Evolution & Natural Selection (DP IB Biology: HL)

Why do species evolve over time?

Which of the following must occur for speciation to take place?

1. Two populations of a species must be separated by a mountain range or body of water.
2. No gene exchange can take place between two populations of a species.
3. Two populations must develop differences in their physical characteristics.

The image below shows a series of fossils.

How does this set of fossils provide evidence for evolution?

The diagram below shows how selective breeding has developed several modern crop varieties from wild wheat.

The selective breeding of modern wheat from wild wheat would begin with the breeders selecting individuals with many, large seeds.

What is the correct continuation of the process for the selective breeding of modern wheat from wild wheat?

Which of the following processes generate genetic variation?

1. Random assortment
2. Mitosis
3. DNA replication
4. Random fertilisation

Which of the following must occur for natural selection to take place?

Which of the following is not a reason for the evolution of melanism in peppered moths?

Research was carried out on beak size in the island-living finch species Geospiza fortis. G. fortis feeds on seeds, which are plentiful, small, and soft in the years when the weather is normal, but which become larger and tougher in drought years. Some of the research results are shown in the graph below.

Which of the following statements explains the results in the graph?

Which of the following would reduce the likelihood of antibiotic resistance evolving?

1.  Reducing the use of antibiotics.
2. Taking measures to reduce the spread of infectious bacteria.
3. Researching new antibiotics.

Research was carried out into the emergence of antibiotic resistance in the antibiotics used to treat infection X between the years 2000-2016.

Different antibiotics were recommended during different time periods due to concerns about developing resistance. Note that ciprofloxacin is used to treat a range of infections and not just infection X, while tetracycline is not used to treat infection X but is used to treat many other mild infections.

Some of the results of the research are shown below.

 What conclusion can be drawn from these results?

The image shows the general skull structure of reptiles and mammals, as well as details of the structures inside their ears. The labels A-C indicates structures that evolutionary biologists think are equivalent to each other in both reptiles and mammals.

Which is the most likely explanation for the structures shown in the image?

Several species of lava lizard of the genus Microlophus are found only in the islands of the Galapagos. A group of scientists recorded the mating displays of male lava lizards in different parts of the Galapagos, using the amplitude of a wave to represent the height and length of head bobbing behaviour. The map shows the mating displays of some male lava lizards currently living on different islands of the Galapagos.

Which of the following statements about mating displays in Galapagos lava lizards are correct?

I. Mating displays are the same between members of the same species of lava lizard

II. Mating displays show continuous variation across the geographical range of the Galapagos lava lizards

III. The mating displays suggest that lava lizards evolved by gradual divergence from a common ancestor

IV. The mating displays recorded show all the stages of lava lizard divergence

In adult humans, the ability to digest the lactose sugar in milk depends on the presence of an allele known as -13910*T. Individuals with this allele continue to produce the enzyme lactase into adulthood; this is known as lactase persistence. Individuals without this allele are not able to produce lactase after infancy and cannot digest lactose as adults. The table below shows the frequency of the -13910*T allele in European Neolithic hunter-gatherers who lived around 5 000 years ago and in modern Europeans.

Which of the following can be concluded from the table?

The pneumococcal conjugate vaccine (PCV13) provides protection against infection caused by the bacterium Streptococcus pneumoniae. The graph shows the number of cases of invasive pneumococcal disease (IPD) caused by antibiotic resistant S. pneumoniae before and after the introduction of PCV13.

Which statement correctly explains the number of cases of IPD caused by antibiotic resistant S. pneumoniae after the introduction of PCV13?

The pelvic bones of whales are located in the equivalent position to the hip bones of land mammals, though they are not attached to the rest of the skeleton. These bones have long been thought of as vestigial structures leftover from the process of evolutionary change. Scientists researched the relationship between the size of whale pelvic bones and the size of whale testes. The graphs show some of the results of the study.

Which of the following statements relating to whale pelvic bones are correct?

I. Whale pelvic bones are homologous to the pelvic bones of land mammals.

II. There is no relationship between the body size of a whale, as represented by rib size, and the size of a whale's testes.

III. The pelvic bones of whales are vestigial structures with no function.

IV. The pelvic bones of whales are not vestigial but are involved in reproduction.