cells Flashcards
what are cells?
cells are the basic unit of life, chemical reactions take place in the cell to keep the organism alive, cells can carry out basic life process like reproduction and respiration
what type of organism are there?
- multicellular ( humans, animals )
- unicellular ( yeast, amoeba, and bacteria )
what are unicellular organisms?
unicellular organisms are only made up of 1 cell
what are multicellular organism?
multicellular organism is made up of many different types of cells. They come in different sizes, different shapes and they perform different functions. The cells have similar characteristics
What are the two type of microscopes?
- light microscopes
- electron microscopes
characteristics of microscopes:
- light microscopes
provide relatively low resolution when it is enough, used to stud living cells - electron microscopes
provide higher resolution images and higher magnification, cannot be used to study living cells ( protoplasm and some organelles like mitochondria and ribosomes are able to seen through the electron microscopes )
what is protoplasm?
protoplasm is a living material that can bel found in every living cell. It is a jelly-like substance which consist of cytoplasm, nucleus and cell membrane. Protoplasm can be studied through both light and electron microscope
definition of nucleus.
Nucleus:
1. controls all cell activities taking place in the cell
2. contains deoxyribonucleic acid ( DNA ) which is passed down from parents to offspring
3. nucleus is essential for cell division
definition of cytoplasm.
cytoplasm:
1. cytoplasm is a jelly-like substance
2. the site where most of the chemical reactions take place in the cell
3. contains organelles which are membrane bound specialized structure which performs specific functions
definition of cell membrane.
cell membrane:
1. partially permeable ( only allow certain substances to pass through )
2. controls the movement of substances in and out of the cell
3. also known as plasma membrane
definition of chloroplast.
chloroplast:
1. chloroplast can be found in the cytoplasm of plant cells
2. contains a green pigment ( chlorophyll )
3. traps light to photosynthesize
definition of cell wall.
cell wall:
1. cell wall is full permeable ( allows all substances to pass through )
2. only found in plant cell
3. helps to support the cell by giving it a regular shape
4. protects the cell from injury
5. made up cellulose
definition of vacuole.
vacuole:
1. has high water content
2. stores water, nutrients and mineral salts
plant cell = one central vacuole
animal cell = many small vacuole
mitochondrion ( singular ) , mitochondria ( plural )
performs aerobic function which breaks down glucose to release energy
ribosomes
1.attached to the membrane or freely
2.synthesize proteins for the cell
definition of differentiation
differentiation is the process where a cell becomes specialized for a specific function
What are some examples of specialized cell?
- red blood cell
- root hair cell
definition of red blood cell.
A red blood cell:
1. contains hemoglobin which transport oxygen from the lungs to all
parts of the body
2. does not have a nucleus which enables the red blood cell to store more hemoglobin for transport of oxygen
3. has biconcave shape ( thinner central portal ) which increases surface area for oxygen to diffuse in and out efficiently
definition of a root hair cell.
A root hair cell:
1. absorbs water and mineral salts
2. has a long and narrow protrusion which increases surface area to absorb water and mineral salts quickly
( cell membrane enable its function, as the cell membrane controls the movement of substances in and out of the cell )
definition of tissue.
A tissue is a group of cells with similar structures work together to perform a specific function called tissue
types of tissue.
- simple tissue
makes up of the same types of cell - complex tissue
made up of different types of cells
definition of organ
An organ is a group of tissues that work together to perform a specific function
definition of organ system.
An organ system is a group of organs which work together to perform a specific function
Organs work together to form systems
definition of an organism.
systems work together to form an organism
why is division of labor important? Give an example using the root hair cell.
Cell division is important as it allows the organism to function effectively and efficiently. The root cell is able to absorb water an mineral salts due to its cell wall. The cell wall controls the movement of substances in and out of the cell. While the cell’s cell wall supports the cell and gives it a regular shape to prevent it from bursting
how many parts are there to a microscope and state them.
There are 10 parts.
1.eye piece
2.objective lenses
3.nose piece
4.stage
5.stage clip
6.condenser
7.light source
8. arm and the base
9. fine adjusting knob
10. coarse adjusting knob
state the function of the eyepiece and objective lenses
The eye piece and objective lenses magnifies the image of the specimen
state the function of the nosepiece
The nosepiece helps to move the objective lenses with different magnifying power to focus on the image
state the function of the stage and stage clip
The stage clip helps to hold the slide in place while the stage is where the specimen is placed at
state the function of the condenser and the light source
The condenser is mounted directly below the stage which helps to focus a beam of light onto the specimen while the light source helps to illuminate the specimen evenly
State the function of the arm and the base
The arm and the base helps to hold all parts of the microscope together
