Fruits Classification Quiz

Fruits

• True fruit - develops from the ovary and its contents
• Accessory fruit - includes the ovary plus other floral parts, like the receptacle, petals, and sepals
• Simple fruit - forms from a single pistil
• Dry fruits - have a dry and hardened coat at maturity
  • Dehiscent fruits - split open to release seeds
    • Legume - formed from a single carpel and splits along both the dorsal and ventral sutures
    • Follicle - formed from one carpel and splits along one suture
    • Capsule - formed from several carpels
    • Silique - a long and slender capsule formed from two carpels
  • Indehiscent fruits - do not open at maturity to release seeds
    • Achene - has a single seed attached to the fruit wall at one point
    • Nut - similar to an achene but with a very thick and hardened wall
    • Samara - has a wing-like outgrowth from the fruit wall
    • Grain - the fruit wall and seed coat are fused
    • Schizocarp - forms from several carpels
• Fleshy fruits - have a soft, fleshy coat at maturity
  • Drupe - one-seeded fruit from a superior ovary (e.g., peach, cherry)
  • Berry - the ovary wall (or its inner portions) becomes enlarged and juicy (e.g., tomato, grape)
    • Hesperidium - a type of berry with a leathery rind (e.g., orange, lemon)
    • Pepo - a type of berry with a hard rind (e.g., watermelon, pumpkin)
  • Pome - forms from a group of fused carpels and is surrounded by the floral tube or receptacle (e.g., apple, pear)
• Aggregate fruit - formed from multiple pistils of a single flower (e.g., raspberry, blackberry)
• Multiple fruit - formed from multiple pistils (and sometimes accessory parts) of many flowers (e.g., pineapple, fig)

Seeds

• Develop after ovules undergo fertilization
• Composed of the seed coat and embryo
  • Embryo - contains the radicle (root) and cotyledons (seed leaves)

Types of Seeds

• Angiosperm seeds - enclosed within an ovary (usually within a fruit)
  • Include flowers, fruits, and endosperm
• Gymnosperm seeds - not enclosed by fruit, often found on scales or leaves.
  • Includes cones

Monocot Seeds

• Have a single cotyledon
  • Seed coat - membranous and fused with the fruit wall ("pericarp")
  • Endosperm - stores food
  • Aleurone layer - proteinous layer separating the endosperm and embryo
  • Scutellum - shield-shaped cotyledon
  • Embryo - small and located in a groove
  • Embryonal axis - has two ends: plumule (shoot tip) and radicle (root tip)
  • Coleoptile - sheath enclosing the plumule
  • Coleorhiza - sheath enclosing the radicle

Dicot Seeds

• Have two cotyledons
  • Seed coat - outermost covering, with two layers: testa and tegmen
  • Hilum - scar on the seed coat where it was attached to the fruit
  • Micropyle - small pore above the hilum
  • Embryo - includes the embryonal axis and two cotyledons
  • Endosperm - food-storing tissue formed by double fertilization
  • Cotyledons - fleshy and store food reserves
  • Plumule and radicle - located at the two ends of the embryonal axis

Seed & Fruit Dispersal

• Wind - light seeds are carried by wind
• Animals - birds and ants distribute seeds
• Water - seeds with trapped air float and are dispersed by water
• Other mechanisms - cultivation by humans

Germination

• The process by which a dormant seed begins to grow into a seedling
• Some seeds require a period of dormancy before germination
• Stages of germination:
  • Imbibition - seed absorbs water and swells
  • Respiration - changes from anaerobic to aerobic respiration
  • Effect of light - some seeds are photoblastic (need light) or non-photoblastic (light has no effect)
  • Mobilization of reserves - stored starch, protein, or fats are utilized
  • Development of the embryo axis - cells grow and divide to form a seedling

Modes of Germination

• Epigeal germination - the cotyledons emerge above the soil
• Hypogeal germination - the cotyledons remain below the soil

Factors Affecting Germination

• Internal factors
  • Embryo maturity
  • Presence or absence of chemical inhibitors
• External factors
  • Oxygen
  • Water
  • Temperature (optimal range: 5 to 40°C)

### Pharmaceutical and Pharmacological Importance of Fruits and Seeds

• Fruits
  • Angelica (A. archangelica) - treats cold and fever
  • Buckthorn (Rhamnus catharticus) - laxative
  • Cranberry (Vaccinium oxycoccum) - treats candidiasis
  • Cubeb (Piper cubeba) - condiment; treats asthma
  • Mangosteen (Garcinia mangostana) - aids in weight reduction
  • Persimmon (Diospyros virginiana) - astringent, high in beta-carotene and vitamin C
  • Spicebush (Lindera benzoin) - reduces fever when brewed as a tea
  • Tamarind (Tamarindus indica) - laxative
  • Pineapple (Ananas comosus) - contains bromelain (antiplatelet, improves circulation, treats mouth ulcers)
• Seeds
  • Anise (Pimpinella anisum) - relieves indigestion and sinusitis
  • Velvet bean (Mucuna spp.) - treats Parkinson’s disease
  • Strophanthus (Strophanthus spp.) - source of cortisone; heart stimulant
  • Strychnine (Strychnos nox-vomica) - stimulates CNS and relieves paralysis
  • Pumpkin (Cucurbita pepo) - promotes prostate health
  • Oats (Avena sativa) - enhances physical and sexual health
  • Perilla (P. frustescens) - rich in omega-3 fatty acids for cardiac health
  • Evening primrose (Oenothera spp.) - source of gamma-linolenic acid
  • Fenugreek (Trigonella foenum-grecum) - bulking laxative, treats mucus, asthma, and skin inflammation
  • Flax (Linum usitatissimum) - treats atherosclerosis; laxative and for bronchial problems
  • Grape (Vitis vinifera) - antioxidant, improves blood flow to the retina
  • Grapefruit (Citrus paradise) - treats bacterial and fungal infections
  • Horse chestnut (Aesculus hippocastanum) - improves blood flow, reduces varicose veins and leg swelling
  • Java plum (Syzygium cumini) - treats excessive thirst and excretion of sugar in urine
  • Apricot (Prunus armeniaca) - bronchodilator
  • Black currant (Ribes nigrum) - improves skin and reduces dryness
  • Cardamom (Elettaria cardamomum) - has antibiotic properties and treats colds
  • Celery (Apium graveolens) - antioxidant, sedative properties
  • Borage (Borago officinalis) - contains gamma-linolenic acid (GLA)
  • Chaulmoogra (Hydnocarpus spp.) - treats eczema, psoriasis, and leprosy
  • Chia (Salvia columbariae) - enhances endurance and treats eye irritation
  • Chocolate (Theobroma cacao) - elevates serotonin, improves mood
  • Cola (C. nitida/ acuminate) - lessens fatigue (contains caffeine and theobromine)