Differentiation in Specialised Cells / Stem Cells Flashcards
What are Specialised Cells?
Specialised cells have a specific role in the body. To help them fulfil that role, they have a specific shape or structure. They have specific amounts of different organelles.
The role of a sperm cell is to deliver genetic material to an egg in order to fertilise it. How is the cell adapted to fulfil its role?
In its nucleus, a sperm cell has only half as much genetic material as a normal adult cell, which is important because it has to combine with the egg’s genetic material to form a normal cell’s worth.
It also has a flagellum on the end, which acts as a tail and allows the sperm cell to swim through the uterus and fallopian tube to reach the egg. The overall cell is also streamlined to help it swim along.
They also have lots of mitochondria, which provide the energy required for swimming.
At the front, sperm cells have lots of digestive enzymes which are used to break a hole into the egg when the sperm reaches it.
What is differentiation?
The process by which a cell changes to become specialised.
Certain cells are able to repeatedly divide by mitosis and differentiate into different types of specialised cells. What are these types of cells called?
Stem Cells
Where are plant stem cells found?
Meristems
Areas of the plant that are continually growing.
Where are early stem cells found?
Human Embryos
Where do adults contain stem cells?
Bone Marrow
However, unlike embryonic stem cells, they cannot turn into any type of cell, only certain ones such as blood cells.
How can you replace faulty blood cells in a patient using adult stem cells?
Stem cells transferred from the bone marrow of a healthy person can replace faulty blood cells in the patient who receives them.
How can embryonic stem cells be used to replace faulty cells in sick people?
You could make insulin-producing cells for people with diabetes, nerve cells for people paralysed by spinal injuries, etc.
Some people are against stem cell research. What are some arguments for and against this?
Some people are against stem cell research because they feel that human embryos shouldn’t be used for experiments since each one is a human life or has the potential to be a human life.
Others think that curing patients who are suffering is more important than the rights of embryos.
One argument in favour of this point of view is that the embryos is used in the research are usually unwanted ones from fertility clinics, which, if they weren’t used for research, would probably just be destroyed. However, campaigners for the rights of embryos usually want this banned too.
These campaigners feel that scientists should concentrate more on finding and developing other sources of stem cells, so people could be helped without having to use embryos.
