Fruits seeds and germination nucleus vacuole Single celled

Fruits, seeds and germination

nucleus vacuole Single celled zygote Embryo forms Globular from upper stage part of the zygote Heart shapped stage Fig. 31. 7 a-d, p. 536

seed coat cotyledon embryo’s shoot tip EMBRYO SPOROPHYTE embryo’s root tip cotyledon mature embryo within ovule A fruit (mature ovary) cut open to show seeds (mature ovules). endosperm Capsella Triploid (3 n) tissue provides for rapid production of nutrients and growth hormones for the developing embryo Fig. 31. 7 e -g, p. 536

Three types of seed Dicot: Endosperm is used in formation of cotyledons during seed formation Dicot: Endosperm remains as a food source in the seed for use at germination Monocot: Endosperm is a food source in the seed for use at germination

Storage parenchyma in bean cotyledon • The purple structures are starch grains. • What is this tissue stained with? http: //www. uri. edu/artsci/bio/plant_anatomy/images. html#lab_1

Cross section of the seed coat of a bean Macrosclereids Osteosclereids Macrosclereids: column shaped, longer than wide Osteosclereids: bone shaped, elongated with swollen ends

Correspondence between flower and fruit in the pea plant Stigma Seed Ovule Pericarp Ovary wall Sepal

Types of Fleshy Fruits Simple Single ovary of one flower Aggregate Many ovaries of one flower Multiple Many ovaries of many flowers Pineapple Festival" ©Ann Cecil

Germination involves 4 major processes: 1) Hydration (or imbibition) - Seeds must take up water. A seed will absorb water only if the seed coat and / or other coverings are permeable. Water is absorbed by osmosis, driven by the existence / buildup of high solute concentration in the seed cells. 2) Breaking dormancy which initiates metabolism. 3) Enzyme activation - soon after seed hydration, respiratory enzymes are activated, and food reserves, such as starch, are metabolized to produce the fuel (mostly ATP) for synthesis of other enzymes needed for such growth. 4) Carbohydrate, fat and protein reserves in the cotyledons or endosperm are mobilized to support the renewed development of the embryo.

Nutrient mobilization during germination of barley seed Hordeum vulgare L Maltose The embryo releases hormones called gibberellins as signals to the aleurone, the thin outer layer of the endosperm. The aleurone synthesizes and secretes enzymes that hydrolyze starch

Steeping Adding water, the steeping process, is to start germination. Germination is activated when moisture levels in the barley (12 - 13%) are brought up to 43 45%. The steeped barley requires periods of rest and aeration in order to provide adequate oxygen for germination. Steep cycles last approximately 44 hours.

Brewing A mash of water and malted barley is heated, activating enzymes naturally present in the malted barley, causing it to convert starch into sugar which the brewing yeast can later ferment. The mash is pumped into a brewing vessel where barley husks are filtered out. When the sugary water, "wort" has completely dripped through the husks, absorbing their flavour, the husks are removed and the boil begins. (Husks are sold as cattle feed. ) The boil is where the unique hop flavour is added. Varying the type and quantity of hops is what gives each beer its particular flavour and aroma. After settling, the wort is cooled, then pumped into fermentation tanks where yeast is added. The yeast uses the sugar in the wort to create alcohol and carbon dioxide.

“Michelob ULTRA, the latest brand from Anheuser-Busch, is a smooth, refreshing lager with 95 calories, 4. 2 percent alcohol by volume and 2. 6 grams of carbohydrates per 12 -oz. serving. ” “Michelob ULTRA is brewed using the finest pale two-row and Munich six-row barley, select grains, all-imported hops and a pure cultured yeast strain. ” “The special choice of grains, combined with the extended mash process, produces a smooth, refreshing beer with fewer carbohydrates”