IB Biology HL A2.1 Origins of cells questions

Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.

Type
Multiple choiceWritten
Difficulty
EasyMediumHard

Question 1

Paper 2Easy6 marks

A research group summarized its estimates for the ages of the first living cells and the last universal common ancestor (LUCA) in Figure 1. The estimates are ranges in Ga, where 1 Ga is one billion years before the present. The estimate for the first living cells was based on fossilized evidence in ancient seafloor hydrothermal-vent precipitates; the estimate for LUCA was based on conserved sequences from genomic analysis.

00.20.40.60.811.21.41.61.822.22.42.62.833.23.43.63.84Estimated time before present / GaFirst living cellsLUCA
(a)

Using Figure 1, state the estimated age range for each of the first living cells and LUCA.

[2]
(b)

State the interval in which the two estimates overlap.

[1]
(c)

State what the fossilized evidence in ancient seafloor hydrothermal-vent precipitates indicates.

[1]
(d)

State what conserved sequences from genomic analysis indicate about LUCA.

[1]
(e)

Using Figure 1, state what the age estimates show about the time scale over which life has been evolving.

[1]