9.3:9.3:

9.3.1 Draw and label the structure of a 9.3.1 Draw and label the structure of a dicotyledonous animal-pollinated flower. dicotyledonous animal-pollinated flower.

Limit the diagram to Limit the diagram to

• sepalsepal• petalpetal• StamenStamen

– antheranther– filamentfilament

• PistilPistil– stigmastigma– style style – ovaryovary

9.3.2 Distinguish between 9.3.2 Distinguish between pollination, fertilization, seed dispersalpollination, fertilization, seed dispersal

• Pollination: – 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

9.3.3 Draw and label the external and 9.3.3 Draw and label the external and internal structure of a internal structure of a NAMEDNAMED

dicotyledonous seed.dicotyledonous seed.• Pea seed (Pea seed (Pisum sativumPisum sativum), p 158), p 158

9.3.4 Explain the conditions needed for 9.3.4 Explain the conditions needed for the germination of a typical seed.the germination of a typical seed.

• Usually dormant for a whileUsually dormant for a while– Germination = resumption of growth/develpmtGermination = resumption of growth/develpmt– Depends on species (some need fire, digestive Depends on species (some need fire, digestive

enzymes, etc)enzymes, etc)• WaterWater

– Taken in, swells up, testa cracks, hydrolytic Taken in, swells up, testa cracks, hydrolytic enzymes activated, break down starch to maltoseenzymes activated, break down starch to maltose

• OxygenOxygen– Final e- acceptor in aerobic cell resp, releases Final e- acceptor in aerobic cell resp, releases

energy needed for germination to occurenergy needed for germination to occur• Suitable temperatureSuitable temperature

– (varies among species)(varies among species)– Low then high; high then low...so seed Low then high; high then low...so seed

germinates at proper season; enzyme actiongerminates at proper season; enzyme action

9.3.5 Outline the metabolic 9.3.5 Outline the metabolic processes during germination of a processes during germination of a starchy seed.starchy seed.

1.1. Absorption of water for metabolism to start Absorption of water for metabolism to start (amylase, etc)(amylase, etc)

2.2. Amylase catalyzes break down of starch (stored) Amylase catalyzes break down of starch (stored) into maltose, moves to embryo, used for cell resp into maltose, moves to embryo, used for cell resp & to make cellulose for new cell walls& to make cellulose for new cell walls

3.3. Stored proteins & lipids hydrolyzedStored proteins & lipids hydrolyzed4.4. Those AAs used to make new proteins, lipids for Those AAs used to make new proteins, lipids for

energy and cell membranesenergy and cell membranes5.5. Germination uses food stored in cotyledons until Germination uses food stored in cotyledons until

grows enough to photosynthesize (leaves)grows enough to photosynthesize (leaves)

9.3.6 Explain how flowering is controlled in long-day 9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of and short-day plants, including the role of

phytochromephytochrome• Some plants need min # hrs Some plants need min # hrs darknessdarkness before before

floweringflowering– Spring/fall flowers (days shorter) “Spring/fall flowers (days shorter) “short-dayshort-day

plants” (ex-strawberry, coffee)plants” (ex-strawberry, coffee)

• Some—max # hrs Some—max # hrs darknessdarkness – Summer flowers, “Summer flowers, “long-daylong-day plants” (carnations, plants” (carnations,

clover)clover)

• Some – neutral Some – neutral • Photoperiodicity (many use phytochromes to Photoperiodicity (many use phytochromes to

regulate it)regulate it)

9.3.6 Explain how flowering is controlled in long-day 9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of and short-day plants, including the role of

phytochromephytochrome• Phytochrome = photoreceptor (ptn, absorbs Phytochrome = photoreceptor (ptn, absorbs

light)light)• 2 states: Pr, Pfr2 states: Pr, Pfr• conversion of Pr (red absorbing) to Pfr (far-conversion of Pr (red absorbing) to Pfr (far-

red absorbing) in red or white light, red absorbing) in red or white light, • gradual reversion of Pfr to Pr in darkness,gradual reversion of Pfr to Pr in darkness,

• Pfr as a promoter of flowering in long-day Pfr as a promoter of flowering in long-day plants plants

• Pfr as an iPfr as an inhibitor of flowering in short-day nhibitor of flowering in short-day plantsplants

9.3.6 Explain how flowering is controlled in long-day 9.3.6 Explain how flowering is controlled in long-day and short-day plants, including the role of and short-day plants, including the role of

phytochromephytochrome

Even a flash of light @ night can mess up the slow conversion of Pfr back to Pr