Differentiation
Unspecialised cells become specialised
Somatic cell
Body cells that divide by mitosis
Stem cell
Unspecialised somatic cells that can divide to make copies of themselves and/or differentiate into specialised cells
How does a stem cell differentiate into one type of cell rather than another?
Certain genes are switched on and expressed
Name the three components of a nucleotide of DNA.
Name the four bases in DNA
State the base pairing rule
A - T
C - G
What types of bond hold the two DNA strands together?
Hydrogen bonds between the nitrogenous base hold the two strands of DNA together.
Which part of the DNA strand is the 3’ end?
Deoxyribose
What is meant by the term anti-parallel in DNA?
The two sugar-phosphate backbones run in opposite directions
What is a chromosome?
Tightly coiled DNA packaged with proteins
Describe the stages involved in DNA replication
Phenotype
A protein produced as a result of the expression of genes
State three differences between DNA and RNA
Name the four main body tissues
What makes up a ribosome?
2. Protein
Describe the stages of transcription
Describe the stages of translation
Multipotent stem cell
A cell that can differentiate into any cell type within that tissue (eg tissue stem cells)
Pluripotent stem cell
A cell that can differentiate into any cell type (eg embryonic stem cells)
Germ line cell
A cell that gives rise to sperm and egg
What two types of cell division do germ line cells carry out?
2. Meiosis
Name two therapeutic uses of stem cells
2. Skin grafts
Why are stem cells used as model cells?
2. To investigate how diseases develop