Heart, circulation and blood vessels：練習問題

Which of the following descriptions correctly identifies the structure of amylopectin?

During a Daphnia heart rate investigation, which of the following is a necessary ethical consideration and a valid procedural step?

Which of the following identifies the correct mechanism by which High-Density Lipoproteins (HDLs) differ from Low-Density Lipoproteins (LDLs) in their effect on atheroma formation?

Which statement correctly describes a structural difference between amylose and amylopectin?

During the cardiac cycle, the coordination of pressure changes is vital for efficient blood flow. Which statement correctly describes the state of the heart valves during the phase of ventricular diastole when the ventricles are filling with blood?

State one reason why many large, multicellular organisms require a circulatory system to transport substances around their bodies.

During a study on cardiovascular health, a researcher finds a strong positive correlation between sugar intake and heart disease. Explain why this correlation does not necessarily prove that sugar causes heart disease.

A longitudinal study identifies a correlation between high salt intake and the incidence of hypertension. Explain why this result alone is insufficient to conclude that salt causes high blood pressure, and identify one confounding variable that must be controlled to improve the study's validity.

Topic 1: Lifestyle, Health and Risk
A study was conducted to compare the effects of different types of lipid on blood cholesterol levels. Two groups of participants were monitored: Group A consumed a diet high in saturated fatty acids, while Group B consumed a diet high in unsaturated fatty acids.

(a) Describe the structural differences between a saturated fatty acid and an unsaturated fatty acid.
(b) Explain why a high level of Low-Density Lipoproteins (LDLs) in the blood is considered a risk factor for cardiovascular disease (CVD).
(c) Suggest how a diet high in saturated fats might lead to the development of atherosclerosis. <\/p>

Blood pressure is a significant risk factor for cardiovascular disease (CVD). The following data represents the systolic blood pressure readings of a 55-year-old male over a period of four weeks while monitoring his response to a new exercise regime:

Week 1: 155 mmHg
Week 2: 148 mmHg
Week 3: 142 mmHg
Week 4: 138 mmHg

(a) Calculate the percentage decrease in systolic blood pressure between Week 1 and Week 4. Show your working.
(b) Explain how antihypertensive drugs, such as ACE inhibitors, can be used to treat individuals with consistently high blood pressure and identify one potential risk associated with their use.
(c) State why a decrease in blood pressure reduces the risk of atherosclerosis.