SSC CGL Science – Genetics, Evolution & Plant Biology – Level 3 · Challenge

← Back

SSC CGL Science – Genetics, Evolution & Plant Biology – Level 3 · Challenge – 8 questions, subject: General Science. Every question has the correct answer with a one-line explanation; tap "Show Answer". Free practice for TNPSC, UPSC, SSC, Bank and RRB exams – Shanmugam IAS Academy, Coimbatore.

Get daily current affairs & exam alerts – follow us YouTube WhatsApp Channel Telegram Channel Facebook Page Instagram
Share with friends & study groups
Link to this page from your website / blog (HTML code)
1.  
In a test cross RrYy × rryy, what fraction of the offspring is expected to be wrinkled and green (rryy)?

Correct Answer: A [1/4]

Explanation:

Rr × rr gives ½ rr; Yy × yy gives ½ yy → ½ × ½ = ¼.

2.  
Both parents have blood group AB. Which blood group can their child NOT have?

Correct Answer: B [O]

Explanation:

IᴬIᴮ × IᴬIᴮ gives IᴬIᴬ (A), IᴬIᴮ (AB) and IᴮIᴮ (B); no i allele, so never O.

3.  
A DNA sample has 18 % thymine. Its guanine content is:

Correct Answer: C [32 %]

Explanation:

A = T = 18 % → A + T = 36 % → G + C = 64 % → G = 32 %.

4.  
Statement-basedWhich is/are correct?
I. Incomplete dominance gives a 1 : 2 : 1 phenotypic ratio in F2.
II. The AB blood group is an example of codominance.
III. Independent assortment holds for tightly linked genes.

Correct Answer: C [I and II only]

Explanation:

Linked genes do not assort independently.

5.  
In the F2 of a Tt × Tt cross, what fraction of all the plants is dwarf?

Correct Answer: D [1/4]

Explanation:

Answer: 1/4. Only tt is dwarf: 1 of 4.

6.  
Spot My Mistake"In birds, as in humans, the male decides the sex of the offspring." The error is:

Correct Answer: A [In birds the female (ZW) decides]

Explanation:

Answer: In birds the female (ZW) decides. Birds: ZZ male, ZW female.

7.  
Reverse questionA hormone is a gas, promotes female flowers in cucumber and ripens fruits. It is:

Correct Answer: B [Ethylene]

Explanation:

All three clues point to ethylene.

8.  
True/False drillhow many are TRUE?
I. The light reaction releases oxygen.
II. RuBisCO fixes carbon dioxide.
III. Chlorophyll contains iron.
IV. Xylem vessels are dead cells.

Correct Answer: C [Three]

Explanation:

Chlorophyll contains magnesium; the rest are true.

➤ Full notes, shortcuts and every answer explained – SSC CGL 2026 General Science book (₹149): www.shanmugamiasacademy.in/study-materials/ssc-cgl-general-science

📘 SSC CGL 2026 – General Science (Tier I + Tier II)
Here you get the answer with a one-line explanation. 1,110 original questions with answer key and explanations · mind-maps, notes, tables and shortcuts · Tier I and Tier II practice sets + 3 mock tests
Get the book – ₹149 ₹299 →
Score: 0 Answered: 0 / 0