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GATE 2023 BT Q.37: solution and answer

GATE 2023 · BTQ.37 · 2 marks · MCQ

Match the type of bacteria in Group I with their respective growth properties in Group II.

Group I: P. Halophile; Q. Piezophile; R. Mesophile; S. Xerophile.
Group II: 1. Grows optimally between 20 °C and 45 °C; 2. Grows best at low water activity; 3. Grows at high level of salt; 4. Grows optimally at high hydrostatic pressure.

GATE 2023 BT question 37: A two-column matching table.Tap to open full size
Figure from the GATE 2023 BT paper. It is part of the question.
Figure description

A two-column matching table. Header row: Group I | Group II. Rows: P. Halophile | 1. Grows optimally between 20 °C and 45 °C; Q. Piezophile | 2. Grows best at low water activity; R. Mesophile | 3. Grows at high level of salt; S. Xerophile | 4. Grows optimally at high hydrostatic pressure.

  1. (A)

    P-3, Q-4, R-1, S-2

  2. (B)

    P-2, Q-3, R-4, S-1

  3. (C)

    P-3, Q-1, R-2, S-4

  4. (D)

    P-4, Q-3, R-1, S-2

Answer and solution

ANSWER

The correct matching is P-3, Q-4, R-1, S-2, which is option (A).

Official answer: ASource: Official answer key, GATE 2023 BT (IIT Kanpur)

  1. Halophile: the name means salt-loving. It needs and grows at a high level of salt, so P matches 3.

  2. Piezophile (barophile): the name comes from the Greek for pressure. It grows best at high hydrostatic pressure, as in deep-sea trenches, so Q matches 4.

  3. Mesophile: grows at moderate temperature, with an optimum between about 20 °C and 45 °C. Many human-associated bacteria, such as E. coli, are mesophiles. So R matches 1.

  4. Xerophile: the name means dry-loving. It tolerates or prefers very low water activity (), as in dry or sugary habitats, so S matches 2.

  5. The full matching is P-3, Q-4, R-1, S-2.

  6. Check the options. B puts P with 2 and R with 4, which is wrong. C puts Q with 1 and R with 2, which is wrong. D puts P with 4 and Q with 3, which swaps salt and pressure. Only A is consistent.

KEY IDEA

The name of each group of microbes tells you its preferred condition: halo means salt, piezo means pressure, meso means moderate temperature (about 20 to 45 °C), and xero means dry (low water activity).

WATCH OUT FOR

Confusing a halophile (high salt) with a xerophile (low water activity). Both live in water-poor settings, but a halophile is defined by salt and a xerophile by dryness. Another slip is swapping salt and pressure for halophile and piezophile.

From the GATE 2023 BT paper. Every question of this paper · Download the full paper · All 8 Microbiology questions, with notes

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