A heart beats 72 times per minute and pumps 70 cm³ of blood per beat. What is its cardiac output in dm³ per minute?
Answer and explanation
Correct answer: A. 126/25
- Step 1: Cardiac output = heart rate × stroke volume = 72 × 70 = 5040 cm³/min. Step 2. 1 dm³ = 1000 cm³, so 126/25 dm³/min. Answer: 126/25. Why not the others: 252/5 is what you get if you convert cm³ to dm³ with the wrong factor. 5040 is what you get if you forget to convert cm³ to dm³. 71/5 is what you get if you add the numbers.
Practise more Quantitative Biology and Genetics Problems.
Free questions with an explanation for every one, and full timed MDCAT Pakistan mock tests.
More Quantitative Biology and Genetics Problems questions
- In a double-stranded DNA sample 30% of the bases are adenine. What percentage are guanine?
- A coding region of mRNA is 150 nucleotides long including the stop codon. How many amino acids are in the finished polypeptide?
- Two heterozygous parents (Aa × Aa) have two children. What is the probability that the first child is recessive and the second shows the dom…
- A cell has an image length of 40 mm under a microscope magnification of ×500. What is its actual length in micrometres?
- A heart beats 80 times per minute and pumps 70 cm³ of blood per beat. What is its cardiac output in dm³ per minute?
- In a population in Hardy–Weinberg equilibrium, 4/25 of individuals show a recessive trait. What proportion are heterozygous carriers?