Which is the hierarchy of taxa in order of increasing numbers of species?

A. genus, family, order, class

B. class, order, genus, family

C. genus, family, class, order

D. class, order, family, genus

To which phylum does the earthworm Lumbricus rubellus belong?

[Source: Casselmann, H., 2011. Lumbricus rubellus HC1. [image online] Available at: https://commons.wikimedia.org/
wiki/File:Lumbricus_rubellus_HC1.jpg (CC BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en [Accessed 23 March 2020].]

A. Annelida

B. Cnidaria

C. Platyhelmintha

D. Arthropoda

An animal shows radial symmetry, has only one opening leading to a digestive cavity and is soft without a skeleton. To which phylum does this animal belong?

A. Platyhelmintha

B. Annelida

C. Mollusca

D. Cnidaria

The graph shows the song duration of birds from the genus Phylloscopus sampled from west to east throughout Northern Europe and Northern Asia.

What concept do these data illustrate?

A. Gradual divergence

B. Adaptive radiation

C. Interbreeding populations

D. Punctuated equilibrium

The photograph shows vegetation in a rocky area.

Which characteristic of the plants indicates that the area in which they are growing is probably dry?

A. Relatively small size

B. Small flowers

C. Narrow leaf surface

D. Small root system

What are the evolutionary origins and functions of homologous structures?

The scientific name of the great egret has recently been changed from Casmerodius albus to Ardea alba.

What is a possible reason for the reclassification of egrets?

A. Allopatric speciation
B. Discovery of different ancestry
C. A change in the mating behaviours
D. Change in habitat and geographic range

What could be used as evidence for evolution?

I. Selective breeding of domesticated animals

II. The fossil record

III. Homologous structures

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

Prickly pear cactus plants are well adapted to desert conditions. The stems are the flattened structures visible in the image and the leaves are reduced to spines. The white spots in the image are groups of spines.

[Source: Stan Shebs/Wikimedia. File licensed under CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0/)]

Which characteristic describes the advantage of one of their adaptations?

A. Leaves are reduced to spines to lose less carbon dioxide.

B. Spines increase surface area for more photosynthesis.

C. Stems are flattened to allow more water to be stored between periods of rain.

D. Waxy cuticle on the stems is very thin to allow rapid absorption of rain.

The cladogram shows some major orders of placental mammals and is based on biochemical evidence.

[Source: © International Baccalaureate Organization 2019]

Which conclusion can be drawn from evidence in the cladogram?

A. Primates and Sirenia have not evolved from a common ancestor.

B. Primates and Cetacea do not form part of any clade.

C. Cetacea are less closely related to Sirenia than to Primates.

D. Xenarthra have not been changed by evolution for longer than other clades.

A bacterial population with no resistance to an antibiotic may develop into a bacterial population with some resistance to an antibiotic. Which event could lead to this?

A. Antibiotic resistance was inherited from an ancestral population.

B. An antibiotic resistance plasmid is received from a bacterium in another population.

C. The enzyme needed for antibiotic resistance is received from a bacterium in another population.

D. The bacterial population mutated in response to antibiotics in the environment.

Which of the adaptations of flowers would be most successful for the survival of a species?

A. Spiny seeds for better wind dispersal

B. Different flowering times for better seed dispersal

C. Sticky pollen for better water dispersal

D. Specific odours for better insect pollination