Download Session B

Science Year 5
Biology Strand: Living things and their habitats
This plan makes reference to session resources that can be downloaded from https://www.hamilton-trust.org.uk/browse/science/y5/livingthings-and-their-habitats-y5-new-curriculum/109740.
Session B
Programme of study: Describe the life process of reproduction in some plants and animals
Non-flowering plants
Working
scientifically
Record data using scientific diagrams, drawings and labels
Samples of seaweeds, mosses, liverworts, ferns, conifer twigs with leaves & cones if available locally.
Sketching pencils, hand lenses. Access to internet
Whole class teaching: Remind children that they found out in Y4 that plants can be divided into different categories. The plant
kingdom is divided into plants that do have a water-transport system (vascular system) & those that do not. Some scientists think that
non-vascular plants are not true plants & should not be in the plant kingdom. Vascular plants are split into 2 groups – flowering plants
(that produce seeds) & non-flowering plants that don’t produce seeds.
Resources needed
In the past scientists classified algae as simple plants. Like all plants algae can make their own food by photosynthesis, but they do not
have a water transport system. Some scientists think algae should be classified as protists (another kingdom like plants & animals in
classification, which children will learn more about in Y6) & not plants. Algae do not have separate roots, stems and leaves but instead
they have a single structure called a thallus. Algae live in water or where it is damp & are able to absorb water (& nutrients & gases)
everywhere on their surface. Some simple algae consist of only one cell – see session resources. Seaweeds are algae – show children
structure of a common variety - kelp. The holdfast looks similar to a root, but does not have the same function & the stipe looks like a
stem, but again does not have the same function. There are three main types, classified by their colour – green, red & brown. Show
children some examples if available or pictures in session resources.
Mosses and liverworts have more complex structures than algae. They grow in damp, shady places. They are non-vascular plants. They
do have fine, root-like structures that absorb water & nutrients & help anchor them in place. Most mosses have upright shoots with
spirals of tiny leaf-like structures. Liverworts have a thin, flat body called a thallus which grows flat on the soil or on the surface of still
water. Show children examples or pictures in session resources.
Algae reproduce in a two-stage process (called alternation of generations): to start with male & female cells join to form an embryo. The
embryo then develops into an alga that produces spores. The spores are released & germinate to form new plants. On the seaweed
diagram the term haploid refers to half the number of chromosomes (again like eggs & sperm) compared to the parent plant which is
diploid. Mosses & liverworts also reproduce in a two-stage cycle. The male & female cells (like eggs & sperm) join to form structures
called sporophytes. The sporophytes produce tiny spore in capsules held above the plant on thin stalks (see session resources).
Algae, mosses & liverworts can also reproduce asexually. Unicellular algae can split into two to form two ‘daughter’ cells – both identical
to the original organism. Some seaweeds produce zoospores which swim off, anchor themselves to a surface & grow into new
seaweeds. Some pieces of seaweed that get broken off in rough seas can develop into a new plant identical to the parent plant too.
Pieces of moss that are broken off the parent plant can develop into new plants too. Small buds on moss plants called gemmae can
break off & form new plants. Liverworts produce structures called gemmae cups (session resources), which produce balls of tissue called
gemmae. When rain splashes into the cups, gemmae are released & can grow into independent plants.
Ferns (session resources – the sporophyte) are vascular plants but they reproduce using spores too. The leaves of ferns (these are the
sporophytes in the alternation of generations) are called fronds. To start with they are tightly curled (called fiddleheads), but they
gradually uncoil as they become more mature. On the underside of the fronds there are clusters of small, brownish structures called
sporangia (cluster called sorus – plural sori). Pass a fern frond around if available. The spores are released & dispersed & then germinate
to form a flat, heart-shaped plant (gametophyte) called a prothallus. Fern prothalli produce male & female organs on their underside.
When it rains sperm are carried to the eggs & fertilisation takes place. The fertilised eggs grow into the leafy plants ferns (session
resources).
Another large group of non-flowering plants are the gymnosperms (from the Greek for ‘naked seed’).The seeds are ‘naked’ because they
are not contained in an ovary as in flowering plants. Most gymnosperms are long-lived trees or bushes - conifers (pine trees or fir trees).
They are vascular plants. Most are evergreen with needle-like or scale-like leaves & they bear cones, e.g. Scots pine, giant redwoods,
larches, Douglas fir, yew trees (arils instead of cones), etc. (session resources). Look at conifer life cycle in session resources too. Each
cone is either male or female. Pass a cone around for children to look at.
Group activities:
Independent: Make a careful observational drawing of a seaweed, moss, liverwort, fern &/or parts of a conifer depending what is
available. Label the structures that are visible. Use hand lenses to study the details & perhaps draw an enlarged section.
Independent: Draw the life cycle of a seaweed, moss, liverwort, fern or conifer.
Independent: Visit http://studyjams.scholastic.com/studyjams/jams/science/plants/mosses-and-ferns.htm & watch the slide show &
tackle the quiz.
Independent: Water the seedlings & the plant propagation specimens from Session A if necessary. Make notes about any signs of
growth including date. Measure the height of the seedlings.
© Original plan copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users
We refer you to our warning, at the top of the You Will Need document, about links to other websites
Science Year 5
Biology Strand: Living things and their habitats
Plenary: Fungi – mushrooms & toadstools are not considered plants either – they have their own Fungi Kingdom. A very old (has not
changed) tree called the maidenhair tree (Gingko) is not a flowering plant but they are like the gymnosperms mentioned above.
Horsetails, which are also very ancient plants reproduce by spores which are produced in cone-like structures at the tips of the stems.
They grow from underground rhizomes & are vascular plants. Gardeners don’t like them because they are difficult weeds to eradicate.
I can:
1. Understand that plants are classified into non-vascular & vascular types and that the latter are further divided into flowering and nonflowering types.
2. Describe the life cycle of some non-flowering plants.
3. Explain that some plants can reproduce asexually.
© Original plan copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users
We refer you to our warning, at the top of the You Will Need document, about links to other websites