SSC CGL 2024 Tier-I · 10 September 2024, Shift 3 · General Awareness · Question 10 of 100

Text as printed on a candidate's response sheet for this shift; answer per SSC's tentative key as marked on that sheet. Solution last reviewed 6 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. The questions and options here are reproduced as printed on a candidate's own response sheet for this shift — the Commission's text, unchanged. Each answer is SSC's tentative key as marked on that sheet; SSC allowed challenges to it and never publishes a final key. The solutions are written by UnlockIAS.

Which of the following characteristics is NOT of Aves?

(a)They give birth to live young ones with some exceptions those lay eggs.
(b)They have four-chambered heart.
(c)They breathe through the lungs
(d)These are warm-blooded animals.

Answer

Why

Correct — A. All birds lay eggs. Aves are oviparous without exception, so a line that gives them live birth with a few egg-laying exceptions is describing mammals, not birds.

The other three statements are genuine avian characteristics: a four-chambered heart, breathing through lungs, and a warm-blooded body.

The stem asks which characteristic is NOT of Aves, so the one false line is the answer and the three true ones are the traps.

Why the others are wrong

(b)
They have four-chambered heart. — A four-chambered heart is genuinely avian — two atria and two ventricles keep oxygenated and deoxygenated blood apart. A true statement cannot answer a NOT question.
(c)
They breathe through the lungs — Birds do breathe through lungs, helped by air sacs that drive air through in one direction. True of Aves, so it is not the exception the stem wants.
(d)
These are warm-blooded animals. — Birds are warm-blooded, holding a steady body temperature whatever the surroundings do. Another true characteristic, so not the odd one out.

Concept

Aves are defined by a short checklist, and SSC flips one line of it.

Birds have feathers, forelimbs modified into wings, a beak without teeth, and hollow pneumatic bones that keep them light.

Internally they are warm-blooded, with a four-chambered heart and lungs served by air sacs. They reproduce by laying eggs, and the egg has a hard calcareous shell.

The contrast that makes this question work is with Mammalia, which is viviparous with the egg-laying monotremes as the exception. The option borrows the mammalian sentence word for word and attaches it to birds.

Key facts

All birds are oviparous — they lay eggs, with no exceptions.
Aves have a four-chambered heart and are warm-blooded.
Birds breathe through lungs assisted by air sacs.
Bird bones are hollow and pneumatic and the forelimbs are modified into wings.

Study next

Class Mammalia — viviparity and the egg-laying monotremesClass Reptilia — three-chambered heart and the crocodile exceptionVertebrate classes in order with one defining feature each

Common traps

Missing the word NOT and marking a statement because it is true.
Carrying the mammalian rule about live birth across to birds.

The Aves set recurs across the corpus in three shapes — which organisms are Aves at 10 Sep 2024, 09:00, GA Q.23, which genus is NOT a member of Aves at 25 Sep 2024, 12:30, GA Q.10, and which class holds the turtles at 24 Sep 2024, 12:30, GA Q.13.

Learn the class characteristics as a checklist, because SSC alters one line and asks you to find it.

Related PYQs

No directly related past PYQ was found.