Topic 9 - Plant Nutrition and Reproduction

• photosynthesis


  process carried out in organisms containing chlorophyll. Light energy is used to drive reactions where carbon dioxide and water are used to make glucose and oxygen

  
• chlorophyll


  green pigment present in chloroplasts, which absorbs light energy during photosynthesis

  
• chloroplast


  organelle found in some plant cells. The site of the reactions of photosynthesis

  
• cuticle


  thin layer of waxy material covering the epidermis cells of a plant

  
• epidermis (in plants)


  outer layer of cells of a leaf or other non-woody parts of a plant
• palisade mesophyll


  layer of cells below the upper epidermis in a leaf. The main site of photosynthesis

  
• spongy mesophyll


  layer of photosynthetic cells below the palisade layer in a leaf. Contains air spaces and is the main gas exchange surface

  
• diffusion


  movement of molecules or ions down a concentration gradient
• flaccid


  condition in a plant cell which has lost internal pressure, so that the cytoplasm no longer pushes against the cell wall
• turgid


  description of a plant cell with a high internal pressure, so that the cytoplasm pushes against the cell wall
• guard cells


  pair of specialised cells surrounding a stoma in the epidermis of a leaf. They change shape to open or close the stoma
• stomata


  (singular = stoma) pores in the epidermis of a leaf

  
• root hairs


  specialised cells on the surface of a root that take up water and mineral ions from the soil
• lignin


  woody material present in the cell walls of some plant cells, such as xylem vessels. Provides strength and makes the walls impermeable to water
• xylem


  transport tissue carrying water and minerals up through a plant from the roots
• phloem


  plant transport tissue responsible for moving the products of photosynthesis from the leaves to other parts of the plant
• vascular bundle


  xylem and phloem grouped together in a stem or root

  
• asexual reproduction


  reproduction that does not involve fusion of gametes. New organisms are produced by part of an organism separating from a single parent
• sexual reproduction


  reproduction involving fusion of male and female gametes to form a zygote
• anther


  part of the stamen where pollen grains are produced

  
• pollen


  grain structure in plants that contains the male gamete

  
• stamen


  male reproductive organ in plants, consisting of the anther and a stalk called the filament

  
• pollen tube


  tube that grows from a pollen grain and down through the style to allow the transfer of the male gamete to the ovule for fertilisation

  
• ovary


  In plants: female reproductive structure in the carpel of a flower, which contains ovules

  
• ovule


  structure within the ovary in plants. Cells in the ovules divide by meiosis to produce ova.

  
• stigma


  part of the carpel of a flower which receives the pollen during pollination

  
• style


  part of the carpel of a flower. Stalk connecting the stigma to the ovary, through which the pollen tube grows

  
• radicle


  embryonic root of a plant

  
• plumule


  embryonic shoot of a plant

  
• cotyledons


  seed leaves. May act as food store in seed

  
• dicot


  (dicotyledonous plant) plant with two seed leaves
• fruit


  structure containing a seed or several seeds.Formed from the ovary following fertilisation

  
• seed


  structure that forms from the ovule following fertilisation. Contains the embryo plant and its food store

  
• germination


  sequence of events taking place when the embryo in a seed begins to develop into a young plant

  
• cross-pollination


  transfer of pollen from an anther of one plant to a stigma of a different plant of the same species

  
• self-pollination


  transfer of pollen from an anther to a stigma of the same flower or to another flower of the same plant

  
• pollination


  transfer of pollen from anther to stigma

  
• cutting


  method of producing new plants by taking a piece of a shoot and planting it in compost. An example of asexual reproduction