Ferns that are pretty

Chapter 30 Reading Quiz 1.An embryo packaged with a food supply and a protective coat is a … 2.What is the transfer of pollen to ovules called? 3.What is the only living species of Ginkgophyta? 4.How many species of Coniferophyta are there? 5.What are the two main classes of Anthophyta?

1. Describe the adaptations of seed plants that have contributed to their success on land. 1.Reduction of the gametophyte 2.Origin of the seed  zygote with food supply and protective coat 3.Evolution of pollen – plants no longer tied to water for fertilization

2. List the four divisions of gymnosperms. 1.Cycadophyta  cycads 2.Ginkgophyta  ginkgoes 3.Gnetophyta  gnetophytes 4.Coniferophyta  conifers

3. Describe the structures of ovulate and pollen cones of a pine and distinguish between the two. Pollen cones have microsporangia; undergo meiosis to produce haploid microspores which develop into pollen Ovulate cones have megasporangia; undergo meiosis to produce large megaspores that develop into the female gametophyte  most trees bear both pollen & ovulate cones (heterosporous) which develop on different branches

4. Describe the life history of a pine and indicate which structures are part of the gametophyte generation and which are part of the sporophyte generation. It takes 3 years to complete the pine life cycle 1.Pollen grain burrows into ovule 2.Cell undergoes meiosis to make 4 haploid megaspores; one survives and grows into the multicellular gametophyte 3.2 or 3 archegonia, each with an egg, develop inside 4.More than a year after pollination, eggs are ready to be fertilized – pollen tube grows through 5.One zygote develops into pine embryo (sporophyte) 6.The pine “seed” then blows away and germinates elsewhere

5. Point out the major life cycle differences in ferns and pines. Pines are much more complex Pine reproduction takes about 3 years Pines don’t need water for fertilization

6. Distinguish between pollination and fertilization. Pollination  pollen into stigma of carpel - is a prerequisite to fertilization Fertilization  the union of haploid gametes to form a diploid zygote

7. Describe a pine seed and indicate which structures are old sporophyte, gametophyte, and new sporophyte. Pine seed: 1.Embryo  2n  new sporophyte 2.Food source  n  gametophyte 3.Surrounding seed coat  2n  old sporophyte

8. Describe how the needle-shaped leaves of pines and firs are adapted to dry conditions. There is a thick cuticle that covers each leaf The leaf’s stomata are found in pits, reducing water loss Little surface area for evaporation

9. List and give examples of the two classes of Anthophyta. 1.Monocotyledons (monocots) - parallel leaf veins - grasses 2.Dicotyledons (dicots) - netted leaf veins - lettuce, maples

10. Compare the life cycles of mosses, ferns, conifers, and flowering plants in terms of: dominant life cycle stage (gametophyte/sporophyte), whether they are homosporous or heterosporous, mechanism of gamete transfer Mosses  gametophyte, heterosporous, sperm swim to egg Ferns  sporophyte, homosporous, water is necessary Conifers  sporophyte, heterosporous, pollen fertilizes ovary Flowering plants  sporophyte, heterosporous, pollen fertilizes ovary

11. Describe some refinements in vascular tissue that occurred during angiosperm evolution. Conifers have tracheids which conduct water (the early type of xylem cell) Angiosperms also have xylem, but use vessel elements, which is a more efficient cell than the tracheids

12. Explain how evolution of the flower enhanced the reproductive efficiency of angiosperms. The ovary dropped below the petals and sepals where the ovules are better protected

13. Identify the following floral structures and describe a function for each: sepals, anther, petals, stigma, stamens, style, carpels, ovary, filament Sepals  sterile leaves, enclose bud Petals  sterile, aid in attracting pollinators Stamen  produces pollen Carpel  evolved from seed-bearing leaf rolled into tube Stigma  part of carpel that is sticky and receives the pollen Ovary  protects ovules which develop into seeds Filament  stalk of stamen Anther  terminal sac of stamen where pollen is produced Style  leads to ovary

14. Describe four commonly recognized evolutionary trends in floral structure found in various angiosperm lineages. 1.The number of floral parts have become reduced 2.Floral parts have become fused together 3.Symmetry has changed from radial to bilateral 4.The ovary has dropped below the petals and sepals where the ovules are better protected

15. Define fruit and explain how fruits are modified in ways that help disperse seeds. Fruit  a ripened ovary that protects dormant seeds and aids in their dispersal; some fruits (like apples) incorporate other floral parts along with the ovary Dispersal techniques  - wind dispersal (dandelions) - burr-like fruit that cling to animal fur - edible fruit whose seeds go through the digestive tract of the animal and end up elsewhere

16. Diagram the generalized life cycle of an angiosperm, identify which structures are haploid, and explain how it differs from the life cycle of a pine. 1.Pollen lands on a sticky stigma 2.Pollen grain germinates on stigma by growing a pollen tube down the style of the carpel 3.Reaches ovary and pollen tube grows through its micropyle and discharges 2 sperm into embryo sac 4.Double fertilization occurs when one sperm unites with the egg to form the diploid zygote; the other fuses with 2 nuclei in the embryo sac’s central cell to form a triploid endosperm 5.After double fertilization, the ovule matures into a seed, and is ready for dispersal

17. Explain how an angiosperm seed differs from that of a pine. Pine seeds  have old and new sporophyte and gametophyte incorporated into the seed itself Angiosperm seeds  have fruits that help disperse the seeds and the fruit is usually the endosperm (3n)

18. Explain why paleobotantists have difficulty piecing together the origin of angiosperms and describe some current theories on how flowering plants may have evolved. Angios have a relatively sudden appearance in the fossil record – there are no clear links to ancestors Theories: 1.Angios originated where fossilization was unlikely 2.Angios evolved and radiated relatively abruptly (punctuated equilibrium) - perhaps angios evolved from seed ferns, an extinct group of unspecialized gymnosperms

19. Explain how animals may have influenced the evolution of terrestrial plants, and vice versa. It is a consequence of interdependence Coevolution  reciprocal evolutionary responses among two or more interacting species; an adaptive change in one species is in response to evolutionary change in the other species