EvolutionIB MYP Biology: Topic test

20 questions, 54 marks

IB MYP Biology

Evolution topic test

Total 54 marks

Name

Class

Date

1
A researcher in Kyoto studies a species of salamander. Each body cell of the salamander contains 24 chromosomes. She examines the cells in the testes that make sperm.
(a)
How many chromosomes are in each sperm cell made by meiosis?
[1 mark]
A6
B12
C24
D48
(b)
Which statement correctly describes the cells made when one cell divides by meiosis?
[1 mark]
ATwo genetically identical cells with the full chromosome number
BTwo genetically different cells with half the chromosome number
CFour genetically identical cells with the full chromosome number
DFour genetically different cells with half the chromosome number
(c)
Explain why the fertilised egg of this salamander contains 24 chromosomes, the same number as the body cells.
[2 marks]
Total for question 1: 4 marks
2
Scientists in Helsinki are sequencing a short section of a gene in a bacterium. On one strand of the DNA double helix, the bases read A T G C C G.
(a)
Which sequence of bases is found on the complementary strand opposite A T G C C G?
[1 mark]
AT A C G G C
BU A C G G C
CT A G G C C
DA T G C C G
(b)
What is a mutation?
[1 mark]
AA change in the environment that affects a gene
BThe copying of DNA before a cell divides
CA change in the sequence of bases in DNA
DA pair of chromosomes that carry the same genes
(c)
Explain how a mutation in a gene could lead to a protein that does not work.
[2 marks]
Total for question 2: 4 marks
3
On a cattle farm in Argentina, the gene for horns has two alleles. The allele for being hornless (H) is dominant to the allele for horns (h). A hornless bull is mated with a horned cow and their calf is born with horns.
(a)
Deduce the genotype of the calf and of the bull. Explain your reasoning.
[3 marks]
(b)
The farmer mates the same bull with a different horned cow. List the possible offspring genotypes in a Punnett square and find the probability that the next calf is horned.
[4 marks]
Total for question 3: 7 marks
4
Pest beetles feed on wheat in southern Australia. When a farmer first sprayed a new insecticide in 2005, it killed 99% of the beetles. By 2020 the same spray killed only 20%, and the surviving beetles were found to carry an allele that makes them resistant to the insecticide.
(a)
Explain how the population of beetles became resistant to the insecticide.
[6 marks]
(b)
Discuss whether farmers should keep using this insecticide on their wheat.
[6 marks]
Total for question 4: 12 marks
5
A fossil of Archaeopteryx, found in limestone in southern Germany and about 150 million years old, shows a creature with feathers and wings like a bird. It also has teeth in its jaws, claws on its wings and a long bony tail, like a small dinosaur. The arrangement of the bones in its wing is the same as the arrangement of the bones in the forelimb of a lizard, although the two limbs do different jobs.
(a)
What name is given to structures such as the wing of Archaeopteryx and the forelimb of a lizard, which have the same bone arrangement but different jobs?
[1 mark]
AMutant structures
BVestigial structures
CHomologous structures
DSelected structures
(b)
Which observation gives the strongest evidence that two living species share a recent common ancestor?
[1 mark]
ATheir DNA base sequences are very similar
BThey live in the same habitat
CThey are about the same size
DThey eat the same food
(c)
Explain how the features of Archaeopteryx support the idea that birds evolved from reptile-like animals.
[2 marks]
Total for question 5: 4 marks
6
Two populations of a species of ground squirrel were once a single population. About 10 000 years ago a wide river formed and split their habitat in two. The squirrels cannot swim, so the two populations have lived apart ever since. The habitat on one side of the river is dry grassland and on the other side it is wet woodland.
(a)
What name is given to the separation of the two populations by the river?
[1 mark]
ANatural selection
BMutation
CExtinction
DGeographical isolation
(b)
What must happen before the two populations are counted as different species?
[1 mark]
AThey must look different
BThey can no longer interbreed to produce fertile offspring
CThey must live in different habitats
DThey must have a different number of chromosomes
(c)
Explain how the two populations could evolve into different species.
[2 marks]
Total for question 6: 4 marks
7
Students in Ghana compare the diversity of birds in a natural forest and in a nearby plantation where only one type of tree is grown. In the forest they counted 20 birds along a path, and the birds belonged to four species, with 8, 6, 4 and 2 individuals. The diversity index is calculated using $D = \frac{N(N-1)}{\sum n(n-1)}$ , where $N$ is the total number of individuals and $n$ is the number of individuals of each species.
(a)
Calculate the diversity index for the forest.
[3 marks]
(b)
The students now want to compare the two habitats fairly. Describe how they should collect their samples at both sites, identifying two variables to control.
[4 marks]
Total for question 7: 7 marks
8
The Iberian lynx lives in Spain and Portugal and eats mainly rabbits. By 2002 only about 100 lynx remained. Rabbit numbers had crashed because of disease, and much of the lynx's scrub woodland habitat had been cleared for farming and roads. Conservation groups started captive breeding programmes and restored rabbit populations, and by 2022 more than 1 000 lynx lived in the wild.
(a)
Explain why a species with a very small population is at greater risk of extinction.
[6 marks]
(b)
Discuss whether governments should spend public money on captive breeding programmes for endangered species such as the Iberian lynx.
[6 marks]
Total for question 8: 12 marks

End of questions

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).