MCQs

Explanation
The cell is the smallest unit of life . Cells are called ‘ structural ’ and ‘ functional ’ units for a reason. Cells are made of molecules which are in turn made up of atoms . “ Cell is the unit of LIFE ” is that a cell is the smallest living entity in a living system.

Explanation
The backbone of DNA consists of alternating deoxyribose sugar and phosphate groups , linked by phosphodiester bonds. Key Information : Sugar-Phosphate Backbone : Provides structural stability to the DNA double helix. Directionality: 5’ (phosphate) to 3’ (sugar) orientation. Nitrogenous Bases (A, T, C, G) : Attached to the sugar but not part of the backbone. Form hydrogen bonds to create base pairs (A-T, C-G).

Explanation
Nucleic acids (DNA/RNA) are present in: Nucleus : Contains genomic DNA (eukaryotic cells). Mitochondria : Have their own mtDNA (vital for energy production). Chloroplasts (in plants/algae): Contain cpDNA for photosynthesis-related functions.

Explanation
The modern periodic table is arranged by increasing atomic number (number of protons). This arrangement resolves inconsistencies in earlier tables and groups elements with similar properties together.

Explanation
ATP (Adenosine Triphosphate) is called the energy currency of the cell because it stores and provides energy for cellular activities. It releases energy when converted to ADP (Adenosine Diphosphate), which is then recycled back into ATP through cellular respiration.

Explanation
Boyle’s Law describes the inverse relationship between the pressure (P) and volume (V) of a given mass of gas at constant temperature (isothermal conditions): P ∝ 1/V or PV = constant Key Points : Conditions : Fixed mass and temperature (no chemical reactions). Example : Compressing a syringe (volume ↓ → pressure ↑).

Explanation
The increase in length (or volume) of solids when heated is specifically called thermal expansion . Key Information : Thermal Expansion : Occurs due to increased atomic vibrations with temperature. Linear expansion : Change in length (e.g., railroad tracks expanding in summer). Volumetric expansion : Change in 3D dimensions (e.g., mercury in thermometers).

Explanation
Methane is the simplest of saturated hydrocarbons with a chemical formula CH4. It consists of four hydrogen atoms and one carbon atom. It is the simplest alkane .

Explanation
Cholesterol is a vital precursor in the biosynthesis of: Vitamin D : Cholesterol converts to 7-dehydrocholesterol in the skin, which forms vitamin D₃ under UV light. Steroid Hormones : Cholesterol is the backbone for : Sex hormones (testosterone, estrogen, progesterone). Adrenal hormones (cortisol, aldosterone).

Explanation
The cost of 8 Books is 950. One Book Cost = 950/8 =118.75 Then the cost of 12 books is = 12 × 118.5                                       = RS. 1425 SH5-9-2023

Explanation
Solve: =√16+9  =√(25) =5 SH5-9-2023

Explanation
Fractions with the same denominator are called like fractions . Example: ½, 3/2, 5/2, 7 /2 etc Sh5-9-2023

Explanation
area of rectangle garden=1500m² length  of garden=500m width=x area of rectangle = length *breadth =1500=500*x x=1500/500 x=3m SH5-9-2023

Explanation
ASF Act 1975  came into effect, it repealed the  Airports Security Force Ordinance, 1975 ...................... ASF Pakistan The Airport Security Force (Pakistan) (ASF) is part of the  Aviation Division (Pakistan)  ASF  is responsible for protecting the  airports and the facilities  and the planes (on-ground or in-air). .....................  ASF act was repealed after the promulgation of Federal Investigation Agency  Act, 1974 The Pakistan Special Police Establishment,   1948, and The Special Police and Provincial Police (Amalgamation)  Order 1962   act was repealed after the promulgation of the Federal Investigation Agency Act, 1974

Explanation
The OPCW was awarded the  Nobel Peace Prize in 2013 . Its headquarters are located in  The Hague, Netherlands . .................. The  ultimate aim of the OPCW  is  to achieve a world permanently  free of chemical weapons  and to contribute to i nternational security and stability,   general and complete disarmament, and global economic development . .............. The Hague is a city on the North Sea coast of  the western Netherlands.  The Hague Province of  South Holland ....................... The OPCW is not a  United Nations (UN) organisation ,  Pakistan  is an active member of the OPCW

Explanation
HCF Stand for Highest Common factor So the HCF of 60 and 72 is 2 × 2 × 3 which is 12. .......... T he lowest common multiple is found by multiplying all the factors which appear in either list ........... So the LCM of 60 and 72 is 2 × 2 × 2 × 3 × 3 × 5 which is 360. SH5-9-2023

Explanation
ASF headquarters is located in Karachi. ASF was established in  in  1976  under the Airports Security Force  Act LXXVII of 1975 from  2013 under  the umbrella of Cabinet Secretariat, an Aviation Division was created.

Explanation
NACTA was established in   2009 NACTA stands for National Counter Terrorism Authority NACTA is a Pakistani internal security organization responsible for making counter-terrorism and counter-extremism policies and strategies.  NACTA  was created  as an Administrative Wing within the  Ministry of Interior  The headquarters is in  Islamabad,  Pakistan   The NACTA 2013 Act sets up the framework of the organization ND31-8-2023

Explanation
HRC stands for: Human Rights Commission The United Nations Human Rights Council ( UNHRC ) is a United Nations body whose mission is to promote and protect human rights around the world Formation : 15 March 2006 The Council has 47 members elected for staggered three-year terms on a regional group basis. The headquarters of the Council are at the United Nations Office Geneva in Switzerland . ND-31-8--2023