B1 - Cell Biology Flashcards
Define Prokaryotic organisms.
Small, simple celled organisms.
Define Eukaryotic organisms.
Complex celled organisms.
Give an example of Eukaryotic cells.
Animal or Plant cells.
Give an example of Prokaryotic cells.
Bacteria.
Name the 5 parts of an animal cell.
- Nucleus
- Cytoplasm
- Cell membrane
- Mitochondria
- Ribosomes
The plant cell has all the parts of the animal cell plus three extra. Name those extra three parts.
- Cell wall
- Permanent vacuole
- Chloroplasts
What five parts don’t Bacteria cells have that plant cells do.
- Ribosomes
- Mitochondria
- Chloroplasts
- Vacuole
- Nucleus
Bacterial cells don’t have a “true” nucleus - instead they have a …
single circular strand of DNA that floats freely in the cytoplasm.
What might bacterial cells also contain?
Plasmids.
What is the purpose of a microscope?
To help us see what we cannot see with the naked-eye.
Light microscopes use…
Light and lenses to form an image of a specimen and magnify it.
Electron microscopes use…
Electrons instead of light to form an image with higher magnification than light microscopes.
What is “higher resolution”?
The ability to distinguish between two points and give a sharper image.
What is the importance of electron microscopes?
To see smaller things in more detail like the internal structure of mitochondria.
What is the formula for Magnification?
Magnification = Image size / real size
What is differentiation?
The process by which a cell changes to become specialised for its job.
What happens as a cell changes?
They develop different subcellular structures and turn into different types of cells, allowing them to carry out specific functions.
What are the cells that differentiate in mature animals mainly used for?
Repairing and replacing cells such as skin or blood cells.
What are the five required examples of specialised cells and their specialisations?
- Sperm cells (reproduction)
- Nerve cells (rapid signalling)
- Muscle cells (contraction)
- Root hair cells (absorbing water and minerals)
- Phloem and Xylem cells (transporting substances)
How does the nucleus contain the genetic material of someone?
In the form of chromosomes.
What are chromosomes?
Coiled up lengths of DNA molecules.
What does each chromosome carry?
A large number of genes.
What do genes in chromosomes do?
Different genes control the development of different characteristics.
How many chromosomes are in the human cell?
46 (23 pairs).
What is the purpose of the cell cycle?
To make new cells for growth, development and repair.
____ _____ in ______________ organisms ______ to produce new _____ as part of a series of stages called the ____ ______. (To do with the cell cycle!)
BODY CELLS in MULTICELLULAR organisms DIVIDE to produce new CELLS as part of a series of stages called the CELL CYCLE.
The stage of the cell cycle when the cell divides is called…
Mitosis.
Why do multicellular organisms use mitosis.
To grow or replace cells that have been damaged.
How is the DNA spread out in a cell that is not dividing in the cell cycle?
In long strings.
Before it divides, what does the cell have to grow and increase the amount of?
Subcellular structures such as mitochondria and ribosomes.
What forms around each of the sets of chromosomes during Mitosis?
Membranes form around each of the sets.
Are stem cells differentiated or undifferentiated?
Undifferentiated.
What is the importance around Embryonic Stem Cells?
They can turn into any type of cell.
Undifferentiated cells, called stem cells, can…
examples of what they can do
- Divide to produce lots more undifferentiated cells.
- Differentiate into different types of cells, depending on what instructions they’re given.
- Differentiate into specialised cells to use in medicine or research.
Where are stem cells found?
In early human embryos.
Where are adult stem cells found?
Bone marrow.
What can adult stem cells turn into?
Certain things such as blood cells.
What can stem cells in a lab be grown to produce…
Clones.
