1 BOWEN UNIVERSITY, IWO PURE AND APPLIED BIOLOGY PROGRAMME COURSE CODE: BLY 102 COURSE TITLE: GENERAL BIOLOGY II SEMESTER: SECOND TITLE: GENERAL CHARACTERISTICS AND STRUCTURE OF PLANT DIVISION 1. Division: Thallophyta These are plants that do not have well-differentiated body form (i.e. thalloid). They are found both in terrestrial and aquatic habitats, but are predominantly aquatic; freshwater or marine. It has only one subdivision Algae. Examples are Spirogyra, Ulothrix, Cladophora and Chara. Various types of fungi like yeasts and moulds which do not have chlorophyll are also included in this group. Sub-division: Algae • They are autotrophs • The body is simple and not well differentiated (i.e. they possess thalloid body form) • The form and size of algae are variable. Chlamydomonas is microscopic unicellular algae. Volvox is in colonial form. Ulothrix and Spirogyra are filamentous. • They are further classified as green algae, red algae and brown algae. Red and brown algae are due to the presence of accessory photosynthetic pigments.
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PURE AND APPLIED BIOLOGY PROGRAMME · 2021. 6. 22. · Angiospermae. Sub-division: Gymnospermae (Greek; gymno – naked, spermae – seed) • The plants of this group bear naked
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BOWEN UNIVERSITY, IWO
PURE AND APPLIED BIOLOGY PROGRAMME
COURSE CODE: BLY 102
COURSE TITLE: GENERAL BIOLOGY II
SEMESTER: SECOND
TITLE: GENERAL CHARACTERISTICS AND STRUCTURE OF PLANT DIVISION
1. Division: Thallophyta
These are plants that do not have well-differentiated body form (i.e. thalloid). They are found both
in terrestrial and aquatic habitats, but are predominantly aquatic; freshwater or marine. It has only
one subdivision Algae. Examples are Spirogyra, Ulothrix, Cladophora and Chara. Various types
of fungi like yeasts and moulds which do not have chlorophyll are also included in this group.
Sub-division: Algae
• They are autotrophs
• The body is simple and not well differentiated (i.e. they possess thalloid body form)
• The form and size of algae are variable. Chlamydomonas is microscopic unicellular algae.
Volvox is in colonial form. Ulothrix and Spirogyra are filamentous.
• They are further classified as green algae, red algae and brown algae. Red and brown algae are due
to the presence of accessory photosynthetic pigments.
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Clamydomonas
Volvox Spirogyra
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2. Division: Bryophyta
The plant body in this group is commonly differentiated to form stem and leaf-like structures.
Roots are not presents, but a small root-like structure called rhizoid is present. They are called the
amphibians of the plant kingdom because they grow in moist areas. It has embryo stage in its
developmental process. The sex organs are multicellular. Male sex organ is called antheridium and
produces antherozoids. Female sex organ is called archegonium and produces a single egg.
Examples are Moss (Funaria) and Marchantia (Liverwort), Anthoceros, Riccia
Diagram of a Moss Showing the sporophyte and gametophyte
A Moss Plant
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Liverwort Riccia
3. Division: Pteridophyta
In this group, the plant body is sporophyte and can be differentiated into roots, stem and leaves. It
is the highest group of cryptogams. They have a specialized tissue for the conduction of water and
other substances form one part of the plant body to another. Hence they are also called vascular
cryptogams. Seeds are absent and they produce naked embryo called spores.
Sporophytes bear sporangia which produce spores. On germination, this spore gives rise to
gametophyte called prothallus. Prothallus bear male sex organ antheridia and female sex organ
archegonia. Some examples are Marsilea, Ferns, Selaginella, Equisetum, Pteris, Adiatum,
Lycopodium and Horsetails.
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Selaginella kraussiana
Selaginella kraussiana Fern (Maiden hair)
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4. Division: Spermatophyta
This is a division of seed producing plants. The seed contain embryo that contains reserve food
(i.e. cotyledon) for future growth. Its main plant body is sporophyte and can be differentiated into
stem, leaves and roots. Male and female gametophytes are distinct. They have a well-developed
vascular system throughout the body. Spermatophyta has two sub-divisions – Gymnospermae and