(a) Organ and organelle: An organ is a collection of tissues working together to perform a specific function (e.g., heart, brain). An organelle is a subunit within a cell that performs a particular function (e.g., mitochondria, nucleus).
(b) Animal and plant tissues: Animal tissues include epithelial, connective, muscular, and nervous tissues that perform various functions like protection, movement, and communication. Plant tissues include meristematic, permanent, vascular (xylem and phloem), and ground tissues that help with growth, support, and transport.
(c) Xylem and phloem: Xylem transports water and minerals from the roots to the rest of the plant, while phloem transports food, mainly sugars, from the leaves to other parts of the plant.
(d) Epithelial and muscular tissue: Epithelial tissue forms protective layers and is involved in absorption and secretion. Muscular tissue is responsible for body movement and includes skeletal, cardiac, and smooth muscle tissues.
(e) Epidermal and ground tissue: Epidermal tissue forms the outer protective layer of plants, while ground tissue is involved in photosynthesis, storage, and support.
(f) Nervous and connective tissue: Nervous tissue transmits electrical impulses throughout the body, and connective tissue supports, binds, and protects other tissues and organs (e.g., bones, blood).
(g) Root and shoot system: The root system anchors the plant and absorbs water and minerals, while the shoot system consists of the stem, leaves, and flowers, which are involved in growth, photosynthesis, and reproduction.
(h) Vegetative and reproductive part: The vegetative parts of the plant are involved in growth and support (e.g., roots, stems, leaves), while the reproductive parts are responsible for reproduction (e.g., flowers, seeds).