D.1
human nutrition
Essential Idea: A balance diet is essential to human health.
Nature of Science: Falsification of theories with one theory being superseded by another: scurvy was thought to be specific to humans, because attempts to induce the symptoms in laboratory rats and mice were entirely unsuccessful.
UNDERSTANDINGS:
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6.6.U1 Insulin and glucagon are secreted by ‘𝛃’ and ‘α’ cells in the pancreas.
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6.6.U2 Thyroxin is secreted by the thyroid gland to regulate metabolic rate and help control blood temperature.
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6.6.U3 Leptin is secreted by cells in adipose tissue and acts on the hypothalamus of the brain to inhibit appetite.
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6.6.U4 Melatonin is secreted by the pineal gland to control circadian rhythms.
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6.6.U5 A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone.
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6.6.U6 Testosterone causes prenatal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty.
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6.6.U7 Oestrogen and progesterone cause prenatal development of female reproductive organs and female secondary sexual characteristics during puberty.
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6.6.U8 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones.
APPLICATIONS & SKILLS:
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Application: Causes and treatment of Type I and Type II diabetes.
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Application: Testing of leptin on patients with clinical obesity and reasons for the failure to control the disease.
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Application: Causes of jet lag and use of melatonin to alleviate it.
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Application: The use of IVF of drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of hormones to induce superovulation and establish a pregnancy.
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Application: William Harvey’s investigation of sexual reproduction in deer.
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Skill: Annotate diagrams of the male and female reproductive system to show names of structures and their functions.
RESOURCES:
