What are totipotent cells, and what can they do?
Totipotent cells can differentiate into any cell type, including extraembryonic tissues.
How do totipotent cells contribute to cell specialisation?
Totipotent cells express only certain genes, leading to specialisation.
How long do totipotent cells remain in a mammalian embryo?
Totipotent cells exist only in early embryonic stages before differentiating into other stem cells.
Where are pluripotent, multipotent, and unipotent cells found?
Pluripotent cells (embryos) form any body cell, multipotent cells (adults) form a limited range, and unipotent cells form one type.
How can pluripotent stem cells be used in treating human disorders?
Pluripotent stem cells can be used to treat disorders by replacing damaged tissues (e.g., nerve cells for Parkinson’s).
What are unipotent cells, and how do they relate to cardiomyocytes?
Unipotent cells form one cell type, e.g., cardiomyocytes, which help regenerate heart tissue.
How are induced pluripotent stem cells (iPS cells) created?
iPS cells are created by reprogramming adult somatic cells using transcription factors.
What are the ethical and medical considerations in using stem cells for treatment?
Stem cell treatments raise ethical concerns (embryo use) but have medical potential (regenerative medicine).
How can transcription be stimulated or inhibited in eukaryotic cells?
Transcription factors move into the nucleus to stimulate or inhibit transcription.
What is the role of oestrogen in initiating transcription?
Oestrogen binds to transcription factors, enabling them to activate specific genes.
What is epigenetics, and how does it regulate gene expression?
Epigenetics involves gene expression changes without altering the DNA base
sequence.
How does DNA methylation affect transcription?
Increased DNA methylation prevents transcription by blocking RNA polymerase binding.
How does histone acetylation affect transcription?
Decreased histone acetylation causes tighter DNA packing, inhibiting transcription.
How does epigenetics contribute to disease development and treatment, particularly in cancer?
Epigenetic changes can silence tumour suppressor genes or activate oncogenes, leading to cancer.
What is RNA interference (RNAi), and how does it affect gene expression?
RNAi prevents translation by degrading or blocking mRNA.
What are the key characteristics of benign and malignant tumours?
Benign tumours grow slowly, remain localised, and don’t invade tissues, while malignant tumours grow rapidly and spread (metastasis).
What is the role of tumour suppressor genes and oncogenes in cancer?
Tumour suppressor genes slow cell division, while oncogenes promote cell division. Mutations cause uncontrolled growth.
How does abnormal methylation of tumour suppressor genes and oncogenes contribute to cancer?
Hypermethylation of tumour suppressor genes silences them, while hypomethylation of oncogenes activates them, leading to cancer.
How does increased oestrogen concentration contribute to breast cancer development?
Increased oestrogen stimulates excessive cell division in breast tissue, increasing cancer risk.
How can an understanding of oncogenes and tumour suppressor genes be used in cancer prevention, treatment, and cure?
Understanding oncogenes and tumour suppressor genes helps develop targeted therapies for cancer treatment.
How can data be used to interpret gene expression investigations?
Gene expression data can be analysed by comparing RNA levels, protein levels, or gene mutations.
How can we evaluate genetic vs environmental influences on phenotype?
Genetic vs environmental influences can be determined through twin studies, population data, and mutation analysis.
How can evidence be used to evaluate correlations between genetic and
environmental factors in cancer?
Cancer correlations can be evaluated by analysing genetic mutations, environmental exposures, and epidemiological data.
