22 1 Plant Life Cycles KEY CONCEPT All
- Slides: 14
22. 1 Plant Life Cycles KEY CONCEPT All plants alternate between two phases in their life cycles.
22. 1 Plant Life Cycles Plant life cycles alternate between producing spores and gametes. • A two-phase life cycle is called alternation of generations. – haploid phase – diploid phase – alternates between the two SPOROPHYTE PHASE fertilization meiosis GAMETOPHYTE PHASE
22. 1 Plant Life Cycles • The sporophyte is the dominant phase for seed plants.
22. 1 Plant Life Cycles KEY CONCEPT Reproduction of flowering plants takes place within flowers.
22. 1 Plant Life Cycles Flowers contain reproductive organs protected by specialized leaves. • Sepals and petals are modified leaves. – Sepals are outermost layer that protects developing flower sepal
22. 1 Plant Life Cycles – Petals can help to attract animal pollinators petal
22. 1 Plant Life Cycles • A stamen is the male structure of the flower. stamen filament anther – anther produces pollen grains – filament supports the anther
22. 1 Plant Life Cycles • The innermost layer of a flower is the female carpel. stigma carpel style ovary – stigma is sticky tip – style is tube leading from stigma to ovary – ovary produces female gametophyte
22. 1 Plant Life Cycles Flowering plants can be pollinated by wind or animals. • Flowering plants pollinated when pollen grains land on stigma. • Wind pollinated flowers have small flowers and large amounts of pollen.
22. 1 Plant Life Cycles • Animal pollinated flowers have larger flowers and less pollen. – many flowering plants pollinated by animal pollinators pollen grains – pollination occurs as animal feeds from flower to flower – animal pollination more efficient than wind pollination
22. 1 Plant Life Cycles • Pollination occurs when a pollen grain lands on a stigma. pollen tube sperm stigma
22. 1 Plant Life Cycles • Flowering plants go through the process of double fertilization. female gametophyte egg sperm polar nuclei ovule
22. 1 Plant Life Cycles • Flowering plants go through the process of double endosperm fertilization. – one sperm fertilizes the egg seed coat – other sperm unites with polar nuclei, forming endosperm – endosperm provides food supply for embryo
22. 1 Plant Life Cycles • Each ovule becomes a seed. • The surrounding ovary grows into a fruit.
Plant life cycles and alternation of generations
Lesson 2 cycles of matter answer key
Practice geochemical cycles answer key
Alliteration for cycle
Bill nye life cycles
Life cycle of a bird
Life cycle of a star assessment
Life cycles of stars
Style fashion and fad life cycles
Club fungi life cycle
Chapter 13: meiosis and sexual life cycles
Precipitation in the water cycle
Chapter 13 meiosis and sexual life cycles
A key concept of quality control is that all work products
Name all the lines
