10.1 Flashcards
What is a gene?
A section of DNA that codes for the amino acid sequence of proteins
How are the members of species the same?
They all have the same genes however members of the same species have different alleles.
What is the benefit of a species having a high genetic diversity?
High genetic diversity means a greater number of alleles that all members of a species possess. The higher genetic diversity means that the species is more likely to adapt to environmental change because a wider range of alleles means a wider range of characteristics. Therefore, there is a greater probability that there is a member of a species that has a characteristic that is suitable for the new environment thus increasing the chances of survival
What is selective breeding/artificial selection?
Identifying individuals with desired characteristics and using them to parent the next generation. Offspring without the desired characteristics are often killed or prevented from breeding. This reduces genetic diversity as alleles decrease to a restricted/controlled amount.
Why is selective breeding carried out?
To produce high-yielding breeds of domesticated animals or strains of plants like wheat.
What is the founder effect?
The founder effect occurs when a few population members colonise a new region. These members will have a small fraction of the alleles possessed by the whole population thus it isn’t representative of the whole population. This new population will have less genetic diversity than the population it was originally from. The new population may develop into a new species.
What is a genetic bottleneck?
A genetic bottleneck occurs when a large, genetically diverse population is drastically reduced by chance. (A colony of ants dying due to getting stepped over by pedestrians). The survivors will possess less alleles than the original population, reducing the genetic diversity of the population.
What is genetic drift?
Occurs due to a random change in allele frequency and it occurs by chance. For example: In a small population of 10 rabbits, if 3 rabbits carrying a specific allele fail to reproduce, that allele might disappear entirely by chance.
What is the connection and difference between genetic drift and genetic bottleneck?
Connection: A genetic bottleneck often results in a small population, making it more susceptible to genetic drift.
Key Difference: A bottleneck is a specific event that reduces population size, while genetic drift is the random fluctuation in allele frequencies over time.
How can genetic diversity be measured between species?
- The base sequence of DNA or mRNA
- The frequency of specific base sequences or alleles in populations
- The amino acid sequence of encoded proteins.
