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Blood glucose concentration in the human body needs to be kept within the normal range - AQA - GCSE Biology: Combined Science - Question 5 - 2022 - Paper 2
Question 5
Blood glucose concentration in the human body needs to be kept within the normal range. Figure 4 shows that two hormones control blood glucose concentration. Figu... show full transcript
Worked Solution & Example Answer:Blood glucose concentration in the human body needs to be kept within the normal range - AQA - GCSE Biology: Combined Science - Question 5 - 2022 - Paper 2
Step 1
Step 3
05.3 Explain how the two hormones in Figure 4 keep the blood glucose concentration within the normal range for 3 hours after a meal.
Answer
After a meal, blood glucose concentration increases, stimulating the pancreas to secrete insulin.
Insulin facilitates the uptake of glucose by the liver and muscle cells and promotes the conversion of excess glucose into glycogen for storage, leading to a decrease in blood glucose levels. This process helps maintain blood glucose levels within the normal range.
When blood glucose levels drop, the pancreas secretes glucagon, which causes the liver to break down glycogen into glucose, thus raising blood glucose levels as needed and keeping them stable.
Step 4
05.4 Explain how injecting FSH and then LH will help a woman to become pregnant.
Answer
Injecting FSH stimulates the development of several follicles in the ovary, each containing an egg. When these follicles mature, a subsequent injection of LH triggers ovulation, releasing a mature egg. This synchronized hormonal stimulation increases the chances of successful fertilization during sexual intercourse.
Step 5
05.5 Describe the remaining steps in IVF.
Answer
In IVF, after retrieving mature eggs from the ovaries, these eggs are fertilized in a laboratory using sperm. The fertilized eggs develop into embryos over a few days. One or two viable embryos are then selected and transferred into the woman’s uterus to implant and develop into a pregnancy.
Step 6
05.6 Describe three differences between cell division to form sperm cells compared with cell division to form liver cells.
Answer
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Sperm cells are produced through meiosis, leading to four genetically different sperm cells, while liver cells are produced through mitosis, resulting in two genetically identical liver cells.
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Sperm cells have 23 chromosomes, making them haploid, while liver cells have 46 chromosomes, being diploid.
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The function and lifespan of sperm cells are different; they are designed for reproduction and have a limited lifespan, whereas liver cells are part of metabolic processes and have a longer functional life.