Answer:
a. Amyloid fibrils have a high amount of β-sheet structure.
c. Because most newly synthesized proteins fold correctly, the accumulation of misfolded proteins (or fragments) tends to occur slowly, thus explaining the slow onset of disease.
e. Proteins that form amyloid fibrils are normally soluble.
Explanation:
Amyloids can be defined as fibrillar protein aggregates composed of a β-sheet secondary structure. In general, the amyloid fibrils are composed by soluble proteins that are assembled to form insoluble resistant to degradation fibers. In humans, defective amyloid proteins produced by misfolding are known to produce diseases (amyloidosis) capable of altering the function of tissues and organs. Systemic forms of amyloidosis are common in neurodegenerative disorders.
Answer:
The correct answer is option E) "Nondisjunction at either meiosis I or meiosis II in the mother".
Explanation:
Nondisjunction is a phenomena at which chromosomes are not properly separated during anaphase. This can either happen at meiosis I or meiosis II during oogenesis. Nondisjunction would explain the XO chromosomic condition of the daughter with Turner syndrome as well as the X-linked recessive allele of the red green color blindness. Nondisjunction happened in the mother because the father could not inherited an X-linked condition.
Answer:
A scientist's response to the increase in food poisoning sick patients should be examining the type and source within the foods consumed.
Explanation:
Food poisoning involves the effects that decomposed or contaminated food can have on a group of people who eat it, and can cause illness in all or most individuals.
Although patients' symptoms should be treated and preventive education provided, the best course of action for a scientist is to investigate the cause.
The response of a scientist to the increase in food poisoning cases is to determine the type and source of food, as well as the nature of the alteration it has -decomposition, contamination, bacteria- in order to <u>eliminate the source and avoid new cases</u>.
- <em>The other options may be valid in the face of the appearance of food poisoning cases, but they are not the best procedure with which a scientist would respond. </em>
Answer:
C. The evolution of many species from a single ancestor over a long period of time
Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
