Question

A large number of lysosomes are found in
A. Angiosperm flower
B. Bacterial cell
C. Blue-green algae
D. Animal cell

Answer 1

Hint: In eukaryotic cells, several membrane-bound organelles are present. One example is of lysosomes. Lysosomes are spherical sacs containing hydrolytic enzymes and the main function of lysosomes is to digest biomolecules. It is used to break cellular wastes with the help of enzymes.

Complete answer: The area within the membrane is known as the lumen and it primarily contains hydrolytic enzymes. The lumen has a pH ranging from 4.5-5.0 and a size of lysosome varies from 0.1 um to 0.6 um. Lysosomes degrade undesirable wastes both from inside and outside of the cell but at times, the lysosomes cause autolysis, i.e. disintegration of itself by degrading its cell membrane by the action of enzymes. Main functions involve digestion and wastes removal. Lysosomal enzymes are made in the rough endoplasmic reticulum. These enzymes are then transferred to Golgi apparatus in which enzymes are packaged into vesicles and are mixed with mannose-6-phosphate converting them into acidic vesicles. The membrane of a lysosome invaginates and creates vacuoles or pouches. Wastes and foreign particles are engulfed inside the pouch by the process known as endocytosis. The internal wastes of a cell are digested via autophagocytosis. Any mutation in nuclear genes causes a group of diseases known as lysosomal storage diseases which leads to the death of cells or other forms of cancer or disorders. Lysosomes are a characteristic feature of an animal cell that plays an important role in metamorphosis, removal of wastes, scavenging and digestion. Lysosomes are largely found only in eukaryotic animal cells.
Hence, option D is the correct answer.

Note: It is a membrane-bound organelle that destroys invading bacteria and viruses. It is known to contain 60 different enzymes. It was discovered and named by Belgian biologist Christian de Duve. Enzymes of the lysosomes are synthesised in the rough endoplasmic reticulum.