شرح ساينس الصف الرابع الابتدائي لغات - الفصل الدراسي الأول
شرح ساينس رابعة ابتدائي - ترم أول

لينك تحميل الملزمة
https://drive.google.com/file/d/1mqY-OijFkAB5R1NNH1z0mCAEb6fh3R6i/view?usp=sharing

لينك تليجرام
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لينك واتس اب
This Lesson:
In 1665, Robert Hooke used his microscope to observe the tiny particles of some samples of plant parts that cannot be seen by naked eye, and he named each of these tiny particles "the cell ".
▌Robert Hooke was the first person who use the word "cell"

Importance of microscopes:
• The modern microscopes help scientists to make new discoveries, such as :
- The cell is the building unit of living organisms bodies.
-All living organisms are made up of cells however these cells are large or small.
- The body of some simple living organisms consists of one cell only.
- The body of living organisms that contains complex systems consists of many
different cells.
- The different parts of the cell and their functions.
- The nucleus that is found inside many cells .

Structure of microscope:
The microscope consists of many parts as shown in the figure below:

Preparing a slide of plant cells:
Tools

Using the microscope to examine the slide :
Steps
1. Put the slide on the stage and fix it with the stage clip.
2. Choose the suitable objective lens and look through the eyepiece.
3. Rotate the coarse focus and the fine focus to see a clear image for the sample on the slide.
4. Replace the slide of plant cells with a prepared slide of animal cells.

Observations:
The shape of the plant cells differs from that of the animal cells .


The samples appear more clearly when using the "high power objective lens".

بالتوفيق
مستر احمد الباشا