Theme 5 Toni Cells Flashcards
Multi potent meaning
Having the ability of self-renewal and developing into multiple specialised cell types present in a particular tissue or organ.
Pluripotent meaning
A cell that is able to develop into many different types of cells or tissues in the body.
Totipotent meaning
Single cells that can give rise to a new organism
What are stem cells?
Undifferentiated cells that can give rise to many more cells of the same type and from which specialised cella such as nerve cells or muscle cells.
Differentiation meaning
The process of a cell becoming adapted to carry out a specific function
Embryonic stem cells
What stage are they found in?
What can they differentiate into?
Blastocyst stage (3-5 days old)
Any cells
Adult stem cells info
Few cells which can differentiate even when fully developed
Bone marrow stem cells give rise to blood cells
Use of stem cells
Cloned to treat and cure diseases of the blood such as lymphoma and leukaemia
For research
Therapeutic cloning
A process that creates embryonic stem cells with the same DNA as a donor cell, for use in disease research and treatment
Issues around the use of stem cells
Ethical/religious reasons. E.g. disagree with the use of embryonic stem cells as they have the potential to become a human life
Advantages of adult stem cells
Less likely to be rejected when transferred to a patient
No major ethical concerns
Evidence of success
Adult stem cell disadvantages
Limited differentiation potential
Cannot be grown on mass scale
Bone marrow donations are painful
Embryonic stem cell advantages
Can differentiate into almost any cell type
Can be grown and maintained in cultures for a year of more than
Can be studied to learn about the process of development
Embryonic stem cells disadvantages
Cells may be rejected
An embryo is destroyed to obtain the cells
Rapid cell division can lead to cancer or tumors
Cell theory 3 principles
All living things are made of 1 or more cell/s
Cells are the most basic unit of structure and function in all living things
All cells are created by pre existing cells
Eukaryote cells info
Has a nucleus
Larger than prokaryotic cells
Cell division by mitosis
Paired diploid chromosomes
Prokaryotic cells info
No nucleus
Smaller then eukaryotic cells reproduce sexually and asexually
Cell division by binary fission
Circular DNA (plasma)
Unicellular
Erythrocytes (red blood cells) function and features
Carries oxygen around the body by using haemoglobin.
Has no nucleus to increase the surface area,
Biconcave shape allowing more efficient oxygen diffusion,
Elastic plasma membrane allows the cell to change shape to fit through small capillaries
Neurones (nerve cell) functions
Sensory neurones conduct…
Motor neurones conduct…
Conduct electrical impulses in the nervous system.
Sensory neurones conduct impulses towards the central nervous system. (CNS)
Motor neurones conduct impulses away from CNS
Squamous epithelial cells features
Flattened cells, suited to exchange surfaces
Supported by a basement membrane, thin layer of protein fibres and polysaccharides supporting the epithelium
Ova (egg cell) features and functions
Larger than sperm cells because after fertilisation the zygote needs to divide several times.
Ovarian follicle cells and gel layer protects the ovum
Striated muscle cells function and features
Multiple nuclei making protein synthesis more efficient
Contracts which mores the bones in the body and allows movement
Length of the cell allows them to contain protein needed for muscle contractions
Differentiation meaning
Cells becoming specialised
Undifferentiated cells meaning
Cells that are not specialised
What does gene expression do
Causes the cell to know what it needs to specialise as
Totipotent stem cells
They can divide to produce any type of body cell for only a limited time in early mammalian embryos
Pluripotent stem cells can become…
Used in…
Can cause (negative)…..
Can become almost any cell
Used in research to treat human disorders
Cause tumours
Ethical views on pluripotent stem cells
Killing an embryo that had the chance to become a human
Saving lives with an embryo
Multipotent and unipotent stem cells
Found in…
Can differentiate into. …
Found in mature mammals
Multi can differentiate into a limited number of cells
Uni can differentiate into one type of cell such as muscle cells.
Endoderm examples
Lungs
Liver
Pancreas
Small and large intestines
Mesoderm examples
Heart
Bone
Inner lining of. Skin
Muscles
Kidneys
Bladder
Sex organs
Ectoderm examples
Sweat glands
Hair
Outer layer of skin
Nervous system
Sources of stem cells
Embryos
Umbilical cord blood
Placenta
Adult stem cells
What is haematopoiesis?
Where is it found?
The process of stem cells developing into specialised blood cells
Bone marrow of adults
What is mitosis
A process where a cell divides into two identical daughter cells
4 stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
What are the 3 stages of a cell cycle
Interphase
Mitosis
Cytokinesis
What is happening in G1 interphase
Cellular contents excluding chromosomes duplicate
What happens in G0 of interphase
Cells do their function
What happens in s (synthesis) of interphase
The chromosomes are duplicated
What happens in G2 of interphase
Cell is double checked before cell goes through mitosis so there is no error that could cause cancer
What happens in prophase of mitosis
Chromosomes become visible and the nuclear envelope disappears
What happens in metaphase of mitosis
The chromosomes arrange themselves at the centre of the cell
What happens in anaphase of mitosis
Each of the two threads of chromosomes migrates to opposite poles
What happens in telophase of mitosis
The nuclear envelope reforms to produce two daughter cells
What happens in cytokinesis of the cell cycle
The cytoplasm divides to separate the 2 daughter cells
Calculation for calculating magnification
Size of image divided by the size of object
What are induced pluripotent cells?
Turning multipotent cells into pluripotent cells
What is erythropoiesis?
Stem cells differentiating into red blood cells
