Cats belong to the Felidae family. Leopardus and Panthera are two genera within Felidae. Leopardus contains small wild cat species with spotted coats. In 2013, biologists studied the evolution of Leopardus tigrinus in South America. Fig. 3.1 shows where two South American populations of L. tigrinus, population A and population B, are found. Population A lives in grassland and desert habitats, whereas population B lives in forest habitats. The cats in population A have a lighter coat colour and a spot pattern that differs from the cats in population B. Genetic analysis indicates that population A is genetically distinct from population B. Population B has therefore been reclassified as a new species, L. guttulus.
(a(i))[2]
What does the term species mean?
(a(ii))[5]
Explain how the two species, L. tigrinus and L. guttulus, evolved from one ancestral population in South America.
(b(i))[3]
Illegal trade puts endangered species at risk. Forensic tests can identify animal species from the DNA in their body parts, such as bones. Cat species vary in the number of C and A base repeats (CA repeats) in one specific DNA region called Ple46. Gel electrophoresis is used to estimate the length of Ple46 in a DNA sample to check whether the sample belongs to one of the endangered cat species. Outline how gel electrophoresis is used to confirm whether the sample comes from one of these endangered cat species.
(b(ii))[2]
Customs officers have to check whether animal body parts originate from species listed by CITES as endangered. They can now use a compact DNA barcoding kit connected to a computer database to identify a species. Suggest two advantages of using this method to identify a species.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “organisms that are morphologically similar” …