Cells Flashcards
What is differentiation?
The process by which a cell changes to become specialised for its job.
What can stem cells do?
They can divide to produce lots more undifferentiated cells or they can differentiate into different types of cell (depending on what instructions they are given)
Where do stem cells come from?
They come from embryos or, in adults, certain places like bone marrow.
What is the advantage to embryonic stem cells?
Unlike adult stem cells, embryonic stem cells can differentiate into any cell.
What are stem cells used for?
Bone marrow stem cells can differentiate into red blood cells which can replace a patient’s faulty RBCs, embryonic stem cells can differentiate into insulin-producing cells for people with diabetes, they can also be used to replace nerve cells in someone who has a spinal injury..
What is therapeutic cloning?
An embryo is made to have the same genes as a patient so stem cells produced by it would also have the same genetic information and they wouldn’t be rejected.
What are the risks of using lab grown stem cells?
These stem cells may be contaminated with a virus which could be passed onto a patient and make them sicker.
Why are some people against stem cell research?
They believe an embryo shouldn’t be used for experiments as each one is a potential for human life, they feel that scientists should concentrate more on developing other sources of stem cells.
Why do some people agree with stem cell research?
They believe curing the person suffering is more important, they also would argue that embryos used are typically unwanted as they are from fertility clinics so if they weren’t used for research they would likely just be destroyed.
Name some specialised cells
Root hair cells (specialised due to large surface area to maximise water diffusion), red blood cells (specialised due to no nuclei allowing them to fit through tiny capillaries), muscle cells (slide over each other to contract by shortening length) and sperm cells (contain mitochondria for energy)
How are sperm cells specialised
Front of the cell contains digestive enzymes so the sperm cell can enter the egg cell, flagellum used for movement, many mitochondria for energy so it can swim to egg, contains half the DNA
How are egg cells specialised
Contains half the genetic information to allow for fusion, membrane only allows it to be fertilised by one sperm cell, large so it can contain enough nutrients for the early embryo
What are cells called that contain half the number of chromosomes
Haploids/ Gametes
Where are stem cells located in plants?
Meristem
Totipotent meaning
When stem cells can differentiate into any cell
