5. Micro & Molecular Biology

Inherited Diseases & Disorders

Explain how red blood cells from an individual with sickle cell anemia “sickle” and why they can cause painful “crises” in nerves and bones. Why is avoidance of dehydration and physical exertion important to avoid these crises? Sickle cell anemia is resultant of a polymorphism, where there is a Glu6Val mutation in the beta-globins of…… Continue reading Inherited Diseases & Disorders

5. Micro & Molecular Biology

Protein Folding, Trafficking & Degradation

Outline how a newly translated polypeptide folds correctly, including in your answer the role of chaperone (Hsp70) and chaperonin (Hsp60). Some polypeptides fold spontaneously once released from the ribosome, but most proteins require assistance to fold correctly. Molecular chaperones assist in the folding of newly synthesised proteins and refolding of misfolded proteins, and exist in…… Continue reading Protein Folding, Trafficking & Degradation

5. Micro & Molecular Biology

Cancer Stuff

Explain how tumour suppressor genes differ from oncogenes. (4m) Oncogenes are linked to cancer via gain-of-function gene mutations that only require 1 of the 2 alleles to be mutated, while tumour suppressor genes are linked to cancer via loss-of-function mutations that require both alleles in a cell to be mutated. Mutations of proto-oncogenes into oncogenes…… Continue reading Cancer Stuff

5. Micro & Molecular Biology

Cell Differentiation & Stem Cells

Embryonic stem (ES) cells exhibit the quality of pluripotency. Define pluripotency. Describe 2 assays that are used to demonstrate the pluripotency of mouse ES cells. Pluripotent cells will give rise to cells under all three germ layers of the embryo proper, which are the endoderm, mesoderm and ectoderm, but not the placental tissue. Pluripotency of…… Continue reading Cell Differentiation & Stem Cells

3. Ecology

#1; Behavioural & Evolutionary Ecology

Microevolution vs Macroevolution: Micro; Changes in gene frequencies within species, due to natural selection by mutation, gene flow and genetic drifts. When continued over long periods of time, these microevolutions lead to macroevolution. Macro; Evolution of major alterations that distinguish higher taxa, including the studies of diversification, extinction, success and failure of major lineages.  …… Continue reading #1; Behavioural & Evolutionary Ecology