U7T4 – Variation, Evolution and Speciation

Which of the following is a cause of variation?

Which of these is a source of variation?

In the creation of gametes, which process mixes up the alleles?

What is 'crossing over'?

Which of the following is not a cause of variation?

Natural Selection is when organisms which are better adapted are more likely to survive and pass on their genes. Factors which affect the chance of survival are called selection pressures. These can be positive ( advantageous) or negative ( disadvantageous). Which of these is a negative selection pressure?

Natural Selection is when organisms which are better adapted are more likely to survive and pass on their genes. Factors which affect the chance of survival are called selection pressures. These can be positive ( advantageous) or negative ( disadvantageous). Which of these is a negative selection pressure?

Natural Selection is when organisms which are better adapted are more likely to survive and pass on their genes. Factors which affect the chance of survival are called selection pressures. These can be positive ( advantageous) or negative ( disadvantageous). Which of these is a negative selection pressure?

Natural Selection means that over time the frequency of beneficial alleles in a population will do what?

Which type of selection is when the number of individuals with a particular characteristic, increase around a middle or mid value, and outliers decrease?

Which type of selection is when the number of individuals with a particular characteristic, increase around an extreme or outlier value?

Which type of selection is when the number of individuals with a particular characteristic, split into two groups?

Which type of selection is shown by Darwins finches, where small and large beaks were both at an advantage due to different food sources?

What type of variation is show in the graph?

Which type of selection is shown by fossils of black bears, showing them becoming bigger during glacial periods ( ice ages)?

What type of variation is show in the graph?

Which type of selection is human birthweight showing? (As low birth - weight babies and high birth - weight babies are less likely to survive)

What type of variation is show in the graph?

Speciation is when a new species arises from another: they can no longer produce fertile offspring because their DNA is no longer compatible. What term describes this inability between two populations to reproduce successfully?

What type of speciation is caused by a physical barrier between two populations such as a body of water?

What type of speciation is caused by reproductive Isolation, but without a physical barrier between two populations?

An alteration in bird calls caused by difference in beak size, preventing mating calls between individuals of the same population is an example of what type of speciation?

Natural selection can change allele frequencies over time, due to those with the best alleles surviving and reproducing. What is the term used to describe the 'chance' or 'random' selection of alleles in a population?

What type of population does genetic drift have the greatest effect on?

Which of the following isn't an example of genetic drift?