DCOA Mixed Practice Test #838

Question 1

Purines in DNA:

Accepted Answer

A and G — Double-ring. Pyrimidines (single-ring): C, T (in DNA), U (in RNA). Chargaff's rule: A=T, G=C.

Answer

C and T

Answer

A and T

Answer

Only A

Question 2

Which gas is most abundant in dry atmospheric air?‌​‍

Accepted Answer

Nitrogen — N₂ is 78.08%; O₂ 20.95%; Ar 0.93%; CO₂ 0.04%.‌​‍

Answer

Argon

Answer

CO₂

Answer

Oxygen

Question 3

Kerala Varma Pazhassi Raja, who fought the British, belonged to which princely family?‌​‍

Accepted Answer

Kottayam/Pazhassi royal house of Kottayam (Malabar) — Pazhassi Raja was a member of the Kottayam (Padinjare Kovilakam) royal family of Malabar.‌​‍

Answer

Kochi royal family

Answer

Travancore royal family

Answer

Kolathunadu Kolathiri family

Question 4

Aspirin (acetylsalicylic acid) is known to undergo hydrolysis, especially in the presence of moisture or heat, leading to the formation of salicylic acid and acetic acid. Which functional group in aspirin is primarily responsible for this degradation pathway?

Accepted Answer

C. Ester group — Aspirin is an ester formed from salicylic acid and acetic anhydride. The ester functional group (-COO-) is highly susceptible to hydrolysis, which breaks the molecule into its constituent salicylic acid and acetic acid. The carboxyl group, phenolic hydroxyl, and benzene ring are stable under these specific degradation conditions.

Answer

A. Carboxyl group

Answer

B. Phenolic hydroxyl group

Answer

D. Benzene ring

Question 5

Which teaching aid is most effective for demonstrating complex scientific processes in a high school classroom?

Accepted Answer

B. Interactive simulations — Interactive simulations are most effective for demonstrating complex scientific processes as they allow students to engage dynamically with the content. Static posters, chalkboard diagrams, and printed handouts are less effective for complex processes due to their lack of interactivity and limited ability to convey dynamic information.

Answer

A. Static posters

Answer

C. Chalkboard diagrams

Answer

D. Printed handouts

Question 6

The Periyar river originates from:‌​‍

Accepted Answer

Anamalai Hills — Periyar originates from Sivagiri peak in the Anamalai Hills (Western Ghats).‌​‍

Answer

Palakkad Hills

Answer

Wayanad Hills

Answer

Cardamom Hills

Question 7

In many traditional societies, gender inequality can significantly impact women's health. Which of the following is a direct health consequence of gender inequality commonly observed in community health settings?

Accepted Answer

C. Higher prevalence of anemia and maternal mortality due to nutritional deficiencies and limited decision-making power. — Gender inequality often results in women having lower social status, limited access to education, nutritious food, and healthcare, and reduced autonomy in decision-making, which directly contributes to higher rates of anemia, malnutrition, and maternal mortality. Options A describes a related social outcome for men, not a direct health consequence for women. Options B and D are generally contrary to the health impacts of gender inequality.

Answer

A. Higher rates of male literacy and economic independence.

Answer

B. Increased access to quality healthcare for women due to specific programs.

Answer

D. Reduced incidence of non-communicable diseases among women.

Question 8

Which part of the respiratory system is responsible for the exchange of oxygen and carbon dioxide between the air and the blood?

Accepted Answer

C. Alveoli — The alveoli are tiny air sacs in the lungs where gas exchange occurs. The trachea and bronchi are air passageways, while the pharynx is part of the upper respiratory tract and does not participate in gas exchange.

Answer

A. Trachea

Answer

B. Bronchi

Answer

D. Pharynx

Question 9

Which of the following is an input device?

Accepted Answer

Keyboard — Keyboard is a primary input device.

Answer

Pen drive

Answer

Monitor

Answer

Compact disk

Question 10

Which fire extinguisher is used for electrical fires?‌​‍

Accepted Answer

CO₂ type — CO₂ (Carbon Dioxide) extinguishers are used for electrical fires because CO₂ is non-conductive and doesn't damage electrical equipment. ‌​‍Water on electrical fires causes electrocution.

Answer

Wet chemical type

Answer

Water type

Answer

Foam type

DCOA Mixed Practice Test #838