ch. 38 warm-up 1. compare and contrast: 2. what does each of the following develop into? a.zygote...
TRANSCRIPT
Ch. 38 Warm-UpCh. 38 Warm-Up1. Compare and contrast:
2. What does each of the following develop into?a. Zygoteb. Integumentc. Ovuled. Ovary
Pollination Fertilization Germination
Chapter 38Chapter 38Angiosperm Reproduction
What you need to know:What you need to know:The process of double
fertilization, a unique feature of angiosperms.
The relationship between seed and fruit.
The structure and function of all parts of the flower.
Angiosperms have 3 unique Angiosperms have 3 unique Features:eatures:
1.1. FFlowers2.2. FFruits3. double FFertilization
Alternation of GenerationsAlternation of Generations
1. Sporophyte (mature plant) produces spores
2. Spores develop into male (♂) gametophyte (pollen) and female (♀) gametophyte (embryo sac)
Flower StructureFlower StructureReproductive shoots of angiosperm
sporophyteFlower organs:
1. Sepal – leaflike, protect flower bud2. Petal – modified leaves, attract pollinators3. Stamen – ♂ reproductive organ
anther + filament
4. Carpel – ♀ reproductive organ stigma + style + ovary
Flower attached to stem at receptaclePollination by wind, insects, birds
Floral VariationsFloral VariationsComplete: has petals, sepals, stamen, carpelsIncomplete: lacks 1+ of the abovePerfect: has both stamen + carpelImperfect: has stamen or carpel, not both
(grass - no petals)Monoecious: plant species w/ both staminate
and carpellate flowers on the same individual (corn)
Dioecious: plant species w/ staminate flowers and carpellate flowers on different individual plants (date palm, arrowhead)
Bilateral symmetry(orchid)
SYMMETRY OVARY LOCATION FLORAL DISTRIBUTION
Lupine inflorescence
Superiorovary
Inferiorovary
Sunflowerinflorescence
Semi-inferiorovarySepal
Fused petals
Radial symmetry(daffodil)
REPRODUCTIVE VARIATIONS
Maize, a monoecious species Dioecious Sagittaria latifolia (commonarrowhead)
Male GametophyteFemale
Gametophyte= Pollen Sac = Embryo Sac
Produced in anther Produced in ovule (in ovary)
Has 2 haploid nuclei:1.Tube nucleus (forms pollen tube)2.Generative nucleus (divides to form 2 sperm cells)
Has 3 important haploid nuclei:1.Egg (fuses with sperm)2.2 polar nuclei (fuses with 2nd sperm to make 3n endosperm)
Pollination: transfer pollen from anther to stigma
Pollen tube grows down into ovary
Double FertilizationDouble Fertilization
Union of 2 sperm cells with different cells of embryo sac
1.One sperm + egg zygote (2n)2.One sperm + 2 polar bodies
endosperm (triploid 3n)◦ Endosperm = nutrition for embryo plant
3.Ovule develops into seed; ovary develops into fruit◦ Seed = embryo + endosperm
Self-incompatibility: prevent reject own pollen or closely related individual
Stigma Stigma
Pin flower
Antherwith
pollen
Thrum flower
““Pin” and “thrum” flower types reduce self-Pin” and “thrum” flower types reduce self-fertilizationfertilization
The development of a eudicot plant The development of a eudicot plant embryoembryo
FruitFruitProtects enclosed seed(s)Aids in dispersal by water, wind,
or animals
Simple Aggregate Multiple
Single ovary of one flower
Many ovaries of one flower
Many ovaries of
many flowers
Cherry Raspberry Pineapple
SeedsSeeds
Adaptations:1.Dormancy = “resting”
Low metabolic rate, not growing or developing
Increases chances of germination in most advantageous time & place
2.Dispersal: variety of methods3.Protection: well protected by fruit
GerminationGerminationImbibition: uptake of H2O
◦Seed expands and seed coat ruptures
◦Trigger metabolic changes to begin growth
◦Enzymes digest storage materials of endosperm (cotyledons)
◦Nutrients transferred to growth regions of embryo
GerminationGermination
1. Radicle Root2. Shoot tip emerges above ground
Stimulated by light
3. Foliage leaves expand & turn green photosynthesis
Very hazardous for plants due to vulnerability
◦ Predators, parasites, wind
Sexual AsexualBoth ways to reproduce
Flower seedsRunners, bulb, root, graft,
vegetative (grass), fragmentation
Genetic diversity Clone
More complex & hazardous for plant
Simpler & safer for plant
• Monoculture - cultivate w/ 1 plant
• Reduces competition• Benefits farmers
Plant ReproductionPlant Reproduction
Asexual reproduction in aspen Asexual reproduction in aspen treestrees
Just a few parenchyma cells from a carrot gave rise to this callus, a mass of undifferentiated cells.
The callus differentiates into an entire plant, with leaves, stems, and roots.
Test-tube cloning of carrotsTest-tube cloning of carrots