Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Plant reproduction

No description

Tia Caldwell

on 23 October 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Plant reproduction

Chapter 38: Plant Reproduction
and Biotechnology

The Male Gametophyte: Pollen Grain
Development of Female Gametophyte: Embryo Sac
Adaptations to prevent self-fertilization
Embryo Development
Structure of the Mature Seed
Adaptations of Seed Germination
From Seed to Seedling
- Life cycles of angiosperms comprise of by an alternation of generations
haploid (n)
diploid (2n)

- Sporophyte (diploid) is dominant - the part of the plant that we see
- Angiosperm gametophytes (haploid) consist of only a few cells
The basics of Sexual Reproduction
Sexual Reproduction
of Angiosperms

Alternation of generations
Haploid= divides by meiosis & ends up with 1/2 the DNA

Diploid= two haploid cells joined together (double DNA)

All plants that go through meiosis spend some time as haploid & diploid cells

**Alternates being a haploid & being a diploid plant**
Produces spores by meiosis
Spores divide by mitosis
creates male/female gametophytes -> Gametes
Fertilization = diploid zygotes
Divides by mitosis= sporophytes
Pollinating agents
animals or insects
brings male and female gametophytes together
Dioecious plants
Physical structure or stamens and carpels mature at diff times
Self-incompatibility with S-genes
pollen grain grows a pollen tube down the style
Male gametes-
2 sperm form
The pollen tube enters the embryo sac and deposits the sperm
Double Fertilization
one sperm fertilizes...
the egg
the two polar nuclei

Flowering plant--> plant seeds
Color & scent attracts pollinators
Fertilization-> ovary becomes fruit & ovule becomes seed
Aids in dispersal by attracting animals
triploid nucleus
Flowers are reproductive shoots

1. Sepals are green, leafy, & enclose/protect the floral bud

2. Petals are brightly colored & attract pollinators

3. Stamens are the male reproductive organs.
Has a stalk called the filament & a terminal structure called the anther; within this are pollen sacs

4. Carpels are the female reproductive organs.
Has an ovary at its base & a neck called the style with a sticky structure at its top called the stigma for pollen to land
Endosperm development
Tripliod nucleus of ovule's central cell divides forming the endosperm
liquid endosperm
divides to become multicellular
cells develop cell walls
endosperm solidifies
•Complete flowers- has all 4 floral organs

•Incomplete flowers- lacks one or more organs

•Bisexual flower- In the presence or absence of reproductive organs, a plant will be equipped with both stamens and carpels

•Unisexual flower- is missing either stamens or carpels. Are also called staminate and carpellate. If staminate/carpellate are located on the same plant, then it is monoecious

•Monoecious - staminate & carpellate flowers are on one plant (ex: corn)

•Dioecious- staminate & carpellate flowers are on separate plants (ex: asparagus)
1. Pollen sacs contain diploid cells called microsporocytes which go under meiosis in order to form 4 haploid microspores

2. The splitting of the diploid cells results in haploid male gametophytes
3. These microspores divide by mitosis and produce two cells; a generative cell and a tube cell

Generative cells produce sperm
Tube cells enclose the generative cell and produce a pollen tube to assist in sperm delivery
The pollen grain lands on the stigma of a carpel and the pollen tube deposits the sperm
1. Through mitosis, the zygote splits
- Ovules contain a sporangium in the ovaries.

- Each cell in the sporangium is known as a megasporocyte

- The megasporocyte goes through meiosis and produces four haploid megaspores

- Membranes then divide into a multicellular gametophyte; an embryo sac
will form most of the embryo
forms suspensor - anchors embryo to parent
from terminal cell
- Embryo sacs have three cells: the egg cell (the female gamete), and two cells called synergids

- The ovule, soon to become a seed, consists of the embryo sac and sporophytic tissue of the ovary

- Synergids are on either side of the egg and guide the pollen tube, the carrier of the sperm, to the egg
from basal cell
Cotyledons (seed leaves)
form on the proembryo
(embryonic axis)
(embryonic root)
end of hypocotyl
part of hypocotyl
above the cotyledons
shoot tip
only one
sheath that covers
young root
covers young shoot
The ovary develops into a fruit
wall of ovary develops into pericarp
other parts of flower wither and die
ripens as seed matures
in fleshy fruit, enzymes digest cell wall and convert molecules into sugar
dormancy - low metabolic rate, no growth
certain environmental factors break seed dormancy
time in dormancy varies
inbibition- uptake of water by seeds
seed ruptures coat + resumes growth w/ stored energy
Asexual Reproduction
radical/ embryonic root grows from seed
shoot tip breaks surface
Several Types:
-Fragmentation (most common)
form of asexual reproduction where a new organism grows from a fragment of the parent
formation of a new sporophyte without fertilization

diploid cell in ovule gives rise to the embryo and the ovules mature into seeds - dispersed by wind
The seedling
expensive for the plant
offspring derived from a single parent without genetic recombination
Vegetative Reproduction of Plants is Common in Agriculture
Callus - at the end of plant shoots are calluses - roots develop from callus through asexual reproduction
plant that provides the root system = stock
twig grafted onto the stalk = scion
Asexual reproduction is an extension of the capacity of plants for indeterminate growth
meristematic tissues with dividing undifferentiated cells can sustain or renew growth indefinitely
parenchyma cells throughout the plant can divide and differentiate into various types of specialized cells.
detached fragments of some plants can develop into whole offspring.
Plant Biotechnology
biotechnology refers to the use of genetically modified organisms in agriculture and industry.
interspecific hybridization of plants is common in nature - used by breeders, farmers to introduce new genes into crops
genetically modified plants have the potential of increasing the quality and quantity of food
Full transcript