Archivos de la categoría biology

Lab experiment: Growing Bacteria

August 23rd

Describe what we did last class (Wednesday) and the results today

You may add drawings or photos to be clearer

 

Last class we preapered flavourless jelly without cooling it to make it solid. Then, we decided that we wanted to watch bacteria reproduction, and as flavourless jelly is transparent and of an interesting solidity it was a nice thing to test it on.

To do this we had to choose between coughing on our hands, or touching dirty things such as the floor. We chose to cough and then we put our finger on the non-solid-yet jelly. All this we did on a petri dish which are used to grow bacteria.

Today, after 1 week we went to the lab to see the result of our bacteria growth. Our dish isn’t so dirty, so we can guess that one week ago our mouth was quite clean from bacteria. Instead, the people that chose to touch the floor got more disgusting results. Here is ours:

 

Seed germination- Biology project

  1. On July the 5th, we prepared a flask with soaked lentils, cotton and blotting paper to make the seeds germinate. In my case, as I didn’t had a flask that day, I started the project by myself on Mar Del Sur the 22nd of July.

We worked in pairs, in my case, with Lucas Alonso Breuer studying variables (temperature, water, sunlight and oxygen).

The variable we studied was with sunlight, so Lucas protected his flask from sunlight, but he made a mistake and give it artificial light, which we later found out that also helps for photosynthesis. Also we couldn’t compare perfectly our results as I by mistake put in another temperature than him, more info below (;.

Besides of starting a couple of weeks later, I actually had more difficulties than that one. In MDS, the temperature was very cold, which I did most definitely not expect, so I didn’t know when to water it or were to leave it. After fighting for 3 days with the seeds, the 4th day they germinated.Pitifully, they died on day 7 because of the cold (I suppose). After seeing this, I accidentally dropped the flask and couldn’t take a proper picture

Asexual and sexual reproduction

Reproduction

Reproduction is one of the fundamental characteristics of all living things. Each kind of organism, has a certain way to reproduce but all of the methods are divided in sexual reproduction and asexual reproduction. In reproduction, each organism gets a set of chromosomes from their parents. Chromosomes are a set of DNA which is in contained in the nucleus, and contains a set of instructions called genes.

Asexual Reproduction

  • Just one parent
  • A cell divides and creates two new cells
  • As it is one parent, the genes keep the same, producing the new cells to look exactly the same to their parents

Example: Potato reproduction

Potatoes reproduce by using stem tubers. Some tubers grow above the surface and grow leaves, which photosynthesizes. Others, grow underground, and swelling form on them. This swellings are provided with sucrose which comes from the leaves. Then, the sucrose is converted to starch and stored, creating potatoes. This is why they are a great source of starch. Also, each plant can produce many stem tubers.

Sexual Reproduction

In sexual reproduction, the parents organisms produce sex cells called gametes, an example of this are sperm (male gamete) and eggs (female gamete). When this two gametes join and their nuclei fuse, it is called fertilisation. When this happens, a new cell is created, called zygote. The zygote divides repeatedly and ends up creating an organism which has chromosomes and genes from both parents.

Gametes are not like every cell. Gametes contain only half as many chromosomes as normal cells, so when gametes fuse, the zygote will have the normal amount of chromosomes (46)

 

Classification

Today we worked with quizlet to learn about classification, and prove ourselfs

https://quizlet.com/subject/Classification/

Words (biological meaning) now I know the meaning of:

 

Domain: Higher biological rank

http://www.biology-online.org/

Then I did an IGCSE test on quizlet

https://quizlet.com/102276024/igcse-biology-classification-chapter-1-flash-cards/

I got a 75%!

Then I did a gravity game!

https://quizlet.com/102276024/gravity

 

Biology Test with Bautista Bravo

Name:………………………………….

 

Date:…../……./…….

Colegio Las Cumbres

Biology test

For senior 1

 

Hi guys! Before you start the test, I recommend you to  read all the instructions and questions. Wish you luck!

 

  1. What are we made of?

……………………………………………………………………………………………………………………………………………………………………………………………………

2)  Label this cell

Resultado de imagen para label this cell

3) What type of cells do human beings have?

………………………………………………………………………………………………………………………………………………………….………………………………………..

4) Do cells reproduce?

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5) Do cells have a gender?

………………………………

6) Draw a animal cell

 

7) Are cells alive? Yes/No

 

8)Elaborate what you know about cells

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9) What’s the function of the cell membrane?

……………………………………………………………………………………………………….

10) Order from smaller to big. Organell-Cells-Tissue-Organ system-Organism