A Atom
B Cell
C Tissue
D Organ
Explanation: The cell is the basic structural and functional unit of all living organisms.
A Ribosome
B Golgi apparatus
C Mitochondria
D Endoplasmic reticulum
Explanation: Mitochondria generate most of the cell\'s supply of ATP through oxidative phosphorylation.
A Plant cell
B Animal cell
C Prokaryotic cell
D Eukaryotic cell
Explanation: Prokaryotic cells lack a membrane-bound nucleus; their genetic material floats freely in the cytoplasm.
A Meiosis
B Mitosis
C Binary fission
D Cytokinesis
Explanation: Mitosis produces two genetically identical daughter cells from a single parent cell.
A Mitochondria
B Ribosome
C Cell wall
D Cell membrane
Explanation: Plant cells have a rigid cell wall made of cellulose that provides structural support.
A G1 phase
B S phase
C G2 phase
D M phase
Explanation: During the S (synthesis) phase, DNA is replicated so each daughter cell receives a complete copy.
A Glucose
B Amino acid
C Starch
D Fatty acid
Explanation: Starch is a polysaccharide made of many glucose units and serves as energy storage in plants.
A DNA polymerase
B Helicase
C Ligase
D Primase
Explanation: Helicase breaks the hydrogen bonds between base pairs, unwinding the DNA double helix.
A Cytosine
B Guanine
C Thymine
D Uracil
Explanation: In DNA, Adenine always pairs with Thymine through two hydrogen bonds.
A DNA -> Protein -> RNA
B RNA -> DNA -> Protein
C DNA -> RNA -> Protein
D Protein -> RNA -> DNA
Explanation: The central dogma states that DNA is transcribed to RNA, which is then translated to protein.
A Lysosome
B Ribosome
C Peroxisome
D Vacuole
Explanation: Ribosomes are the sites of protein synthesis, translating mRNA into polypeptide chains.
A Phenotype
B Genotype
C Allele
D Locus
Explanation: Genotype refers to the complete set of genes an organism carries.
A Mitosis
B Fertilization
C Gamete formation
D Growth
Explanation: Alleles for each trait separate so that each gamete carries only one allele for each gene.
A Monohybrid cross
B Dihybrid cross
C Test cross
D Back cross
Explanation: A test cross involves crossing an individual with dominant phenotype but unknown genotype with a homozygous recessive individual.
Explanation: Blood group O has no A or B antigens, making it safe to transfuse to any blood group.
A Nephron
B Neuron
C Alveolus
D Villus
Explanation: Each nephron filters blood and forms urine through filtration, reabsorption, and secretion.
A Glucagon
B Insulin
C Adrenaline
D Thyroxine
Explanation: Insulin promotes the uptake and storage of glucose, thereby lowering blood sugar levels.
A Bronchus
B Trachea
C Alveolus
D Larynx
Explanation: Alveoli are tiny air sacs with thin walls where oxygen and carbon dioxide are exchanged.
A Vitamin A
B Vitamin B12
C Vitamin C
D Vitamin K
Explanation: Vitamin K is necessary for the synthesis of clotting factors in the liver.
A Thyroid
B Pancreas
C Liver
D Salivary gland
Explanation: The liver performs over 500 functions including bile production, detoxification, and metabolism.