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Chapter 10: Flowers and Reproduction - Coggle Diagram
Chapter 10: Flowers and Reproduction
Concept
two functions of reproduction
producing offpring that have identical copies of the parental genes
generating individual that are genetically different from the parents
Asexual reproduction
Fragmentation
spliting of cells into two parts and makes new bodies
each fragment develops into a mature clone genetically and morphologically identical to its parent.
Sexual Reproduction
The plant life cycle
is complex
trees, shrubs and herbs have one phase of plant life cycle called sporophyte generation
Sporophytes are always diploid.
meiosis results in haploid spores
two types of mammalian gametes
microgametes: small sperm cells that swims
megagametes: large egg cells that do not swim.
two type of gametophytes
microgametophyte developed from microspore
megagametophytes: developed from megaspores
Alternation of generation
lifecycle with two generation: sporophyte and gametophyte
heteromorphic generation
life cycle with one sporophyte and two gametophyte
Flower structure
Sepals
lowermost and outermost of the four floral appendages.
thickest, toughest and waxiest of the flower parts.
All sepals together are refers as calyx
Petals
above the sepals on the receptacle
petals together are known as corolla
sepals and petal together constitute the flower's perianth
Stamens
Above the petals, collectively known as androecium
two parts
filaments: stalk
anther: where pollen is actually produced
Carpels
located at the highest level on the receptacle
consists gynoecium
three parts
Stigma: that catches pollen grain
Style: that elevates the stigma to a useful position
Ovary: where megaspores are produced
Gametophytes
Micro gametophyte
Microspore migrate to the site of pollen grains
microspore dive and produce vegetative cells and generative cells
vegetative and generative cells divide and produce sperm cell.
megagametophyte
embryo sac: technical term for a nucleate megagametophyte
Seven cells from megagametophyte: one central cell, three antipodal cells, an egg apparatus and two synergids
Fertilization
Plasmogamy: is a stage in the sexual reproduction of fungi, in which the protoplasm of two parent cells fuses together without the fusion of nuclei
Double fertilization: involves two sperm cells; one fertilizes the egg cell to form the zygote, while the other fuses with the two polar nuclei that form the endosperm
Endosperm: nourishes the development of zygotes
Embryo and seed development
suspensor: pushes embryo deep into the endosperm
cell at the end of suspensor divide and develop into embryo
Embryo grows into cotyledons and eudicots
Fruit development
Ovary mature into fruits
pericarp: the entire fruit wall whether composed of one, two or three layers
Flower structure and cross pollination
Monoecious and dioecious species
Imperfect flower
that lacks either or both essential organs
perfect flower
have both essential organs
sepals and petals do not produce spores and are considered as nonessential organs
Dioecy: produce either staminate flower or carpellate flower but not both
Monoecy: condition of having staminate flowers located on the same plants as carpellate flowers
Animal pollinated flower
coevolution
flower become adapted for visitation by a particular insect and the insect for efficient exploitation of the flower.
Actinomorphic flower:
When the different members of each whorl are alike,
Zygomorphic
monosymmetric, bilateral, and irregular flowers
Stigma and pollen Incompatibility
Compatibility barriers
chemical reaction between pollen and carpels that prevent pollen growth.
self-pollination is inhibited by compatibility barriers
stamens and style maturation time
Self fertilization in flower that have both stamens and carpels is prevented if anther and stigmas mature at different times
Wind-pollinated flower
distinct set of modification is adaptive
Sepals are also reduced or absent
ovaries need no special protection
Cross-pollination
pollination of a carpel by pollen from a different individuals
Ovary position
Inferior ovary
can result is receptacle tissue grows upwards around the ovary
superior ovary
ovary is above the other flowers plants
half-inferior
partially buried ovaries
Inflorescence and pollination:
Two basic arrangement
determinate inflorescences
Has only a limited potential for growth because the inflorescence apex is converted to a flower.
indeterminate inflorescences
the lowest or outermost open flower opens first
new flowers are still being initiated at the apex
True fruits and Accessory fruits
True fruits
fruits containing only ovarian tissue
Accessory fruits
non-ovarian tissue is present
Fusion of carpel affect the nature of the fruits
Simple fruits
fruit develop from a singe ovary or the fused ovarian of one flower
Aggregate fruits
separate carpel of one gynoecium fuse during development
Multiple fruits
during development all of the individual fruits of an inflorescence fuse into one fruit.
Classification of fruits
Dry fruits
not typically eaten by natural seed distributing animals
Flesh fruits
eaten during the natural seed distribution process
Dehiscent fruits
break open and release the seeds
indehiscent fruits
do not release the seeds
