Archivo de la categoría: Biology

Homeostasis: Controlling the Blood Sugar Levels

Our Biology teacher, Magdalena Ravagnan, asked us to work in groups in order to answer a set of questions. I worked with Luna, Nico and Juan.

Last lesson we studied how we control the body temperature.

Another factor that should be kept constant is the levels of glucose in the blood.

Which are they?

Study this web-page for revision.

b) Level of glucose increases »» Brain sends message to the pancreas through neurones »» Pancreas releases insulin »»  Insulin allows glucose to be taken into cells where is used in respiration. Glucose is also converted to glycogen by liver and muscle which is stored in the liver and muscles  »» Levels of blood sugar lowers  »» Blood sugar levels return to normal

Level of glucose decreases  »»  Brain sends message to the pancreas through neurones »» Pancreas releases glucagon  »» liver starts to break down stored glycogen and convert it back into glucose which can be used by cells »» Blood sugar levels raise »» Blood sugar levels return to normal

  c) Negative feedback is when there is a change in the normal behaviour of the body (a change in blood sugar levels in this case) and the body reverses these changes and make them return back to its set levels.
a) Diabetes type1
Causes: Body does not produce the right amount of insulin or, in some cases, does not produce any at all.
Treatment: Daily injections of insulin, managed diet, planned exercise to balance energy needs with food and insulin intakes.
Diabetes type 2
Causes: Pancreas does produce insulin but cells stop responding properly to the insulin.
Treatment: lose weight and eat a carefully balanced diet can often control or even reverse the illness. However for some people oral drugs and even injections of insulin may be needed.
c)  Genetic engineering involves the extraction of genes from one organism, or the synthesis of genes, in order to place them in another organism (of the same or another species) such that the receiving organism expresses the gene product.

Endocrine System Activity

Our Biology teacher, Magdalena Ravagnan, asked us to answer the following questions which have to do with the topic we are now studying in class, Endocrine system.

1)Define Hormone
2)Search a picture which shows the glands which secrete hormones in the human body
3)a)State the effects of adrenaline
b)Choose a picture which shows a situation in which adrenaline is secreted. Explain

1)Hormones are chemical substances that help to regulate processes in the body

3) Effects:

  • It triggers the body’s fight-or-flight response
  • It prepares your body for a vigorous action.
  • Gives you more energy, your heart beats faster.
  • triggers the blood vessels to contract to re-direct blood toward major muscle groups, including the heart and lungs
  • The body’s ability to feel pain also decreases as a result of adrenaline,
  • noticeable increase in strength and performance, as well as heightened awareness, in stressful times.
  • adrenaline’s effect can last for up to an hour.



Diarrhoea and Choler

Our Biology teacher, Magda Ravagnan, asked us to watch a video about diarrhoea and cholera, and answer some questions following it.


1) Name signs/symptoms caused by cholera.





2) State ways in which the bacterium spreads in the village.

Defecating near the river, therefore contaminating the water

Having dirty hands, not cleaning them, and touching other things/people.

Flies transport the bacterium to things we consume or touch.

3) What is diarrhoea?

A condition in which faeces are discharged from the bowels frequently and in a liquid form.

4) How does the cholera bacterium cause diarrhoea?

Toxins from bacteria are produced, they attach to the villi which produce chloride in the lumen (where the food passes). Production of chloride increases, which means that the concentration of water decreases. So the water of blood goes to the lumen, from low concentration to high. Which is why when you have diarrhoea you become so dehydrated.

5) How did the boy treated his father?

He went to a doctor in the village and she said to boil the water and add tablespoon of salt and sugar.

You can also treat it with antibiotics.

6) Name the different actions which the boy taught to the people in the village to prevent the disease.

He told the villagers to wash their hands after pooing or peeing, after touching a lot of germs and before eating. Also to make sure the water is drinkable (by adding chlorine and waiting 30 minutes) and cooking the foods you eat. Finally to put a net to protect food and drinks from mosquitoes and flies.

Characteristics of Living Organisms

Our biology teacher, Male Ravagnan, asked us to write a blogpost following her instructions.

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On the first picture you can see a grandmothers and babys hand. I chose because you can see a clear example of GROWTH which is the permanent increase in size and dry mass by an increase in number of cells, cell size, or both. On the second picture you can see a cheetah running at a very high speed. You can see MOVEMENT which is an action by an organism or part of an organism that changes position or place.

1. Nutrition:

Taking in nutrients which are organic substances and mineral ions, containing raw materials and energy for growth and tissue repair, absorbing and assimilating them.

2. Excretion:

Removal from organisms of toxic materials, the waste products of metabolism and substances in excess.

3. Respiration:

Chemical reactions that break down nutrient molecules in living cells to release energy.

4. Sensitivity:

The ability to detect or sense changes in the environment and to make responses.

5. Reproduction:

Progresses that make more of the same kind of organism.

6. Growth:

The permanent increase in size and dry mass by an increase in number of cells, cell size, or both.

7. Movement:

An action by an organism or part of an organism that changes position or place.