Topic 2 (Cell Division And Growth) Flashcards
What’s is cell differentiation?
The process , by which a cell changes to become specialised for its job. Having specialised cells allow multicellular organisms to work more efficiently
How does cell division happen?
By mitosis
What is cell elongation in plants?
It is where the plants are expand making so bigger and so making the plant grow
Where the cell division in plants happen?
It happens in tips of shoots and roots in areas called meristems
What is the cause of cancer?
Uncontrolled cell division.
The rate at which cells divide by mitosis is controlled by the genes, however if there is a change in one of the genes that control cell division it may start to divide uncontrollably which results in a mass of abnormal cells called tumour. If a tumour invasion destroy surrounding tissue can be called cancer.
What’s the percentile charts used for?
There used to assess a child’s growth over time. A babies growth is monitored after birth to make sure it’s normally the measurements taken the length of the mass and the head circumference.
If a three month old weighs 7 kg and is just above 75%, how does he fit within the gross chat?
roughly 75% three months old are lighter than him and 25% are heavier than him
What’s the undifferentiated cells called?
They’re called stem cells
Where can stem cells be found?
There are found an early human embryos and they can divide into any type of cell, so embryonic stem cells are used for growth and development. They’re also found adults in the bone marrow but can only produce blood cells and new skin cells, so adult stem cells are used to replace damage cells.
Stem cells in plants
Meristem produce unspecialised cells that are able to divide and form any type of cell. They act like embryonic stem cells but unlike human cells they can divide and differentiate to generate any type of self for as long as the plant lives.
Uses of stem cells in medicine
Adult stem cells are used to cure some diseases, e.g. sickle cell anaemia can be cured with bone marrow transplant.
Embryonic stem cells can be stimulated to differentiate into specialised cells which are needed to replace those that have been damaged by disease or injury such as new cardiac muscle cells can be transplanted.
What are the risks of using embryonic stem cells?
Tumour development as stem cells divide very quickly and if scientists are unable to control the rates of the cells division then a tumour can be developed.
Disease transmission as viruses live inside cells and if the donor stem cells are affected with a virus it can be passed on to the recipient and so make them sicker.
Rejection the patient’s body may not recognise the cells and so it could trigger an immune response to try and get rid of them so the patient has to take drugs to suppress this response which makes them susceptible to diseases.
There are also ethical issues of using embryonic stem cells as people argue that it ruin potential human life, others think that patients who are suffering are more important then potential life
