Question

Anther idia Fertilization Archegonia O O o Spores Meiosis
Phylum Hepatophyta: Liverworts

Like the moss, liverworts begin as a haploid spore. As a liverwort spore germinates, it develops into a flat, lobed, leaf-like structure called a thallus. The thallus grows prostrate with the ground’s surface, forming rhizoids that anchor it in place.

Liverworts reproduce asexually primarily by fragmentation; however, some liverworts may also reproduce asexually by bundles of tissue called gemmae. In many liverworts, gemmae develop in small cup-like structures called gemmae cups. Splashed from the cups by rain, gemmae landing in a suitable environment will germinate and grow into new thalli.

In sexual reproduction, vertical reproductive structures sprout from the gametophyte. The female reproductive structure, resembling a tiny palm tree, consists of an archegonial head borne at the end of a stalk-like archegoniophore with egg-containing archegonia hanging down. The male reproductive structure consists of sperm-producing antheridia located within an antheridial head borne on the end of an antheridiophore. Like mosses, liverworts require water as a medium for the motile sperm to reach the egg. Within the archegonium, the zygote develops into an embryo, or young sporophyte. The sporophyte consists of a foot, a short seta (stalk) and a capsule containing diploid spore mother cells. Following meiosis of the spore mother cells, a mature capsule contains both haploid spores and elongate, narrow cells called elaters. The elaters are exposed to air as the capsule splits open. As the elaters dry, their coiling and twisting action aids in spore dispersal from the capsule. These spores germinate into new thalli and the cycle of alternation of generations continues.

Activity D: Label the life cycle of the liverwort using the following terms:

spores

thallus

gametophyte

rhizoids

antheridia

archegonia

sporophyte

haploid

diploid

I'm not sure if the ones I labled are right either!

Answer 1

You have named the spores correctly. The rest of the parts are as labelled. Due to space constraint it might be a little crowded and confusing.

The lifecycle follows thus using the labelling terms starting fromSporophyte:

Sporophyte( has a foot, seta and a capsule containing diploid mother cell) ----------->undergoes meiosis------>haploid spores released under favourable conditions----------->Forms thallus--------->forms rhizoids that are structures that anchor the plant in the soil medium---------->thallus can produce either female gametophyte or male gametophyte.

Female gametophyte: Consists of archigoniophore which form egg containing archegonia

Male gametophyte: Consists of antheridiophore which form antheridia

The sprem from the male will fertilise the egg and the zygote formed will develop into an embryo. This embryo is called sporophyte and will have the diploid mother cells inside the capsule part of its structure which will form haploid spores after meiosis and thus the life cycle continues.

Hope this was helpful.