Farmers selectively breed chickens to produce larger chickens - Edexcel - GCSE Biology - Question 5 - 2020 - Paper 1
Question 5
Farmers selectively breed chickens to produce larger chickens.
Figure 9 shows how the size of chickens has changed over time.
(i) Explain how farmers have used sele... show full transcript
Worked Solution & Example Answer:Farmers selectively breed chickens to produce larger chickens - Edexcel - GCSE Biology - Question 5 - 2020 - Paper 1
Step 1
Explain how farmers have used selective breeding to produce larger chickens.
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Answer
Farmers have utilized selective breeding by choosing chickens that exhibit desirable traits, such as size, for reproduction. This process involves mating larger chickens over several generations, thereby enhancing the characteristic of size in the offspring. The selection is based on observable traits, and only those chickens that are significantly larger are bred, resulting in a gradual increase in the average size of the chicken population.
Step 2
Describe one benefit and one risk of selectively breeding chickens.
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Answer
Benefit: One key benefit of selectively breeding chickens is the enhanced productivity, resulting in larger chickens that can provide more meat per animal, boosting efficiency in poultry farming.
Risk: A significant risk associated with selectively breeding chickens is the reduction of genetic diversity. This can make the chicken population more susceptible to diseases and reduce their overall adaptability to environmental changes.
Step 3
State the number of chromosomes found in each sex cell of a chicken.
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Answer
Each sex cell of a chicken contains 39 chromosomes.
Step 4
Name the type of cell division which produces sex cells.
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Answer
The type of cell division that produces sex cells is called meiosis.
Step 5
What is the correct definition of a genome?
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Answer
The correct definition of a genome is C: all the genetic material of an organism.
Step 6
State two benefits of discovering the sequence of bases for all plants and animals.
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Understanding the genetic makeup allows for advances in biotechnology, including genetic modification for improved crop yields or disease resistance.
It enhances the ability to conserve biodiversity by identifying and preserving endangered species, ensuring the survival of a wide range of genetic materials.