Building Blocks of Life Cell and Tissues — Important Questions

Meristematic tissue

Step 1: Meristematic tissue is found at the growing points of plants, especially at root and shoot tips. Step 2: These tissues consist of actively dividing cells that can multiply indefinitely. Step 3: The cells are small, thin-walled, and have large nuclei with dense cytoplasm. Step 4: They lack intercellular spaces and are compactly arranged to support continuous division. Step 5: This tissue is responsible for the primary growth of plants, making stems longer and roots deeper by adding new cells at the tips.

Transport of water and minerals from roots to leaves

Step 1: Xylem is a conducting tissue that forms part of the plant's vascular system. Step 2: Its primary function is to transport water and dissolved minerals absorbed from the soil by the roots. Step 3: This transport occurs in an upward direction, from roots through stems to leaves. Step 4: The water is essential for photosynthesis and maintaining plant structure through turgor pressure. Step 5: Xylem is located towards the center of the stem and consists of specialized cells that form continuous tubes for efficient water transport.

Cardiac muscle

Step 1: Cardiac muscle is the specialized muscle tissue found exclusively in the heart. Step 2: These muscles show striations (bands) like skeletal muscles but are involuntary like smooth muscles. Step 3: Cardiac muscle fibers are short, branched, and connected by special junctions called intercalated discs. Step 4: They contract and relax rhythmically and continuously without getting tired, from embryonic stage until death. Step 5: This unique property enables the heart to pump blood throughout life without voluntary control, making it essential for circulation.

Protein synthesis

Step 1: Ribosomes are small granular organelles responsible for protein synthesis in cells. Step 2: They read the genetic instructions from messenger RNA (mRNA) and translate them into proteins. Step 3: Ribosomes can be found free in the cytoplasm or attached to the endoplasmic reticulum. Step 4: They link amino acids together in the correct sequence to form proteins according to genetic code. Step 5: Since proteins are essential for all cellular functions, ribosomes are often called 'protein factories' of the cell.