Cell Structure And Function Test 3

• The plasma membrane, also known as the cell membrane, regulates the transportation of materials entering and exiting the cell.
• This bi-layered structure is "selectively permeable," meaning it allows certain substances to pass while blocking others, to maintain the cell's internal balance.
• Therefore, the correct answer is B, "Selectively Permeable".

• The nucleus of a cell contains a type of fluid that sustains its internal structure.
• This fluid, known as "Nucleoplasm", houses the chromosomes and nucleoli and is enclosed by a nuclear membrane.
• The nucleoplasm plays a fundamental role in the transportation of materials between the nucleus and the cytoplasm.
• Hence, the correct answer is B, "Nucleoplasm".

• The basic unit of life that is capable of all biological functions is a "Cell".
• A bacterial colony is a cluster of the same type of bacteria, but is not the smallest unit of life.
• The Chloroplast is a cellular organelle, not an independent unit of life.
• DNA is the genetic material inside a cell, but cannot function independently.
• Therefore, the correct answer is B, "Cell".

• Cellular organelles such as the mitochondria, nucleus, and chloroplast are all enclosed by membranes.
• These membranes serve to protect the organelles and regulate the movement of substances in and out.
• Therefore, all the options mentioned are correct.
• Thus, the right answer is D, "All of these".

• Chromoplasts, due to their vibrant colors, attract pollinators like butterflies, facilitating the pollination process.
• Chloroplasts and Leucoplasts, on the other hand, do not play a direct role in pollination.
• Therefore, the correct answer is B, "Chromoplast".

• The Endoplasmic Reticulum has various functions within the cell, including drug detoxification, steroid synthesis, and impulse transmission.
• However, providing rigidity is not a function of the Endoplasmic Reticulum, as that is attributed to the cell wall.
• Hence, the correct answer is D, "Rigidity".

• The eukaryotic nucleus usually contains the nucleolus, chromatin, and nucleosome.
• Circular DNA, however, is a feature of prokaryotic cells, making it an exception for eukaryotic nuclei.
• Therefore, the correct answer is D, "Circular DNA".

• Among the mentioned organelles, mitochondria uniquely house their own DNA, hence enabling its self-replication.
• The Golgi complex, Lysosomes, and Ribosomes do not contain DNA.
• Therefore, the correct answer is C, "Mitochondria".

• The Golgi Complex is characterized by two distinct faces, the cis or forming face (which is convex) and the trans or maturing face (which is concave).
• The cis face is oriented towards the nucleus while the trans face is oriented towards the plasma membrane.
• Consequently, the correct answer is B, "Convex Surface".

• Both the mitochondria and the nucleus are double membrane-bound organelles.
• Plastids, found in plant cells, also possess a double membrane.
• Conversely, Centrioles are composed of microtubules and do not have a membrane structure.
• Hence, the correct answer is C, "Centriole".

• Mitochondria are unique as they contain their own DNA, allowing them to replicate independently within the cell to meet the requirements for increased energy production.
• Ribosomes, lysosomes, and centrioles, while crucial to cellular function, do not possess this self-replicating property.
• As a result, the correct choice is D, "Mitochondria".

• rDNA synthesis, an essential process for protein production, is known to occur in the central area of the nucleolus.
• The peripheral area of the nucleolus, nucleus, and cytoplasm are not typically associated with rDNA synthesis.
• Thus, the correct answer is B, "Central area of Nucleolus".

• Phagocytes are responsible for engulfing and digesting harmful particles, a process that requires a large number of lysosomes.
• Goblet cells, epithelial cells, and lymphocytes, while important in their respective functions, do not typically have a high concentration of lysosomes.
• Consequently, the right answer is A, "Phagocytes".

• The Smooth Endoplasmic Reticulum (SER) is significantly involved in lipid metabolism, including the synthesis of steroids.
• It does not actively facilitate aerobic respiration, conduct intracellular digestion, or transport proteins.
• Therefore, the correct choice is C, "Synthesizing steroids".

Think about the physical structures you would find in a plant cell that are absent in animal cells. The cell wall, unique to plant cells, provides additional support and structure.

The plasma membrane, encapsulating cells, is chiefly composed of lipids and proteins. Proteins make up 60-80% of the composition, while lipids contribute to 20-40%. Therefore, the correct answer is C, "20-40%".

Crista, predominantly residing in mitochondria, plays a key role in energy production. It is primarily composed of lipoproteins. Thus, the correct answer is C, "Lipoproteins".

