Gymnosperms and Angiosperms

1. Gymnosperms and Angiosperms Biology 112 Presentation 4

2. Gymnosperms • Include pines, spruce, juniper, fir and other cone bearing plants. • Thin, needle-like leaves are a special adaptation to hot-dry summers and cold winters, with moderate rainfall. • Needles retain moisture because of their thick waxy cuticle. • Their roots extend over a wide surface area, as opposed to penetrating deep into the soil.

4. Angiosperms • Comprise more than all the other plant division combined (over 250 000 known.) • Many angiosperms and insects have become completely inter-dependant. • This process of joint evolution of two or more species is called coevolution.

7. Common Characteristics of Flowers • Stamen is the male part of the flower. It consists of: • A thin stalk called a filament • An anther where pollen is formed • The carpel, or pistil is the female part of the flower. It consists of: • The stigma – sticky part which pollen lands and grows • The style – slender stalk pollen grains travel to ovary • The ovary – contains ovule

8. More Common Characteristics of Flowers • Sepals – small green leaf-like structures that surround the carpel and stamen • Petals – colorful part that attracts pollinators • Nectary – small swelling at base of each petal

9. Complete, or Incomplete - Flowers • Complete flowers contain carpels, stamens, petals, and sepals. • I.e. lilies, tomatoes, etc. • Incomplete flowers are missing at least one of these structures. • In most species the petals die off after fertilization.

10. Reproduction • Refer to your handout for life cycle. • Do worksheet.

11. Monocots • Monocotyledons is an angiosperm whose seeds have only one cotyledon or seed leaf. • Vascular bundles distributed throughout stem • Veins parallel • Flowers in 3s or multiples of 3

12. Dicots • Dicotyledon is an angiosperm whose seeds have two cotyledons or seeds leaves. • Vascular bundles arranged in ring • Veins netlike • Flowers in multiples of 4s or 5s