Botany Lec Flashcards
2 purpose of reproduction
1- to perpetuate identical child plants by asexual reproduction
2- to perpetuate varied child plants by sexual reproduction
Cell division and differentiation
Cytokinin
Growth stop
Indolacetic acid IAA AUXIN
Germination, elongation
Gibberelic acid
Seed dormancy, drought resistance
Abscissic acid
Ripening, stress response, leaf abcission
Ethylene
The plant has 2 phases/generations/alterants
Gametophyte (n)
Sporophyte (2n)
Diphasic
The 2 alterants are different in appearance
Heteromorphic
Haploid cell egg and haploid sperm cell unite to form diploid zygote
Fertilization or syngamy
In the anther undergo meiotic division
Microspore mother cells or
microsporocytes
A microspore is produced is nursed by
tapetum
A microspore mitotic division and produces
2 sperm nuclei and a pollen tube nucleus
The pollen nucleus will elongate when the pollen reach the stigma
Allowing the sperm cells to enter the ovule
Microgametophyte
Intricate cell wall
Exine outer layer having sporopollenin
A substance that prevent the pollen from drying up and inner intine layer
Sporopollenin
Megagametophytes
Venue for the whole fertilization process
Syngamy consists of 2 parts
1 plasmogamy or protoplasm fusion
2 karyogamy or nuclei fusion
Fertilization
1- the pollen reaches out its egg cells through the pollen tube
Fertilization
2- First fertilization
The first sperm reaches through the microphyle through the synergids and final to the egg. They fertilize and give rise to the zygote, later the embryo
Fertilization
3- second fertilization
The second sperm cell reaches the polar nuclei at the center, but no karyogamy occurs in resulting cell is tripod(2n). This will become the primary endosperm later the permanent endosperm
Fertilization
4- after 2 fertilization, the ovule will slowly develop its embryo and the three shape defined stages will come:
A- globular stage
B- heart stage
C- torpedo stage
Germination
drying
Up to 95% of the seed body
imbibition
Absorption of water by hydrophilic parts of the seed
Germination
4- growth of the radicle
Become the primary root
Egg cell (fertilized)
Zygote (to embryo)
Polar cell (fertilized)
Endosperm
Entegument to
Testa /tegmen
Funiculus
Hilum
Micropyle
Remains microplye
Nucellus and suspensor
Will be crushed
Antipodals and synergids
Will degenerate
Anti helmintic seeds
Saga saga, ipil ipil
Tanecide
Bunga
Vitamins
Palay beans
Anti diabetic
Duhat seeds