- Summary list for 10.3 Gene pools and speciation
- Mindmaps
- Exam style question about speciation
- Model answer
- Model answer
- Model answer
- Multiple choice questions
- 10.3 Gene pools and speciation 1/1
Learn and test your biological vocabulary using these 10.3 Gene pools and speciation flashcards.
Summary list for 10.3 Gene pools and speciation
Gene pools
- A gene pool consists of all the genes and their different alleles, present in an interbreeding population.
- Evolution requires that allele frequencies change with time in populations.
- Punctuated equilibrium implies long periods without appreciable change and short periods of rapid evolution.
Speciation
- Reproductive isolation of populations can be temporal, behavioural or geographic.
- Speciation due to divergence of isolated populations can be gradual.
- Speciation can occur abruptly.
Student skills and applications
- Application: Identifying examples of directional, stabilising and disruptive selection.
- Application: Speciation in the genus Allium by polyploidy.
- Skill: Comparison of allele frequencies of geographically isolated populations.
Mindmaps
This diagram summaries the main sections of topic 10.3 about gene pools and speciation.
Test if you can draw something like these concept maps from memory.
Exam style question about speciation
Answer the question below on a piece of paper, then check your answer against the model answer below.
Describe how geographical isolation and different selective pressures can lead to speciation [3]
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Test yourself
Multiple choice questions
This is a self marking quiz containing questions covering the topic outlined above.
Try the questions to check your understanding.
START QUIZ!
Which of the following is the best definition of a gene pool?
A gene pool consists of all the genes and their different alleles, present in an interbreeding population.
Imagine that the colourings of these beetles was caused by two genes, each gene with just two alleles. We can see that there is a slight variation in the phenotype, caused by these genes, because each beetle has a unique assortment of alleles.
Suggest what would happen to the frequency of the allele causing the shiny red spot,over several years, if this made beetles more visible to a predator.
Evolution requires that allele frequencies change with time in populations.
In this example, if a predator eats more of the beetles with a red spot, then the frequency of the red spot allele in the gene pool will reduce.
Which of the statements is the best definition of "an allele frequency"?
The allele frequency is simply the number of alleles found in the whole interbreeding population.
Homozygous individuals will have two copies of the allele.
Speciation requires two populations to be "reproductively isolated" from each other.
Which of the following lists three methods of reproductive isolation?
Reproductive isolation of populations can be temporal (they are active at different times), behavioural (courtship of some males does not attract some females, or geographic the animals cannot cross a river, or a mountain.
If two populations of a species are geographically isolated what type of evolution could lead to the situation where two groups of organisms of this species can no longer interbreed if they met?
Divergent evolution can lead to speciation.
In the genus Allium, new species have been know to form very rapidly by a special type of speciation.
It is a condition where gametes containing more than one set of chromosomes produce offspring.
What is this condition called?
Speciation can occur in the genus Allium by polyploidy. Diploid, tetraploid, and other types are common.
The images shows two varieties of strawberries.
One of these fruits came from a polyploid variety.
Which is the best description of the potential advantages of polyploidy?
In the case of these strawberries they are covered in seeds so they are not seedless.
Polyploid varieties can occur naturally but often they are induced by crop breeders because they produce a greater yield.
What is the term which describes long periods of time with no significant change followed by a shorter period of quite fast evolution?
Punctuated equilibrium implies long periods without appreciable change and short periods of rapid evolution.
What is the difference between allele frequency ?
A gene pool consists of all the genes and their different alleles, present in an interbreeding population.
Drag and drop activities
Test your ability to construct biological explanations using the drag and drop questions below.
Isolation of two populations is a mechanism of speciation.
Drag and drop the correct word or phrase into the gap to outline isolation mechanisms.
Behavioural Natural mechanisms seasons Temporal interbreeding physical barrier Breeding selection pressures characteristics
Isolation prevents two groups of a species from . If each of the groups is subjected to differing , their genomes will gradually evolve in different ways due to different genes having favourable in the different environments.
Three forms of isolating are:
- Geographical isolation where a such as a river separates the two populations.
- isolation where the activity times or breeding separate the two populations.
- isolation where members of each group choose to breed only with members of that group
Isolation prevents interbreeding and can lead to speciation over time.
How much of Gene pools and speciation 10.3 HL have you understood?
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