LESSON 9 SEXUAL REPRODUCTION IN FLOWERING PLANTS KEY CONCEPTS Open your yellow book to page 107

THE FLOWER IS THE SEXUAL REPRODUCTIVE ORGAN OF A FLOWERING PLANT. Concept #1 THE FLOWER IS THE SEXUAL REPRODUCTIVE ORGAN OF A FLOWERING PLANT.

Concept #2 PERFECT flowers contain both MALE and FEMALE reproductive structures. IMPERFECT flowers contain EITHER the male or the female reproductive structure.

Concept #3 POLLINATIONis the transfer of POLLENfrom ANTHERto STIGMA. POLLEN GRAINS from different kinds of plants are very different in SIZE and SHAPE.

Some plants SELF-POLLINATE; others require CROSS- POLLINATION. Concept #4 Some plants SELF-POLLINATE; others require CROSS- POLLINATION.

Concept #5 Pollen can be transported by WIND, WATER, GRAVITY, INSECTS, and HUMANS, among other things.

Concept #6 FERTILIZATION occurs when a SPERM NUCLEUS from a POLLEN GRAIN unites with the EGG NUCLEUS of an OVULE in an OVARY. A SEED begins to form when fertilization occurs. The OVARY becomes the FRUIT.

LESSON 9 SEXUAL REPRODUCTION IN FLOWERING PLANTS Types of Pollination

1. Self - Pollination Process by which a plant pollinates itself (1 plant involved) Genetically identical offspring Occurs in different flowers on the same plant ASEXUAL REPRODUCTION

Self-pollination advantages Makes sure plant does not go into extinction If parent can survive in habitat, so can offspring

Self-pollination disadvantages No variation, so no evolution Disease may spread easier among identical offspring

2. Cross Pollination One plant pollinates another plant (2 plants involved) Genetically different offspring Different plant, different flowers (must be from same species) SEXUAL REPRODUCTION

Cross-pollination advantages Evolution because offspring not identical to parent or other offspring Disease will not affect all offspring at once because not genetically identical

Cross-pollination disadvantages Pollen might not reach stigma (must be compatible to work) Two parent flowers, two different plants, same species (much more specific)