Cell Biology Flashcards
What are animal and plant cells?
Eukaryotic cells
What’s the purpose of a cell membrane?
It is a protective barr around the outside of the cell. It controls which substances can pass in and out of the cell.
What is the purpose of the nucleus
It contains genetic material/DNA of the cell, and so controls what the cell does
What is the purpose of the cytoplasm
Its a gel like substance containing nutrients and salts where the chemical reactions take place
What’s the job of the mitochondria
They carry out aerobic respiration. It provides cells with the energy they need to function to use in chemical reactions (they break down sugars (eg. Glucose)
What do ribosomes do?
It’s where protein is made
What are bacteria cells
Prokaryotic cells “unicellular = 1 cell” (much smaller in comparison to plant and animal cells)
What is the use of a circular strand of DNA/nucleoid/circular chromosome?
it’s contains the genes they need to survive and reproduce. (The genetic material is not enclosed in a nucleus)
The use of plasmids?
They carry extra genes like antibiotic resistance (not needed on a daily basis but may come in handy)
What is flagella?
It helps propel the bacteria (allows the bacteria to move)
What is the cell wall made out of and what does it do?
The cell wall is made out of cellulose. It makes it stronger and allows it to maintain the shape of the cell.
What do plant and algal cells have in common? What does it help with?
They both have a cell wall made of cellulose which strengthens the cell
How does a chloroplast function?
It’s an organelle that contains the green pigment (chlorophyll) and it contains the enzymes needed for photosynthesis. It absorbs light energy for photosynthesis
What is the purpose of the permanent vacuole?
It’s filled with a solution of salt, sugar and organic acids (cell sap). The permanent vacuole helps keep the cell strong and gives it shape (supports the cell membrane - the thin skin around the cell) it also controls what passes in and out of the cell.
What is a cell?
A cell is the smallest unit of life that can live on it own. Cells make up all living organisms and their tissues.
What is enclosed within the nucleus for eukaryotic cells?
Cell membrane
Cytoplasm
Genetic material
what is the formula for magnification?
Magnification = image size/real size
real size = image size/magnification
image size = magnification x real size
What does the nucleus of a cell contain?
It contains chromosomes made of DNA molecules.
What do each chromosome carry
Each chromosome carries a large number of genes (Different genes control different characteristics. Eg. hair, eyes)
How do cells divide
They divide in a series of stages called the cell cycle.
What are chromosomes normally found in
In the body cells the chromosomes are normally found in pairs
Describe the stages of the cell cycle including mitosis
The genetic material is doubled and then divided into two identical cells before a cell can divide it needs to go and increase the number of sub-cellular structures such as ribosomes and mitochondria the DNA replicates to form two copies of each chromosome.
In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides.
Lastly the cytoplasm and the sun membrane divides to form two identical cells.
Why is cell division by mitosis important
Cell division by mitosis is important in the growth and development of multicellular organisms
How many chromosomes does a human cell have
23 pairs of chromosomes
Why do multicellular organisms use mitosis
To grow or replace cells that have been damaged
What’s the importance of cell differentiation
It allows the cell to specialize and perform specific functions in the organism
What type of specialization can animals cells carry out to function?
Sperm cells
nerve cells
muscle cells
What type of specialization can plant cells carry out to function?
Root hair cells
Xylem
Phloem
As an organism develops what happens to the Cell
The cell differentiate to form different types of cells
Most types of animal cells differentiate at an…
early stage
Many types of plant cells retain the ability to…
Differentiate throughout life
Stem cells are called?
Undifferentiated cells of an organism (not specialized)
why are electron microscopes at an advantage?
Electron microscopes have a much greater magnification and resolution then light microscopes.
How can having a higher magnification and resolution power benefit when studying cells?
It can be used to study cells in much finer detail and it allows biologists to see and understand many subcellular structures.
Explain how microscope techniques have developed over the time?
Improvements in lens manufacture help to solve problems like color and image resolution
Mature animals cell division is mainly restricted to what?
Repair and replacement
For cells to differentiate what do they need to become
They require different subcellular structures to enable to carry out a certain function (They become specialized cells)
What is the job of a sperm cell
Is to join with the ovum (egg cell) (Fertilization) 
What happens to the ovum and the sperm cell during fertilization
There Genetic information is combined
What’s the purpose of enzymes in a sperm cell
Allows them to digest their way through the outer layer of the ovum 
What’s the purpose of a nerve cell
Body sends electric impulses around the Body
What’s the purpose of an axon in the nerve cell
It carries the electric impulses from one part of the body to another
What are the axons covered in? do what do they help with?
Myelin. It helps speed up the transmission of the nerve impulse
What are synapses for the nerve cell
The end of the axon has synapse. synapse allow the impulses to pass from one nerve cell to another
What do dendrites do for the nerve cell
They increase the surface area so that other nerve cells can connect more easily
What do muscle cells contain
They contain protein fibers which can change the length
What do muscle cells form when they work together
Muscle tissue