Topic 8 A Flashcards
(32 cards)
What are the 6 types of mutations?
Substitution, deletion, addition, duplication, inversion and translocation
What are hereditary mutations?
When a gamete contains a mutation for a genetic disorder
What is a frameshift mutation?
When the numbe rof bases cahnge causing a shift in the base triplet that follows so triplet code is read differently
What are mutagenic agents?
Something that increases the rate of mutations
How do tumour suppressor genes control cell division?
Slow cell division by producing proteins that stop cell division or cause apoptosis
What happens if a mutation occurs in tumour suppressor geness?
They will be inactivated, protein it codes for isn’t produced and cells uncontrollably divide causing a tumour
How do proto-oncogenes control cell division?
Produce proteins that stimulates cell division
What happens if a mutation occurs inproto-oncogenes?
Gene can become over reactive, stimulates cell to divide uncontrollably resulted in a tumour. Mutated gene is called oncogene
What are malignant tumours?
Cancerous, grow rapidly and invade and destroy surrounding tissue. Cells can break off and spraed to other parts of the body
What are benign tumours?
Non cancerous, grow slower and covered in fibrous tissues that stop cells invading other tissues. Can cause blockages and put pressure on organs, some can become malignant
How are tumour cells different from normal cells?
Larger and darker, irregular shape, dont produce all proteins needed top function, different antigens, dont respond to growth regulating processes and divide more frequently
How does methylation cause tumour growth?
Adding methyl groups is important to regulate gene expression, control if a gene is transcribed and translated
What happens when tumour suppressor genes are hypermethylated?
Methylation happens too much, genes not transcribed, proteins they produce to slow cell division isnt made so cells uncontrollably divide
What happens when tumour suppressor genes are hypomethylated?
Methylation happens too little, cause them to act as onco-genes, production of proteins that encourage cell division is increased so cell divides uncontrollably
How can oestrogen cause breast cancer?
Increased exposure over a long period of time can increase risk, stimulate certain breast cells to divide uncontrollably, if cells become cancerous replication could be further assisted by oestrogen, can introduce mutations directly into DNA
What does totipotent mean?
Can specialise into any type of cell
What does pluripotent mean?
Can specialise into any cell but placenta cells
What does multipotent mean?
Can differentiate into a few cells
What does unipotent mean?
Can differentiate into one cell
Where do adult stem cells come from?
Bone marrow
Where do embryonic stem cells come from?
Embryos
Where do induced pluripotent stem cells come from?
Created in lab
What do transcription factors do?
Control rate of transcription
How do transcription factors work?
Move from cytoplasm to nucleus and bind to specific DNA sites called promoters (found near start of target gene, the one they control the expression of)
