What are farmers looking for when they select animals or plants to use for breeding?
chapter 15
| Question | Answer |
|---|---|
| When farmers select animals or plants to use for breeding, they look for | natural variations that are present in a species |
| when a farmer breeds only his or her best livestock, the process involved is | artificial selection |
What happens in the process of natural selection?
Natural selection is the process through which populations of living organisms adapt and change. Through this process of natural selection, favorable traits are transmitted through generations. Natural selection can lead to speciation, where one species gives rise to a new and distinctly different species.
What three conditions are necessary for natural selection?
The essence of Darwin’s theory is that natural selection will occur if three conditions are met. These conditions, highlighted in bold above, are a struggle for existence, variation and inheritance. These are said to be the necessary and sufficient conditions for natural selection to occur.
Which of the following is not required for natural selection?
Only when variation among organisms is inherited from the previous generation, i.e. it has a genetic basis, will natural selection be able to occur. Natural selection cannot act on variation that is due purely to environmental conditions.
How do farmers selectively breed animals?
Selective breeding takes place over many generations. These are the main steps for both plants and animals: Choose the best offspring with the desired characteristics to produce the next generation. Repeat the process continuously over many generations, until all offspring show the desired characteristics.
What are the four limitations to natural selection?
Terms in this set (4)
- Non-adaptive traits. -vestigial traits.
- Genetic constraints. -gene linkage (no crossover possible; indirect selection due to proximity to selected genes)
- fitness trade-offs.
- historical constraints.
