IB Biology SL A4.1 Evolution and Speciation Question Bank
Practise IB Biology SL A4.1 with questions on variation, natural selection, speciation, adaptation and changes in biodiversity.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Practise IB Biology SL A4.1 with questions on variation, natural selection, speciation, adaptation and changes in biodiversity.
Explain how the process of evolution occurs.
a. evolution is «cumulative» change in population/species over time OR
change in allele frequency
b. a population has variations amongst the individuals
c. due to meiosis
OR sexual reproduction
d. due to mutations
e. certain variations give an advantage to some organisms over others in certain environments
f. populations/species produce more offspring than the environment can support
g. individuals of the species compete for the same resources
h. the better-adapted organisms tend to survive and reproduce OR less adapted organisms tend to die or reproduce fewer offspring
i. individuals «that reproduce» pass on their «heritable» characteristics/alleles/genes to their offspring
j. natural selection increases the frequency of «heritable» characteristics/alleles/genes of the better-adapted organisms
k. specific example described
Marking guidance:
Award [7 max] if no reference to heritable characteristics or alleles.
"Traits" is an acceptable alternative to "characteristic".
Accept "genes".
Example must be "described" to award marks.
8 max
What is a piece of evidence that all living organisms share a common ancestor?
They manufacture the same proteins.
They obtain energy from glucose.
DNA triplets code for the same amino acids.
Cells can synthesise all the amino acids.
C
Jersey (Bos taurus) is a breed of cattle. Cows of this breed produce higher milk yields than cows from other cattle breeds.

What has caused this breed to produce higher milk yields than other cattle breeds?
Natural selection
Selective breeding
Adaptive radiation
Random mutations
B