chapter 14 Flashcards
Heart rate can be increased by the hormone adrenaline, which binds to cardiac cells.
Describe how adrenaline binds to cardiac cells.
(binds to) receptor in, cell surface / plasma, membrane (1)
glycoprotein (1)
Birds and humans have similar pancreas tissues, with the same cell types contributing to exocrine and
endocrine roles.
- Growth hormone (GH) is a peptide hormone that stimulates cell reproduction and regeneration in humans and other animals. It is produced during development to increase muscle mass and increase bone size and density.
GH can also be used in farming to enhance yields from different animals. Design an experiment to investigate the following hypothesis:
“Varying the concentration of GH injected affects the yield of meat from farmed chickens”
You must explain how you would obtain valid data.
- Independent variable – concentration of GH injected
- Dependent variable – rate of
growth - Control variables – animal species, foodstuff, (named) conditions
- Trial populations over several months
- Control group to ensure validity of conclusions
- Method for assessing growth – e.g. % mass change or growth rate to allow comparability
- Different species of chickens should be investigated
- Ensure food is consistent across all trial groups
- Sample size needs to be large enough to reduce effect of anomalies
- Ethical concerns – chickens should be reared in humane conditions
- Consideration of potential negative effects on chickens, e.g. larger muscle mass, so may be unable to move as easily
Studies on the effects of hCG in humans have revealed the following information:
*Many different tissues are affected by hCG.
*Susceptible cells have glycoprotein receptors on their cell surface. *These receptors are complementary to the shape of hCG molecules.
i. What can be concluded from this information?
(hCG is a) peptide hormone / hCG is not a lipid-based hormone (1)
(hCG) binds to cell surface receptor (1)
idea that cell signalling is involved in action of hCG (1)
(hCG) uses cAMP / second messenger, to bring about response in cell (1)
Another hormone produced during pregnancy is oestrogen. Oestrogen is lipid soluble. Which molecule does oestrogen interact with when it changes cell activity?
DNA / deoxyribonucleic acid
A hydatidiform mole is a rare complication of pregnancy that can occur after implantation of the fertilised egg in the uterus. It results in excessive production of hCG and damage to the lining of the womb, leading to miscarriage.
Suggest how a hydatidiform mole could increase hCG above normal levels.
(hydatidiform mole) cells produce more hCG than normal (1)
(due to) expression / up regulation, of genes (1)
synthesising more, hCG / protein(s) (1)
idea that other tissues could be stimulated to produce more hCG than normal (1)
Functions of hormone:
adrenaline
- increases heart rate
- increases blood glucose
concentration - increases blood flow to muscles
- increases glycogenolysis
- causes pupils to dilate
- decreases blood flow to gut
- increases blood pressure
- dilation of bronchioles
- increases air flow to alveoli
- increases breathing rate
Explain why it was necessary to increase the concentration of glucose surrounding the cells before they measured insulin secretion
glucose (concentration) causes release of insulin / AW ✓
change in insulin secretion is high enough to be measured / AW ✓
The statistical test gave a value of p < 0.001. Use the words ‘chance’ and ‘probability’ to draw a conclusion from the result of the statistical test.
probability is, less than / <, 0.1% / 0.001 ✓
(so) results / differences between means, were due to chance ✓
Explain how blocking calcium channels could inhibit insulin secretion.
Ca2+ / calcium ions, do not enter (cells) ✓ less / no, exocytosis ✓
Which type of diabetes mellitus is most likely to be improved by stem cell therapy? Explain your answer.
type I) results from a shortage of beta cells (in the pancreas)✓
idea that stem cell therapy might increase insulin production ✓
idea that type II diabetes usually results from insulin resistance (rather than a lack of insulin)✓
Stem cells were extracted from the bone marrow of 131 patients with diabetes mellitus. Each patient
received an implantation of their own stem cells. Following the stem cell treatment:
* 53 patients showed no change
* 78 patients showed an improvement in their condition.
Suggest three additional pieces of information that would be needed to assess the effectiveness of the stem cell therapy.
the type of diabetes (being treated) ✓
age (of patients) ✓
gender (of patients)✓
idea of how the improvement was measured ✓
idea of when the improvement was measured
Explain why standard deviation is better than range for measuring the dispersion of these data.
less affected by the, 10.9 value / outlier / anomaly ✓
idea of takes into account every value in the data ✓
