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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. Figur... 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
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0.5.3 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 rises, prompting the pancreas to secrete insulin (B). Insulin facilitates the uptake of glucose by cells and promotes conversion into glycogen for storage in the liver and muscle cells.
Meanwhile, glucagon (A) is secreted when blood glucose levels are low, stimulating the breakdown of glycogen back into glucose, thereby preventing levels from dropping too low. This balance ensures blood glucose concentration remains within the normal range for approximately three hours post-meal.
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0.5.4 Explain how injecting FSH and then LH will help a woman to become pregnant.
Answer
Injecting Follicle Stimulating Hormone (FSH) stimulates the growth and maturation of ovarian follicles, which contain the eggs. Following this, the injection of Luteinising Hormone (LH) triggers ovulation, releasing a mature egg from the follicle. This combination increases the likelihood of fertilization as it ensures that healthy ova are available for potential fertilization during sexual intercourse.
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0.5.5 Describe the remaining steps in IVF.
Answer
In In Vitro Fertilisation (IVF), once the eggs are collected from the ovaries, they are fertilized in a laboratory by sperm cells. The fertilized eggs develop into embryos in the lab. Subsequently, one or more healthy embryos are selected and inserted into the uterus or womb to allow for implantation and the potential for pregnancy.
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0.5.6 Describe three differences between cell division to form sperm cells compared with cell division to form liver cells.
Answer
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Meiosis is the process used to form sperm cells, resulting in four genetically different sperm cells, while liver cells undergo mitosis, producing two genetically identical liver cells.
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Sperm cells have 23 chromosomes and are haploid, meaning they contain half the number of chromosomes of the original cell, while liver cells have 46 chromosomes and are diploid.
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The primary role of sperm cells is reproduction, whereas liver cells are involved in metabolism and other essential bodily functions.