BIOLOGY:: CH-3 Plant kingdom

pteridophytes include

horsetails and ferns

pteridophytes used as

medicine, soilbinders, ornamentals

soil binders

have roots to bind soil
prevent soil erosion

first terrestial plants to have vascular tissue

pteridophytes

habitat of pteridophytes

cool, damp, shady places
some flourish well in sandy soil

dominant phase of pteridophytes

sporophyte

sporophyte differentiated in roots stem and leaves

pteridophyte

well developed vascular system in

sporophyte of pteridophytes

types of leaves found in pteridophytes

macrophyll and microphyll

microphyll in pteridophyte example

selaginella and equisetum

macrophyll in pteridophyte example

ferns

sporangia

found on leaf- like appendages called sporophylls

sporophyll present on

sporophyte

strobili or cones

in some cases, sporophyll forms distinct compact structures

strobili or cones example

selaginella and equisetum

spore mother cells in sporangia

produce spores by meiosis

prothallus

spores germinate to give rise to inconspicuous, small but multicellular, free living, photosynthetic thalloid gametophyte called prothallus

gametophytes favourable condition to grow

cool, damp, shady place
water for fertilisation

spread of living pteridophyte restricted

due to their specific restricted requirement and the need for water for fertilisation, the spread of living pteridophyte is limited and restricted to narrow geographical area

antheridia and archegonia present on

gametophyte, prothallus

male gametes release

from antheridium, to the mouth of archegonia

fertilisation

in archegonium

zygote formation in

archegonium

zygote produces

well differentiated, multicellular dominant sporophyte

homosporus

plants in which spores are of similar kind
most pteridophytes and all bryophytes

heterosporus pteridophytes

selaginella, salvinia, azolla, marsilea

the precursor to seed habit

plant must be heterosporus

precursor to seed habit first originated

pteridophytes

male gametophyte

microspore

female gametophyte

megaspore

why heterosporus pteridophytes don’t produce seeds

the female gametophyte leaves main plant as soon as zygote formation occurs

classes of pteridophytes

psilopsida, lycopsida, sphenopsida, pteropsida

psilopsida ex

psilotum

lycopsida eg

selaginella, lycopodium

sphenopsida eg

equisetum

pteropsida eg

pteris, dryopteris, adiantum, pteridium, azolla, marsilea, salvinia