By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth. There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. This is why scientists cannot be certain about how life began.
Isolation. Is best to break infection
Turn the revolving turret (2) so that the lowest power objective lens (eg. 4x) is clicked into position.
Place the microscope slide on the stage (6) and fasten it with the stage clips.
Look at the objective lens (3) and the stage from the side and turn the focus knob (4) so the stage moves upward. Move it up as far as it will go without letting the objective touch the coverslip.
Look through the eyepiece (1) and move the focus knob until the image comes into focus.
Adjust the condenser (7) and light intensity for the greatest amount of light.
Move the microscope slide around until the sample is in the centre of the field of view (what you see).
Use the focus knob (4) to place the sample into focus and readjust the condenser (7) and light intensity for the clearest image (with low power objectives you might need to reduce the light intensity or shut the condenser).
When you have a clear image of your sample with the lowest power objective, you can change to the next objective lenses. You might need to readjust the sample into focus and/or readjust the condenser and light intensity. If you cannot focus on your specimen, repeat steps 3 through 5 with the higher power objective lens in place. Do not let the objective lens touch the slide!
When finished, lower the stage, click the low power lens into position and remove the slide.
Your microscope slide should be prepared with a coverslip over the sample to protect the objective lenses if they touch the slide.
Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses.
Always keep your microscope covered when not in use.
Always carry a microscope with both hands. Grasp the arm with one hand and place the other hand under the base for support.
The bands of circular muscle structures that are located at the cuttlefish skin are most likely responsible for the changes of its outer covering. In addition, the colour cells that are present on the cuttlefish skin were estimated to be about 10 million which is why it was coined "the chameleons of the sea."
Answer;
-Zygote
When sperm and ovum unite at conception, a zygote results.
Explanation;
-Conception occurs when a sperm cell from a fertile man swims up through the vagina and into the uterus of a woman and joins with the woman's egg cell (ovum) as it travels down one of the Fallopian tubes from the ovary to the uterus.
-A zygote is the union of the sperm cell and the ovum. Also known as a fertilized ovum, the zygote begins as a single cell but divides rapidly in the days following fertilization. After this two-week period of cell division, the zygote eventually becomes an embryo.
