Biology - Cells Flashcards
What are all living things made up of?
Cells
What are cells?
Cells are the smallest units of living matter that exhibits the characteristics of life
What is everything in a cell called?
Organelles
What is the function of the cell membrane?
Controls what enters and leaves the cell
What is the function of the cytoplasm?
A jelly-like fluid in which foods, minerals and salts are dissolved
What’s the function of the nucleus?
It’s the brain, it controls the cells activities
What is the function of the vacuoles
It stores food, water and waste
What’s the function of the chloroplasts?
It contains chlorophyll which traps sunlight to make food (photosynthesis)
What is the function of a cell wall?
It gives shape and support
Give 4 differences between a plant cell and an animal cell
animal - no cell wall plant - cell wall animal - no chloroplasts plant - chloroplasts animal - irregular shape plant - regular shape animal - small, temporary vacuoles plant - large, permanent vacuoles
What’s the function of the eye piece?
Look through to see image
What is the function of the objective lens?
It magnifies the image
What is the function of the stage?
Where the glass slide is placed
What is the function of the focus knob?
It moves the objective lens up or down to see image more clearly
What is the function of muscle cells?
It allows movement
What is the function of nerve cells?
It carries messages
What is the function of white blood cells?
It defends against diseases
What is the function of red blood cells?
It carries oxygen
What is a tissue and give an example of one
A group of similar cells with a special function eg, muscle
What is an organ and give an example
It’s a group of different tissues that work together to carry out special functions eg, the heart
What is a system and give an example
It’s a group of organs working together eg, the digestive system
To examine onion bulb cells (plant) [experiment]
1- Using a forceps, pull a small piece of onion from the inside of the onion
2- Using a dropper, add 3 drops of water on a slide. Place the onion tissue flat on the water
3- Gently lower a cover slip onto a slide
4- Apply the iodine stain to the slide alongside the coverslip
5- Place some filter paper on the other side of the coverslip to draw the iodine across the cells
6- Examine the onion cells under low, medium and high power
7- Make a sketch of the onion cells at high power
Results - A clear image is seen of the cell wall, vacuole and nucleus. The Iodine stains the nucleus an orange/yellow colour.
Conclusion - The microscope can be used to see plant cells magnified.
