Sex hormones and puberty

Sex hormones are responsible of the most dramatic changes that occur in the body. They control puberty, egg and sperm production, pregnancy, birth and lactation.

  1. Read the information about Puberty HERE.
  2. State the female and male hormones which are responsible for the development of the secondary sexual characteristics
  3. Build a comparison table between the changes that occur in male and female after puberty.
  4. Search in the internet and summarize the site of production and effects of the following sex hormones:

– FSH, LH, oestrogen, progesterone, oxytocine, Hcg, prolactine and testosterone.

5. The chart shows the ages at which the changes associated with puberty take place in boys and girls. Answer questions a, b, c, d and e.

(a) What is the most common age at which boys undergo the changes of puberty?

(b) If a girl had not started menstruation by the age of 15, would this be cause for concern?

(c) Which two features of puberty show the greatest range in the times at which they  occur.

 

(d) Is it unusual for a girl of 9 years to start her menstrual periods?

(e) On average, is it boys or girls who first show the onset of puberty?

 

Publicado en S4 Biology virtual period- 2018 | Deja un comentario

ENZYMES

Enzymes are proteins that act as biological catalysts.

Let´s learn more about enzymes.   Watch the video!

Make sure to understand the meaning of the following key words:

  • catalyst
  • substrate
  • product
  • chemical reaction
  • active site
  • denaturation
  • temperature
  • Ph
  • Line-graph –
  • Independent and dependent variables

Why temperature control matters?

Click HERE ! Read the information and play all the animations.

ENZYMES ARE SPECIFIC. Take a look at the slides below and build a comparison table about protease, lipase, catalase. amylase, maltase and carbohydrase. Include three columns: enzyme, substrate and products.

 

Publicado en Senior 3 Biology - 2018 | Deja un comentario

Biology virtual period: Reflex arcs

Read page 5 from HERE.

  • Act: Answer the interactive question and post a scrrenshot with the answers.
  • Film 2 examples which show reflex actions. (BE CAREFUL IN USING HOT OBJECTS! MIMICS ARE ACCEPTED!)

For each example, name the structures involved:

stimulis __  receptor __coordinator __effector __ response

?                     ?                        ?                          ?             ?

Publicado en S4 Biology virtual period- 2018 | Deja un comentario

The eye as a sense organ

STRUCTURE OF THE EYE

Study the structure and functions of the human eye HERE, and complete pages 9 and 10 from the booklet.

HOW WE SEE COLORS

Watch the video!

Booklet Act: COMPLETE questions 4 c and d on page 10.

 

PUPIL REFLEX

  • In pairs,  add a video which shows the pupil reflex in your eyes.
  • Using your reflex actions´knowledge , sketch the sequence of the pupil reflex. State the stimulus, receptors, coordinator, effector, effect, response and all the neurones involved.
  • What is the importance of this reflex?
  • Booklet act: COMPLETE questions 1 b and c on page 9.

ACCOMMODATION OR FOCUSING

  • Play this animation about focusing a close or distant object and answer the interactive questions.
  • Booklet act.: Answer questions 2 and 4 a and b.

PROBLEMS WITH VISION?

Let´s discuss about them HERE!

Connections between the nervous system and the eye as a sense organ.

Booklet act: Answer question 5 on page 10.

 

 

Publicado en Senior 4 Biology - 2018 | Deja un comentario

Biology virtual period: Nervous system: neurones and synapse

Let´s start a new topic!

All mammals have a CENTRAL NERVOUS SYSTEM and a PERIPHERAL NERVOUS SYSTEM. The CNS is made up of the brain and the spinal cord. The peripheral nervous system is made up of nerves and receptores.

The NEURONES are special cells which coordinate the messages travelling through the nervous system.

  1. ANATOMY OF A NEURONE: Watch THIS video!
  • Act: State how the structure of a neurone is related to the function.

2. TYPES OF NEURONES: Read “overiew of neurone structure and function   from HERE  .

  • Act: Make a labelled drawing of each of the three types of neurones, motor, sensory and relay, and state their functions.

3. SYNAPSE:

  • Act: Post a short video explaining synapse.
  • Act: Describe in your own words how nerve impulses are transmitted from neurone to neurone.
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Endocrine system: adrenaline and ADH

Let´s continue studying hormones…

  1. Study the effects of adrenaline and ADH after reading this link.

Act: a- Use bullet points to summarise the effects of adrenaline.

b- Describe 3 situations in which adrenaline is secreted. Post a picture to show the examples.

 

2. Draw a flow chart to show the effects of ADH:

– when there is TOO LITTLE WATER in the body.

– when there is MUCH WATER in the body.

 

3- Solve the quiz from this webpage. Take a screenshot and post it.

Good luck! 🙂

 

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S4 Biology virtual period: Endocrine system: hormones and their effects

  1. Read page 1 from THIS LINK

Act: Define the term hormone

 

2. Where are the endocrine glands?

     Read the descriptions of the glands and the hormones they produced here

Act: Build a table to summarise the  hormones  each gland produces. You should include in the columns:

– Endocrine gland, Where in the body and Hormone produced

in the lines: Pituitary, testis, ovary, pancreas, adrenal and thyroid.

 

3. Effects of insulin in the human body

   Last year you studied the effect of insulin and glucagon secreted by the pancreas.

Act: Draw a flow diagram to explain the importance of insulin in the control of glucose in blood.

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Excretion and kidneys

Let´s revise the meaning of homeostasis

 

1- Write down 2 excretory organs and the substances they excrete.

2- Structure of the kidney. Read here!

3- The nephron

Watch THIS animation to study the filtration and reabsorption.

Publicado en Senior 4 Biology - 2018 | Deja un comentario

Movement in and out of cells: diffusion, osmosis and active transport

Before we start… explain the meaning of the following terms:

– solution
– concentrated solution
– diluted solution
– distilled water

Quick introduction: watch the video!

Read page 3 from THIS WEBPAGE and play the animations.

Publicado en Senior 3 Biology - 2018, Uncategorized | Deja un comentario

Welcome Senior 4!

Hi everyone!

It’s our 2nd year in preparation for the IGCSE exam so one of our challenges will be about recycling what we studied in Senior 3. There are 3 main topics this year:

1- Human body
2- Plants
3- Living organisms and their environment

For each class you will be expected to bring last year textbook and the Booklet with exercises. Get your blog ready with the Biology category. All blog assignments should appear in the category and, as well as tests, will be posted in the class Calendar.

All the best for this year!

Publicado en DHsecundaria, Senior 4 Biology - 2018 | Deja un comentario