in our bodies: red marrow and yellow marrow.

Red marrow creates red blood and stem cells, which can be made into osteoblasts.  Osteoblasts are ‘immature’ bone cells that help create the minerals our bones are made out of.

Yellow marrow is mostly made of fat cells and do not do much.  Their only job is to support the red marrow’s activity.  Something interesting to take note of is the yellow marrow’s ability to turn into red marrow.  If you have a serious injury, like a gun wound, and you lose a lot of blood, the yellow marrow will convert itself into red marrow to create more red blood cells to help make up for the loss of blood.

As you can see, bone marrow is a really interesting and crucial part of our bones.  Like many children my age, I have heard the term before on TV shows, but I have never considered what it may be and why it is important.  The human body never ceases to amaze me with how important every little cell and fluid is to our everyday functioning.

Thanks for reading!

Biology 10, Lesson 160 – Osmoregulation in Marine Mammals

This week in class I spent a lesson learning about osmoregulation.  In simple terms, osmoregulation is the “maintenance by an organism of an internal balance between water and dissolved materials regardless of environmental conditions.”[1]  In this essay, I am going to talk about osmoregulation of marine mammals.

Every marine mammal lives in different conditions and has different processes of regulating the water and salt in their bodies.  For example, salmons are considered fresh and salt water fish.  The biological term for them is osmoconformer, meaning they can maintain equilibrium in their cells based on their current environment.

But for the marine mammals that are not special like salmon, they have their own struggles.  Saltwater animals have the risk of drinking too much salt and not enough water.  In response, the excess chloride (salt) ions are removed by active transport (the movement of dissolved molecules into or out of a cell through the cell membrane)[2] and leave the body through the kidneys or gills.

On the other hand, freshwater animals have the risk of taking in too much water and not enough salt.  Freshwater animals tend to drink little to no water and urinate frequently to rid themselves of the excess water.  They will then eat salty foods to balance the amount of water and salt in their body.

As you can see, each marine mammal has their own process of balancing out the water and salt in their bodies.  Salmon and other osmoconformer animals truly are fascinating and unique because of their ability to adapt to any environment.  But for the rest of the fish in the sea (and lakes), they will have to work to keep their balance.

Thanks for reading!

[1] Britannica, The Editors of Encyclopaedia. “osmoregulation”. Encyclopedia Britannica, 21 Apr. 2016, Accessed 5 July 2022.

[2] BBC. “Movement Across Cell Membranes”. BBC. Accessed 5 July 2022.

Biology 10, Lesson 140 – Hunger

This week in class I learned about the human digestive system and how it works.  In this essay, I am going to be summarising the process of hunger and satiety in your body.

The feeling of hunger is created by the ‘hunger hormone,’ scientifically known as Ghrelin.  This hormone gets released into your stomach when your blood sugar starts to get low.  Once you eat, your stomach stretches, telling your Enteric Division that you no longer need to feel hungry.  The Enteric Division, nicknamed ‘the second brain’ because of how intuitive it is, is a mesh of nerves along your alimentary canal that controls the entire process of digestion.  The alimentary canal is a tube-shaped organ that begins at the mouth and ends at the anus.  Once your stomach stretches, the Enteric Division triggers Peptide YY (PYY), a hormone that shuts off the production of Ghrelin, causing the feeling of fullness.

As you can see, the human body is insanely complex.  The simple of function of informing the body that it needs food involves many different organs and hormones to work together.  I cannot wait to learn about the other amazing things the human body can do.

Thanks for reading!

Biology 10, Lesson 20 – Adrenaline

Imagine, you are walking through the corridors of an old, most likely haunted, house.  The floorboards creak every time you step on them and there seems to be an unpleasant energy in the air.  Your heart is pounding and you get shivers every time you pass a door, expecting something to jump out at you.  Right as you are about to turn a corner, a figure jumps out of the shadows yelling “Boo!”  You scream and see your whole life flash before your eyes.  But then you realize, it was only your friend trying to play a trick on you.  The two of you laugh it off and you place a hand on your heart, which is now racing faster than it was before.

You know that the sudden increase of heart rate is due to something called adrenaline, but do you know what causes the adrenaline?

Adrenaline, also known as epinephrine, is a hormone that triggers your fight or flight.  This hormone breaks down your glycogen (a large molecule that functions as a kind of energy), which explains the sudden burst of power you feel.

Going back to my example from earlier, when your friend jumps out at you, three big chemical reactions happen inside of you in a matter of microseconds.  When your body gets the shock of seeing a figure lunging at you, a chemical signal is sent to your cells.  This signal then triggers a series of chemical reactions inside of the cell, preparing it for the epinephrine.  One of these chemical reactions activates the breaking down of glycogen, giving you the energy you require to run out of there if you really need to.

As you can see, adrenaline is a lot more than something that happens when you get scared.  It is a whole process that can get activated and completed in a matter of seconds.  Even though I have not reached the anatomy of the human body in this course yet, I am constantly learning about the chemical reactions our body can do.

Thanks for reading!

Biology 10, Lesson 10 – Metabolism in Simple Terms

Metabolism.  I am sure you have all heard of the word.  Before this week’s lessons, I only knew it in the term “high metabolism,” which to me meant “something the human body does that can make people thinner.”  But after this week’s lesson, I now know why it “makes people thinner.”  Would you like to know as well?

The definition of metabolism is “the chemical process of your body turning food and drink into energy.”[i]

The process of metabolism has two main functions, catabolism and anabolism.  Catabolism is the breaking down of molecules causing a release of energy.  Anabolism is the opposite, the building of molecules causing the buildup of energy.  Catabolism makes the body lose tissue, and Anabolism makes the body gain tissue.

If you ever hear someone say that they have “high metabolism,” that means that certain person’s body catabolizes more than it anabolizes, which makes them naturally leaner than others.

Even though metabolism is a natural thing that your body does, it can be managed.  For example, to speed up your metabolism you can drink more water than sugary drinks.  It is also advised to not skip meals as your metabolism will adapt to it quickly and will start breaking down your muscles to provide your body with the energy it needs.

Fun fact about metabolism: men tend to have a higher metabolism than women because “they have more muscle mass, larger bones and less body fat.”[ii]

As you can see, metabolism is a really cool function your body can do.  If you are like me, and have never studied biology or the human body, you probably knew what metabolism was, but did not actually understand what the use of it is.  Hopefully after reading this essay, you have a better idea of what it does.