Fundamental Unit of Life (Part II)

Messenger RNA (mRNA) is the specific type of RNA that carries genetic information from the DNA in the nucleus to the ribosomes, where it serves as a template for protein synthesis.

A normal human somatic cell contains 46 chromosomes, which are organized into 23 pairs.

Ribosomes are the cellular machinery responsible for translating mRNA into proteins. They are found in the cytoplasm, either free-floating or attached to the endoplasmic reticulum.

Chlorophyll is a pigment molecule used for photosynthesis, not a membrane-bound organelle. E.R., ribosomes, and mitochondria are all considered organelles.

Both prokaryotes and eukaryotes utilize DNA as their genetic material and rely on ribosomes to synthesize proteins, making both statements A and B correct.

Plant cells are fixed in place by a cell wall, meaning they cannot move. Development in plants relies on cell division, enlargement, and differentiation.

The cell membrane (or plasma membrane) is the biological membrane that separates the interior of all cells from the outside environment, effectively surrounding the organelles within the cytoplasm.

Chromoplasts are a type of plastid responsible for pigment synthesis and storage in plants, providing the red, orange, and yellow colors to fruits and flowers.

Robert Hooke discovered cells in 1665 while examining a thin slice of cork under a primitive microscope.

An egg cell of a hen is a single cell that is large enough to be seen with the naked eye, unlike most other microscopic cells.

Robert Brown discovered the cell nucleus in 1831 while observing the cells of orchid roots.

All cells, whether prokaryotic or eukaryotic, are bounded by a cell membrane (plasma membrane) that regulates the passage of substances in and out of the cell.

Centrioles are cylindrical structures involved in cell division and are typically found in animal cells, but they are absent in most higher plant cells.

Muscle cells require significant amounts of energy for contraction, therefore they contain a very high density of mitochondria to produce the necessary ATP.

Endocytosis is the general process by which cells take in substances from the outside by engulfing them in a vesicle. Phagocytosis is a specific type of endocytosis often referred to as cell eating.

Cell theory states that all living organisms are composed of one or more cells, and that the cell is the basic structural and functional unit of life.

Cytology is the branch of biology concerned with the structure and function of plant and animal cells.

Amoeba is a unicellular organism, meaning it performs all life functions within a single cell. Therefore, it exhibits the cellular level of organization.

DNA fingerprinting is a laboratory technique used to identify individuals by their unique genetic profile, making it a powerful tool in forensic science for solving crimes.

Prokaryotes are organisms without a nucleus or membrane-bound organelles, including bacteria and cyanobacteria. Algae and fungi are eukaryotes. Viruses are not cellular and do not fit either category. The option has a typo: cynobacteria should be cyanobacteria.

Nerve cells (neurons) in the human body are highly specialized and generally do not undergo mitosis or divide once they reach maturity. Other cell types like blood, bone, and muscle cells retain the capacity for regeneration or repair throughout life.

The growth of a multicellular organism from a small plant to a tree is primarily driven by cell division (mitosis), which increases the total number of cells in the organism.

Centrioles are cylindrical structures that play a crucial role in organizing the spindle fibers during cell division (mitosis and meiosis) to ensure proper chromosome separation.

Plastids are organelles responsible for photosynthesis and storage. Since roots are generally underground and do not perform photosynthesis, they typically lack chloroplasts and other plastids.

Viruses are considered acellular because they lack the basic cellular machinery, such as cytoplasm, organelles, and independent metabolic processes, required to be classified as a cell.

Cell sap is the fluid found in the central vacuole of a plant cell. It consists of water, dissolved sugars, salts, and other nutrients.

In unicellular organisms like Amoeba, food vacuoles are responsible for the digestion of food particles, mirroring the function of the digestive system in multicellular organisms.

Lysosomes contain digestive enzymes used to break down waste materials and cellular debris. Damaged cells require high lysosomal activity to clear out broken components or undergo programmed cell death.

Lysosomes are involved in intracellular digestion and the removal of waste products, which is a form of cellular excretion.

Viruses lack the machinery for metabolism and reproduction. They contain only genetic material (nucleic acid, either DNA or RNA) and require the host cell's machinery to replicate.

Bacteria are generally much smaller than eukaryotic cells like those of yeast, fungi, or protozoa, often measuring only a few micrometers in size.

Protoplasm is defined as the living part of the cell, which includes the cytoplasm and the nucleoplasm (the fluid inside the nucleus).

When grapes are placed in distilled water (a hypotonic solution), water enters the cells via osmosis, causing the grapes to swell.

Movement is a physical phenomenon that can be observed in both living things (like animals) and non-living things (like cars or clouds). The other options are biological processes exclusive to living organisms.

Prokaryotes typically possess a single, circular chromosome located in the nucleoid region, unlike eukaryotes which have multiple linear chromosomes.