Genetic Disorders
Übersicht
Most of what your genes do passes unnoticed. Occasionally a single faulty instruction, or one chromosome too many, produces an effect large enough to shape a whole life. These are the genetic disorders, and they are among the few places in biology where a family diagram, a fraction and a set of symptoms all describe the same thing. Learn to move between those three descriptions and this topic becomes arithmetic rather than memory.
In this lesson you will meet the three inherited conditions the specification names by example, and you will see why one of them shows up in every generation of a family while another can hide for decades in people who feel completely well. You will then look at a different kind of cause altogether, where nothing is wrong with any individual allele and the problem is simply that a cell finished up with the wrong number of chromosomes. This is also the topic where the two tiers of this course ask for genuinely different things, so the lesson marks that boundary as it goes and shows you the plain wording that scores full marks on the Core Tier paper.
Ziele
- Some disorders are inherited. Students should be able to interpret data relating to genetic disorders such as polydactyly, cystic fibrosis and sickle cell anaemia.
- Some inherited conditions are caused by inheritance of abnormal numbers of chromosomes, eg Down’s Syndrome is caused by the presence of an extra chromosome.
Mindmap
Dieses Thema ist als Karte dargestellt, damit die Zusammenhange sichtbar werden.
Mindmap in der App offnen
Lektionshinweis
Vollstaendige Lernnotiz in der Green Bridge App
Holen Sie sich die Green Bridge CBT App auf Handy oder Computer fuer die komplette IGCSE-Bibliothek: fruehere Pruefungen, Bewertungsschemata, Mindmaps, Lernkarten und Audiolektionen.
Unterrichtsbewertung
Herzlichen Glückwunsch zum Abschluss der Lektion über Genetic Disorders. Jetzt, da Sie die wichtigsten Konzepte und Ideen erkundet haben,
Sie werden auf eine Mischung verschiedener Fragetypen stoßen, darunter Multiple-Choice-Fragen, Kurzantwortfragen und Aufsatzfragen. Jede Frage ist sorgfältig ausgearbeitet, um verschiedene Aspekte Ihres Wissens und Ihrer kritischen Denkfähigkeiten zu bewerten.
Nutzen Sie diesen Bewertungsteil als Gelegenheit, Ihr Verständnis des Themas zu festigen und Bereiche zu identifizieren, in denen Sie möglicherweise zusätzlichen Lernbedarf haben.
- Cystic fibrosis is caused by a recessive allele f. The working allele is F. Which pair of alleles is carried by a carrier of cystic fibrosis? A. FF B. Ff C. ff D. A carrier has no alleles for this gene Answer: B
- Polydactyly is caused by a dominant allele. Which statement is correct? A. A person needs two copies of the allele to have the condition B. A person with one copy of the allele has the condition C. The condition always skips a generation D. Only females can have the condition Answer: B
- How many chromosomes are found in a body cell of a person with Down's syndrome? A. 23 B. 45 C. 46 D. 47 Answer: D
- Two carriers of cystic fibrosis have a child. What is the percentage chance that the child has cystic fibrosis? A. 0% B. 25% C. 50% D. 75% Answer: B
- Which of the following describes the event that leads to Down's syndrome? A. A dominant allele is inherited from one parent B. A recessive allele is inherited from both parents C. A pair of chromosomes fails to separate during meiosis D. A chromosome is lost during mitosis in the adult Answer: C
Bearbeiten Sie diese Fragen in der App
Bearbeiten Sie diese Fragen in der App
Empfohlene Bücher
Übungsklausuren üben
Möchten Sie Übungsklausuren zu Genetic Disorders üben? Laden Sie die Green Bridge CBT App herunter, um Übungsklausuren und vollständige Prüfungssimulationen zu diesem Thema zu erhalten.
Lade die App im Google Playstore herunter.
Alles, was du brauchst, um in JAMB, WAEC & NECO zu glänzen.
