Chapter #2 - 3 Sexual Reproduction in Plants Seed - reproductive package that contains an embryo, food supply,

seed coat – product of sexual reproductionAngiosperms – flowering plants – seeds form inside flowers, when

mature the seeds are enclosed in case (pod or shell)Gymnosperms – do not produce flowers - produce seeds inside cones - a coat protects from dehydration - not enclosed inside a case

Pollination and Fertilization in Angiosperms- Some produce large showy flowers while others produce tiny flowers that are often not seenPistil - female reproductive organ Stamen - male reproductive organPollination - pollen grains from anthers on stamen reach stigma of

pistil - pollen grain must grow a pollen tube to reach ovule for fertilization to occur

Self-pollination - male and female gametes come from same plantCross-pollination - gametes from 2 different parent plants – pollen

from one anther is transferred to stigma on different plantAgents of cross pollination = wind, insects, animals

Self-pollination - male and female gametes come from same plantCross-pollination - gametes from 2 different parent plants – pollen

from one anther is transferred to stigma on different plantAgents of cross pollination = wind, insects, animals

Seed Development in Angiosperms- While pollen tube is growing, cells inside ovule begin preparation- Sperm fertilizes egg - zygote- Other cells in ovule have developed into cotyledon which contains

stored foodZygote – mitotic division – form many celled embryo with miniature

leaf, root, stemFruit - Developing seed surrounded by walls of ovary which matures

to form fruits (pod or case around seed)Seed Dispersal in Angiosperms

Fruit often aids in dispersal – seeds not digested - droppingsLaunch - some able to project their own seedsHitch - cling to furry animals - fall off when rubbed or

removed Wind - fluffy sails that are easily swept away by windWater - run off of rain carries seeds that fall on ground

Dispersal – decreases competition with parent plant

Fruit often aids in dispersal – seeds not digested - droppingsLaunch - some able to project their own seedsHitch - cling to furry animals - fall off when rubbed or

removed Wind - fluffy sails that are easily swept away by windWater - run off of rain carries seeds that fall on ground

Dispersal – decreases competition with parent plantGermination and growth in Angiosperms

- process in which a seed begins to grow- some seeds remain dormant or inactive for years and only

germinate when they encounter favourable conditions

Sexual Reproduction in GymnospermsSexual Reproduction in Gymnosperms- Gymnosperms do not bear flowers - have cones and often - Gymnosperms do not bear flowers - have cones and often

called coniferscalled conifers- male cones (pollen) and female (ovule) - in some species- male cones (pollen) and female (ovule) - in some species

male and female cones are produced on separate trees male and female cones are produced on separate trees - most have both types of cones on same tree- most have both types of cones on same tree- Seed of gymnosperm contains an embryo, food - Seed of gymnosperm contains an embryo, food

supply, coat that supply, coat that protects from drying outprotects from drying out- Seed not contained in a fruit- Seed not contained in a fruit

Sexual Reproduction in GymnospermsSexual Reproduction in Gymnosperms- Gymnosperms do not bear flowers - have cones and often - Gymnosperms do not bear flowers - have cones and often

called coniferscalled conifers- male cones (pollen) and female (ovule) - in some species- male cones (pollen) and female (ovule) - in some species

male and female cones are produced on separate trees male and female cones are produced on separate trees - most have both types of cones on same tree- most have both types of cones on same tree- Seed of gymnosperm contains an embryo, food - Seed of gymnosperm contains an embryo, food

supply, coat that supply, coat that protects from drying outprotects from drying out- Seed not contained in a fruit- Seed not contained in a fruit

Sexual Reproduction in Plants without SeedsSexual Reproduction in Plants without Seeds- - Mosses, ferns, liverworts reproduce without seeds – use Mosses, ferns, liverworts reproduce without seeds – use

sporesspores - Spores are haploid but a spore can develop into a new plant - Spores are haploid but a spore can develop into a new plant body without fertilizationbody without fertilization

SporophyteSporophyte – fine stalks – haploid – produce spores – fine stalks – haploid – produce sporesGametophyteGametophyte – under right conditions spore develops into a – under right conditions spore develops into a gametophyte that produces gametesgametophyte that produces gametesSporesSpores – very light - carried great distances - survive unfavourable – very light - carried great distances - survive unfavourable

temperatures and droughts (stay dormant for long periods of temperatures and droughts (stay dormant for long periods of time time and still produce healthy plants when conditions are better)and still produce healthy plants when conditions are better)