Cell Structure & Function — Part 1: 40 MCQs with Explanations

Mitochondria produce ATP through cellular respiration, providing energy for cellular functions.

Hemoglobin is a protein in red blood cells that binds to oxygen for transport throughout the body.

The S (synthesis) phase is when DNA is replicated to form sister chromatids.

Cellulose forms the cell wall in plants and provides structural support.

Fungi have cell walls composed of chitin, unlike plants which have cellulose.

In sickle cell trait, both normal and sickle-shaped hemoglobin are expressed (heterozygous advantage).

Bacteria lack a true nucleus and membrane-bound organelles, making them prokaryotic.

Translation occurs at the ribosome, where tRNA brings amino acids to match the mRNA codons.

Insulin is secreted by the beta cells of the pancreas, not the liver.

The neuron (nerve cell) is specialized for transmitting electrical and chemical signals.

Sister chromatids separate during anaphase II, similar to mitosis.

Glycolysis occurs in the cytoplasm and splits glucose into two pyruvate molecules.

Phagocytosis ("cell eating") is the engulfment of large solid particles by the cell membrane.

The Krebs cycle (citric acid cycle) takes place in the mitochondrial matrix.

Binary fission, common in bacteria and amoeba, results in two equal daughter cells.

Erythropoietin (EPO) is produced by the kidneys and stimulates RBC production in bone marrow.

Cellulose microfibrils provide strength and structure to the primary plant cell wall.

Ribosomes, either free or bound to ER, assemble amino acids into proteins.

The Golgi apparatus modifies proteins and lipids and packages them into vesicles.

Osmosis is the passive movement of water across a selectively permeable membrane.

Peptidoglycan (murein) is a polymer unique to bacterial cell walls, providing structural strength.

tRNA (transfer RNA) has an anticodon and carries a specific amino acid to the ribosome.

The photolysis (splitting) of water occurs in the thylakoid lumen, associated with the oxygen-evolving complex of photosystem II located on the thylakoid membrane.

As outlined in the cell structure syllabus, the Golgi apparatus (or Golgi complex) is responsible for modifying, sorting, and packaging proteins for secretion.

Prokaryotes, such as bacteria, often contain small circular DNA molecules called plasmids, which are not typically found in the nucleus of eukaryotic cells.

The immunity section of the syllabus covers specific immune mechanisms, which primarily involve lymphocytes (B cells and T cells).

The syllabus on coordination and control describes the neuron's structure, including the axon which is often surrounded by an insulating myelin sheath formed by Schwann cells.

The correct order of the cell cycle phases is Interphase (G1, S, G2) followed by the Mitotic (M) phase.

The fluid mosaic model, proposed by Singer and Nicolson, describes the plasma membrane as a fluid lipid bilayer with embedded proteins.

The smooth ER (SER) lacks ribosomes and is involved in the synthesis of lipids, steroids, and detoxification of drugs and poisons.

Neutrophils are a type of white blood cell (phagocyte) that engulfs and digests pathogens through phagocytosis.

Glycolysis, the first step of cellular respiration, occurs in the cytoplasm (cytosol) of the cell.

Type O individuals lack A and B antigens on their red blood cells, so their blood will not be agglutinated by the recipient's antibodies.

During metaphase, chromosomes line up at the equator (metaphase plate) of the cell, attached to spindle fibers.

Mitochondria are membrane-bound organelles found in both plant and animal cells, responsible for energy production.

Blood is classified as a connective tissue because it consists of cells suspended in a fluid matrix (plasma) and transports materials throughout the body.

Mitochondria are semi-autonomous organelles with their own DNA and 70S ribosomes (similar to prokaryotes), supporting the endosymbiotic theory.

Crossing over during prophase I of meiosis leads to the exchange of genetic material between homologous chromosomes, creating new combinations of alleles.

Messenger RNA (mRNA) is transcribed from DNA and carries the genetic code to the ribosome for protein synthesis.

The correct hierarchical order is: Cell (basic unit), Tissue (group of similar cells), Organ (group of tissues), Organ System (group of organs).

There are cells in human body called Faggot cells which cause Leukaemia .

Active Transport is the correct answer to “What is called movement of cell against concentration gradient”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

The method of reproduction of new plants by cells instead of seed is known is: Tissue culture .

Division of nucleus is termed as Karyokinesis .

Membrane that separates cytoplasm and nucleus is called Nuclear envelop .

Number of cells that are destroyed in adults by apoptosis are 50 to 70 billion cells .

Biebs that are broke off from cell are called Apoptotic bodies .

Guard cells of stoma are Kidney-shaped .

Fuel used by cells in cellular respiration to get energy is Glucose .

Ingestion of bacteria by certain type of cells is termed as Phagocytosis .

The normal range of the number of white blood cells in a microliter of blood is between 4,500 and 10,000 .

The body of Bacteria is not made of cell.

The life and activities of a cell is controlled by nucleus .

Accumulation of lipid molecules in brain cells lead to mental retardation .

Accumulation of lipid molecules in brain cells lead to mental retardation .

Sickle cell anemia was discovered by Vernon Ingram .

Bean shaped cells in plants are guard cells .

branches of biology and medicine concerned with the structure and function of plant and animal cells is called Cytology .

cell membrane is the correct answer to “Which of the following is a selectively permeable membrane”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

smooth is the correct answer to “Which of the following endoplasmic reticulum has no ribosome on its surface”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

Cell wall is the non living, outermost boundary of all the above cell.

G2 Phase is the correct answer to “In which phase of cell cycle cell organelles are formed”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

Vacuoles are fluid filled sacs surrounded by a membrane called tonoplast .

nucleus is the correct answer to “During the process of cell division which of the following divides first”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

Cell wall is richly impregnated with silica in Baciliariophyta .

The cell wall is usually composed of two overlapping halves called epitheca and hypotheca in Diatoms .

Cell wall is extremely well preserved in fossil specimens in Diatoms .

Empty diatom cells are called Frustule .

Oil body is found in the cells of Diatoms .

Increase in proportion of unsaturated fatty acids. is the correct answer to “Which adaptation is acquired by plants of cooler areas to prevent lipid crystal formation in cell membrane”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

Addition of salts and other solutes from other cells into xylem sap, Lowers. the water potential of the xylem sap.

Stomata open due to Active transport of K+ into the guard cells from the surrounding epidermis.

95% of the cytoplasm of red blood cells is the Hemoglobin .

Transport of minerals from soil to epidermal cells of roots via carrier protein molcules along their concentration gradient is called Facilitated diffusion. .

A pressure created by active secretion of salts and other solutes from other cells into xylem sap is called Root pressure .

The pressure generated when water enters & inflates plant cells is called Pressure potential.

Osmosis is the correct answer to “The movement of water molecules from a region of higher water potential to a region of lower water potential (through membrane)”. Items of this type are drawn from the Cell Structure & Function — Part 1 syllabus of Pakistani competitive exams, where the fact is tested verbatim.

All of these component of cell wall has grreat affinity with water.

The membrane of vacuoles is known as Tonoplast .

In plants, the neighbouring cells are connected with one another by Both A & B .