1. 9.3:

2. 9.3.1 Draw and label the structure of a dicotyledonous animal-pollinated flower. Limit the diagram to
sepal
petal
Stamen
anther
filament
Pistil
stigma
style
ovary

6. 9.3.2 Distinguish between pollination, fertilization, seed dispersal
transfer of pollen grains from anther to carpel
Wind, insects, water
Doesn’t always lead to... (cross-species)
Fertilization:
fusion of male and female gametes to form new organism
Seed dispersal:
moving seeds away from parent plant (reduces competition) fert’d ovules form seeds
Fruit, wind, water, animals

8. 9.3.3 Draw and label the external and internal structure of a NAMED dicotyledonous seed.
Pea seed (Pisum sativum), p 158

10. 9.3.4 Explain the conditions needed for the germination of a typical seed.
Usually dormant for a while
Germination = resumption of growth/develpmt
Depends on species (some need fire, digestive enzymes, etc)
Water
Taken in, swells up, testa cracks, hydrolytic enzymes activated, break down starch to maltose
Oxygen
Final e- acceptor in aerobic cell resp, releases energy needed for germination to occur
Suitable temperature
(varies among species)
Low then high; high then low...so seed germinates at proper season; enzyme action

12. 9.3.5 Outline the metabolic processes during germination of a starchy seed.
Absorption of water for metabolism to start (amylase, etc)
Amylase catalyzes break down of starch (stored) into maltose, moves to embryo, used for cell resp & to make cellulose for new cell walls
Stored proteins & lipids hydrolyzed
Those AAs used to make new proteins, lipids for energy and cell membranes
Germination uses food stored in cotyledons until grows enough to photosynthesize (leaves)

14. Some plants need min # hrs darkness before flowering
9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome
Some plants need min # hrs darkness before flowering
Spring/fall flowers (days shorter) “short-day plants” (ex-strawberry, coffee)
Some—max # hrs darkness
Summer flowers, “long-day plants” (carnations, clover)
Some – neutral
Photoperiodicity (many use phytochromes to regulate it)

15. 9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome
Phytochrome = photoreceptor (ptn, absorbs light)
2 states: Pr, Pfr
conversion of Pr (red absorbing) to Pfr (far-red absorbing) in red or white light,
gradual reversion of Pfr to Pr in darkness,
Pfr as a promoter of flowering in long-day plants
Pfr as an inhibitor of flowering in short-day plants

16. 9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome
Even a flash of night can mess up the slow conversion of Pfr back to Pr