n":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"392f2600-8137-49f7-922c-6cafb9d97cfd","revisionId":"15ac8e6d-7f36-4899-a8fb-b44748bf6dc5","questionNumber":null,"questionType":"LA","specification":"","difficulty":3,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"371d80bc-dbce-413e-a9bb-827ed49e2183","label":null,"content":"Describe how dairy cows alive today have been selectively bred to produce a larger volume of milk.","markscheme":"- Identifies and selects individuals (cows with the highest milk yields and bulls from high-yielding mothers) from the population B1\n- Breeds these selected individuals together B1\n- Selects the offspring with the highest milk yield and repeats this selection and breeding process over multiple consecutive generations B1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"selective_breeding","label":"Selective breeding","steps":[{"type":"text","order":0,"title":"Start with variation","content":"Milk yield varies naturally within a population of dairy cows. Select the cows with the **highest milk yields** and bulls whose mothers had high milk yields. This is the first marking point: choosing parents with the desired characteristic.","highlights":[{"text":"dairy cows alive today have been selectively bred to produce a larger volume of milk","location":"specification"}]},{"type":"text","order":2,"title":"Breed the chosen parents","content":"Breed the selected cows and bulls together. Their offspring are more likely to inherit alleles for a high milk yield. Stating that the selected individuals are bred together earns the second marking point.","highlights":[{"text":"selectively bred","location":"specification"}]},{"type":"text","order":3,"title":"Repeat the selection","content":"From the offspring, select those with the highest milk yields and breed them. Repeat this selection and breeding over many consecutive generations. This final repetition is essential for the third marking point: it makes high milk yield increasingly common in the herd.","highlights":[{"text":"produce a larger volume of milk","location":"specification"}]}]}],"generatedAt":"2026-07-22T08:52:52.707Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"4d4c19b0-2ade-45c7-84cd-9f1464cbaf9d","revisionId":"a33be0dd-8b93-419e-91de-14059f37448b","questionNumber":null,"questionType":"LA","specification":"","difficulty":6,"difficultyBand":"medium","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"6a1a1d12-152a-4613-8438-9247afb75689","label":null,"content":"Describe how selective breeding can be used to produce a large population of domestic rabbits with a desired trait, such as extremely soft fur, while ensuring the individuals in the population are not closely related.","markscheme":"- Selects individuals with the desired trait (soft fur) from different or unrelated sources, locations, or bloodlines to start the breeding program B1\n- Avoids mating closely related offspring (e.g. siblings or parents) by regularly introducing new, unrelated individuals with the desired trait into the breeding pool (outcrossing) B1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"selective_breeding","label":"Selective breeding","steps":[{"type":"text","order":1,"title":"Choose unrelated parents","content":"First, select rabbits with **extremely soft fur** from different locations or bloodlines. Because the starting rabbits are unrelated, the desired trait is present but the breeding population has a wider range of inherited alleles.\n\nThis selection earns the first mark.","highlights":[{"text":"desired trait, such as extremely soft fur","location":"specification"},{"text":"individuals in the population are not closely related","location":"specification"}]},{"type":"text","order":2,"title":"Continue without inbre

Selective breeding and genetic engineering

Question 6

Selective breeding and genetic engineering Questions

Selective breeding and genetic engineering

Question 6

Selective breeding and genetic engineering Questions