Cell Structure — Set 2
Biology · कोशिका संरचना · Questions 11–20 of 60
Which organelle is involved in the synthesis of lipids and steroid hormones?
Correct Answer: C. Smooth ER
The Smooth Endoplasmic Reticulum is responsible for producing essential lipids and hormones like testosterone. It lacks the ribosomes that give the 'Rough' ER its bumpy appearance. This organelle is particularly abundant in cells that secrete oils or hormones.
The 'Tonoplast' is the membrane surrounding which cellular structure?
Correct Answer: A. Vacuole
The tonoplast regulates the movement of ions and materials into the large central vacuole of plant cells. It helps maintain the turgor pressure necessary for plant rigidity. This membrane is semi-permeable and vital for cellular homeostasis.
Which pigment is primarily responsible for the green color of plants and is found in chloroplasts?
Correct Answer: C. Chlorophyll
Chlorophyll captures light energy from the sun to drive the process of photosynthesis. It is located within the thylakoid membranes inside the chloroplasts. Magnesium is the central metal ion present in the chlorophyll molecule.
Which cellular component is known for having a 'cis' face and a 'trans' face?
Correct Answer: C. Golgi Apparatus
The 'cis' face of the Golgi apparatus receives vesicles, while the 'trans' face ships them out. This polarity is essential for the directional flow of materials during protein modification. It consists of flattened sacs known as cisternae.
Which scientist discovered the presence of the nucleus in the plant cell in 1831?
Correct Answer: C. Robert Brown
Robert Brown was the first to identify the nucleus as a constant component of living cells. He made this discovery while studying orchids under a microscope. This find was a crucial step in the development of the cell theory.
What is the primary material that makes up the cell wall of most fungi?
Correct Answer: A. Chitin
Chitin is a tough, nitrogen-containing polysaccharide that provides structural support to fungal cells. It is chemically similar to cellulose but much more durable and resistant to decay. Chitin is also found in the exoskeletons of insects and crustaceans.
Which part of the cell is described as the 'kitchen of the cell'?
Correct Answer: D. Chloroplast
Chloroplasts are called the kitchen because they manufacture food (glucose) using sunlight. This process, known as photosynthesis, is fundamental to life on Earth. They are found in plant cells and some protists like algae.
Which organelle contains digestive enzymes that break down waste and cellular debris?
Correct Answer: C. Lysosome
Lysosomes are spherical sacs filled with hydrolytic enzymes that function at an acidic pH. They perform 'autophagy' by recycling damaged organelles and protecting the cell from invaders. They are often nicknamed 'suicide bags' for their role in programmed cell death.
In which part of the cell does the process of 'Glycolysis' occur?
Correct Answer: B. Cytoplasm
Glycolysis is the initial stage of glucose breakdown and takes place in the cytosol of the cytoplasm. It does not require oxygen and produces a small amount of energy in the form of ATP. The products of glycolysis then move into the mitochondria for further processing.
Which structure connects the cytoplasm of adjacent plant cells through small channels?
Correct Answer: C. Plasmodesmata
Plasmodesmata are microscopic channels that traverse the cell walls of plant cells. They allow for the direct exchange of water, nutrients, and signaling molecules between cells. This connection integrates the entire plant into a functional unit.