Biology: Ultra structure of Cells Online Quiz

Exocrine gland cells of the pancreas synthesize and secrete large quantities of digestive enzymes (proteins). Therefore, they require a highly developed rough endoplasmic reticulum and Golgi apparatus to process, package, and target these proteins for secretion.

Prokaryotic cells, which lack a nucleus and membrane-bound organelles, reproduce asexually through a process called binary fission. Eukaryotic cells divide their nucleus via mitosis or meiosis.

Palisade mesophyll cells are located in the upper region of leaves and are the primary site of photosynthesis. Consequently, they are packed with a high density of chloroplasts to maximize light absorption.

Light microscopes use visible light and lenses to magnify specimens, resulting in a much lower resolution (limit of about 200 nm) compared to electron microscopes, which use electron beams and have a much higher resolution (limit of about 0.1 nm).

Eukaryotic cells contain larger 80S ribosomes in their cytoplasm and on the rough endoplasmic reticulum, whereas prokaryotic cells contain smaller 70S ribosomes. Although eukaryotic organelles like mitochondria and chloroplasts contain 70S ribosomes, 80S ribosomes are the defining cytoplasmic ribosomes of eukaryotes.

Animal cells may contain small, temporary vacuoles, but they do not have the large, permanent central vacuole characteristic of plant cells. Ribosomes, lysosomes, and DNA are all present in animal cells.

The nucleus contains the cell's genetic material (DNA), making it the site for DNA replication and transcription. Photosynthesis occurs in chloroplasts, cellular respiration occurs primarily in mitochondria, and protein synthesis (translation) occurs on ribosomes in the cytoplasm.

In eukaryotic cells, DNA replication takes place inside the nucleus, not in the cytoplasm. Metabolic reactions, organelle suspension, and translation (protein synthesis) by free ribosomes all occur within the cytoplasm.

Chloroplasts are the sites of photosynthesis and are found in plant cells (and some algae) but not in animal cells. Peptidoglycan cell walls are found in bacteria, small vacuoles can be found in animal cells, and both plant and animal cells have a nucleus.

The cell wall of most prokaryotes (specifically bacteria) is composed of peptidoglycan (murein). Plant cell walls are made of cellulose, while phospholipids form the cell membrane.

Mitochondria are the powerhouses of the cell, where aerobic cellular respiration takes place to convert biochemical energy from nutrients like glucose into adenosine triphosphate (ATP).

Chloroplasts carry out photosynthesis in plant cells, using light energy, water, and carbon dioxide to synthesize glucose. Mitochondria, conversely, break down glucose to produce ATP.

Specialized structures within a cell that perform specific functions are called organelles (literally 'little organs'). Examples include the nucleus, mitochondria, and ribosomes.

Both plant and animal cells are eukaryotic because they contain a membrane-bound nucleus and other membrane-bound organelles. This distinguishes them from prokaryotic cells, such as bacteria.

Cellulose is a complex carbohydrate that provides structural support and rigidity, and it is the primary component of plant cell walls. It is not found in the cell membrane, cytoplasm, or nucleus.

Lysosomes are membrane-bound organelles containing hydrolytic enzymes that break down waste materials, foreign debris, and worn-out cellular components.

Plant cells typically contain a single, large central vacuole that stores water and maintains turgor pressure to keep the plant upright. In contrast, animal cells may contain multiple small, temporary vacuoles, but not a large central one.

The Golgi apparatus is responsible for modifying, sorting, and packaging proteins received from the rough endoplasmic reticulum. The nucleus houses genetic material, while the smooth and rough ER are primarily involved in lipid and initial protein synthesis, respectively.

The cell membrane (or plasma membrane) is selectively permeable, meaning it regulates the passage of substances into and out of the cell. The cell wall provides structural support but is fully permeable, while the nucleus and mitochondria have different metabolic and genetic functions.

Ribosomes are the cellular structures responsible for protein synthesis, where they translate messenger RNA (mRNA) into polypeptide chains. Respiration occurs in mitochondria, photosynthesis in chloroplasts, and DNA replication in the nucleus.

Chloroplasts contain chlorophyll, which absorbs sunlight to drive photosynthesis, converting carbon dioxide and water into glucose and oxygen. Respiration is performed by mitochondria, and protein synthesis is performed by ribosomes.

Mitochondria are responsible for aerobic cellular respiration, which converts biochemical energy from nutrients into adenosine triphosphate (ATP). Photosynthesis occurs in chloroplasts, and protein synthesis is carried out by ribosomes.

Ribosomes (such as 70S ribosomes in prokaryotes, mitochondria, and chloroplasts) are macromolecular complexes of RNA and proteins and do not possess a surrounding lipid membrane. The nucleus, mitochondria, and chloroplasts are all bound by double membranes.

Eukaryotic cells store their primary genetic material inside a membrane-bound nucleus, whereas prokaryotic cells lack a nucleus and keep their DNA in an unbound nucleoid region. This distinction is one of the defining differences between eukaryotes and prokaryotes.