Archivo de la etiqueta: IGCSE Biology

Human Nutrition

After dedicating 2 lab classes to complete activities 1 and 2 , we had to make a cartoon that represented the alimentary canal in proteins , fats and carbohydrates,  in our group base (Fermin Lucia and I)

1) 

2) a) First I see the food, and the salivary glands start working by secreting saliva.

b) Secondly, I ingest the food and start biting and breaking the food into smaller pieces with my teeth.

c) Then, with the help of the saliva, the food softens and the food becomes a bolus.

d) Then, I  gather a lot of saliva in my mouth, and I push the bolus backwards woth my tongue

e) Finally, I swallow all the saliva, that pushes the bolus through the oesofagus, to get to the stomach.

3) 

Self evaluation

We found it difficult to understand what a cartoon was and should be. Moreover, we couldn’t organize ourselves in an effective way at first. After thinking about it, we decided to divide the work. Fermin told me what to draw, I drew  and looked up the information and Lucia painted all the comics and helped me to draw. This was amazing, because we all worked in an equal way as a team !

Variation – Chapter 19

Today in Biology , Ceci gave us the task of answering the following questions, I worked with Renata Marty.

19.1 ) Decide wether each of these features shows continuous variation or discontinuous variation.

a)  Blood group in humans / discontinuous variation

b) Foot size in humans  / Continuous variation

c) Leaf lenght in a species of tree /  Continuous variation

d) Presence of horns in a cattle / Discontinuous variation

19.3 ) The photograph shows a small mammal called a tarsier. Tarsiers feed on insects, which they hunt at night.

How is the tarsier adapted for survival environment?

First of all, as his skin colour is somehow similar to the color of the trees, he can easily camuflage and so he can not be seen by predators. Secondly, his hands are perfect to climb trees, as he has 4 legs and his fingers perfectly match each other.

 

 

Seed Germination

In Biology class, after revising seed germination  we had to answer the two questions of the activity 3 of page 210

i) The age of seeds to make a fair test, if not you would not know if the results are different because of the age of the seed or because of the different conditions.

ii) Room temperature and the presence of water.

Then, we had to make this test on seed germination with Nina we got 10/10

Here you can take the test too

Asexual and Sexual Reproduction

There are 2 types of reproduction (in which a new organism gets chromosomes from its parent/ parents which contain a set of instructions called GENES)  called Asexual reproduction and Sexual reproduction.

Asexual Reproduction

• It involves ONE parent, whose organism cells divide by Mitosis, the divisions create a new set of cells which conform an organism which will be EXACTLY THE SAME

Example: Potatoes

• They reproduce using stem tubers, the tubers are planted underground, where many new plants will grow as whenever there is a bud a new plant can grow

Sexual Reproduction

1st the organism produces GAMETES, sperm in case of male and eggs in case of female.

2nd The two gametes join their nuclei and fuse together to create a new cell called ZYGOTE. (This process is called fertilization)

The zygote

-It divides again and again and becomes an organism with a combination of genes from both parents, so the offspring is different from all the other organisms , even their parent’s one

Gametes

– They are made of the division of ordinary cells called MEIOSIS. As they are an ordinary cell divided, they do not have 46 chromosomes as normal, they have 23 as when the two gametes join they can create a cell with the common number of chromosomes.

Cells are divided into :

– Haploid Cells -> Cells with 23 chromosomes

-Diploid Cells -> Cells with 46 chromosomes