Compare the sink and the source cells; provide examples for each in your answers

Answer 1

Sink cells and source cells are specialized cells in plants that play different roles in various biological processes.

Sink cells, also known as recipient cells, are the destination sites where substances are transported or stored. They are responsible for the uptake, accumulation, and utilization of nutrients and other metabolites. Sink cells can be found in various plant organs such as roots, developing fruits, storage organs like tubers or bulbs, and reproductive structures like seeds. For example:

1. Developing fruits: The cells in a growing fruit act as a sink where sugars produced in the leaves by photosynthesis are transported and stored to support the fruit's growth and development.
2. Root cells: The cells in the root system of a plant act as a sink for water and mineral nutrients absorbed from the soil, which are then transported to other parts of the plant for utilization and growth.

Source cells, on the other hand, are the sites where substances are produced or synthesized and then transported to other parts of the plant. They supply the plant with energy and building blocks needed for growth, development, and reproduction. Source cells are typically located in photosynthetic tissues such as leaves or green stems. Examples include:

1. Mesophyll cells: Found in the leaf tissue, these cells contain specialized organelles called chloroplasts responsible for photosynthesis. Mesophyll cells synthesize sugars and other organic compounds using light energy, and then transport them to other parts of the plant for storage or utilization.
2. Phloem companion cells: Located alongside sieve elements in the phloem tissue, companion cells provide energy and support to facilitate the transport of sugars and other nutrients throughout the plant. They act as a source for loading sucrose into the phloem for long-distance transport to sink tissues.