The Golgi apparatus plays a crucial role in the modification, sorting, and packaging of proteins for secretion. It is involved in the addition of carbohydrates to proteins, a critical step in the formation of glycoproteins. Hence, the correct choice is B, "Golgi Apparatus".

The cell membrane is a vital structure that regulates the movement of substances in and out of all organisms' cells. This membrane is primarily composed of Proteins and Phospholipids. While Cellulose is a component of the plant cell wall, not the cell membrane. Thus, the correct answer is D, "Proteins and Phospholipids".

The cytoplasm is a complex mixture of substances dissolved in water, containing organelles, the nucleus, and a vast array of solutes. When all organelles are removed, the remaining part of the cytoplasm is referred to as Cytosol. Protoplasm refers to the complete content within the cell membrane, including the cytoplasm and nucleus. Therefore, the correct answer is C, "Cytosol".

• There are two types of cells, Prokaryotic and Eukaryotic. The key difference between them is the presence of a nucleus and other membrane-bound organelles.
• Prokaryotic cells, which lack these structures, are primarily found in bacteria.
• Virus, being non-cellular infectious agents, do not fit into either category, while fungi and algae are eukaryotes.
• Hence, the correct answer is A, "Bacteria".

• The key characteristic of certain organelles is their ability to replicate independently, facilitated by their own DNA.
• Mitochondria possess this feature, enabling them to duplicate as needed to fulfill the cell's energy requirements, primarily ATP production.
• Contrastingly, Endoplasmic Reticulum, Ribosomes, Lysosomes, and Golgi Apparatus lack this self-replication ability.
• Consequently, the correct choice is D, "Mitochondria".

• While living cells contain both living and non-living components, the cell wall is a non-living component.
• Protoplasm refers to the living part of a cell, which includes the cytoplasm, nucleus, and organelles such as Ribosomes, Lysosomes, Golgi Apparatus, and Endoplasmic Reticulum.
• The cell wall, however, does not possess the characteristics of living entities.
• Hence, the correct answer is A, "Cell wall".

• Certain organelles are involved in oxygen production through photosynthesis, a process primarily taking place within the chloroplasts.
• During the light reactions of photosynthesis, chloroplasts generate oxygen.
• Plastids, the nucleus, and peroxisomes do not share this oxygenic characteristic.
• Therefore, the correct choice is C, "Chloroplast".

• Oxygen consumption in a cell primarily occurs in the mitochondria, where it serves as the final electron acceptor in the electron transport chain.
• This process, along with the formation of acetyl CoA and the Krebs cycle, also result in carbon dioxide production, giving mitochondria the additional label of carbon dioxide-producing organelles.
• Nucleus, ribosome, and peroxisome do not exhibit this oxygen-consuming functionality.
• Thus, the correct answer is A, "Mitochondrion".

• The term 'cytosol' is used to describe the soluble part of the cytoplasm.
• Cisternae, on the other hand, refers to the membranes that separate the endoplasmic reticulum's content from the cytoplasmic material.
• Endocytosis is a process and not a component of the cytoplasm.
• Therefore, the correct answer is B, "Cytosol".

• Ions play a pivotal role in many cellular processes, including the attachment of ribosome subunits.
• Specifically, Mg ions are critical for this attachment process.
• Na ions and Ca ions do not have a known role in ribosome subunit attachment.
• Hence, the correct answer is C, "Mg ions".

• The plasma membrane of a cell is primarily composed of proteins and lipids.
• While proteins make up 60 to 80% of the membrane content, phospholipids come second in abundance.
• Although intrinsic proteins, sterols, and carbohydrates are present, they do not surpass phospholipids in quantity.
• Hence, the correct answer is C, "Phospholipids".

• Tay-Sachs disease is a storage disorder caused by the abnormal accumulation of substances inside nerve cells.
• Specifically, it is due to the accumulation of lipids, not proteins or carbohydrates.
• This lipid accumulation results from a deficit in lipid-degrading enzymes.
• Therefore, the correct choice is C, "Accumulation of Lipids".

• Certain cellular structures are not enclosed within a membrane, differentiating them from those that are.
• The ribosome, the cytoskeleton, and the centriole are examples of such organelles.
• They perform essential functions in the cell, despite not being membrane-bound.
• Consequently, the correct answer is D, "All of these".

• The cell wall is a unique structure found in certain types of organisms, providing rigidity and support.
• It is a distinguishing feature of plant cells, where it provides structural stability.
• Similarly, algae and fungi also possess cell walls that aid in their survival and growth.
• Contrarily, animal cells do not have cell walls, differentiating them from plants, algae, and fungi.
• Therefore, the correct answer is D, "All of these".