NW 202 Exam #3 - fruits

Explain how fruit forms and ripens.

Fruits are produced only by flowering plants (angiosperms). Following pollination of the flower, the fertilized ovules develop into seeds while the surrounding ovary wall forms the fruit tissue, or pericarp.

What causes an ovary to develop into a fruit?

The ovary surrounding the ovules develops into a fruit once fertilized

Achene:

dry fruit that base of seed is attached to pericap // does not split at maturity

Samara:

dry fruit that is pericarp extends out to form a wing// does not split at maturity

Legumes:

dry fruit that splits along two sides or seams// splits at maturity

Capsules:

i. dry fruit that consist of at least 2 carpels and split in a variety of ways // splits at maturity

Nut:

i. dry fruit that larger with harder and thicker pericarp// does not split at maturity

Grain:

i. dry fruit that seed is tightly united with pericarp// does not split at maturity

Follicles:

i. dry fruit that splits along one side or seam// splits at maturity

siliques:

i. dry fruit that splits along two sides or seams, but seeds are borne on central partition when the two halves separate// splits at maturity

Schizocarp:

i. dry fruit that splits into two or more 1-seeded portions at maturity// does not split at maturity

What are the various parts of a fruit?

-Exocarp: skin -Endocarp: inner boundary around seeds -Mesocarp: fleshy tissue between exo and endocarps -Pericarp: part of the fruit from the wall of the ripened ovary

How do fleshy fruits differ from dry fruits?

-Fleshy fruits: mostly parenchyma // develop from a flower with a single pistil -Dry fruit: mostly sclerenchyma

What is the difference between a fruit and a vegetable?

-Fruit: an ovary and its accessory parts that have developed and matured // Usually contains seeds // All fruits develop from flower ovaries -Veggies: consist of roots, stems, and leaves - the non-fruit part of the plant

Distinguish between simple, aggregate, multiple, and accessory fruit. Give an example of each type of fruit.

-Simple: single flower with one ovary (peach, peas) -Aggregate: single flower with multiple ovaries (raspberries, strawberries) Compound: numerous ovaries -Accessory: contains other floral parts in addition to ovaries -Multiple: group of flowers with many ovaries which fuse to form a fruit (pineapples, figs)

What adaptations do seeds and fruits have for dispersal by water and animals?

-Wind dispersal: small and lightweight seeds -Animal dispersal: i. Seeds pass through digestive tracts ii. Fruits and seeds catch in fur or feathers iii. Oils attract ants -Water dispersal: i. Some fruits contain trapped air -Mechanical ejection of seeds