Experiment 4 Report

EXPERIMENT 4 GYMNOSPERMS AND ANGIOSPERMS

INTRODUCTION 1. To investigate the vegetative morphology and reproduction of one type of gymnosperm, Pinus

merkusii. 2. To make overall morphological comparisons of four groups of gymnosperms. 3. To investigate the reproductive morphology of two types of flowering plants, Lilium sp. and

Hibiscus sp. 4. To make overall morphological comparisons of gymnosperms and angiosperms.

PRACTICAL CONTENT 1. Morphology of Pinus merkusii, an example of a gymnosperm.

a) Vegetative characteristics of Pinus sp. -

The short, long shoots and the fascicle were observed.

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The woody structures of gymnosperms from the slides or pictures exhibited were observed, especially cell types and bordered pits.

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A diagram for every observation made above was drawn and all the important structures were labeled.

b) Reproductive structures of Pinus sp. -

The male and female cones of the pines tree provided were observed.

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For the male cone, the position of the megasporangium in the megasporophyll was observed.

2.

Diagram of both reproductive organs were drew and labeled.

Comparative studies of the four main groups of gymnosperms using Cycad, Ginkgo, Gnetum and Pinus as example -

Based on the materials provided (including life specimens, pictures and diagrams), comparisons between the four groups of gymnosperms using the following format as a guide were made:

a). Morphology b). Height c). Vegetative characteristics – leaf and stem d). Reproductive characteristics – cone (if present) and seed 3.

Microscope slides of the following structures were observed: a). Microsporangium b). Microphyll c). Male and female cones

d). Horizontal section of gymnosperm seed ANGIOSPERM 4. Morphology of two examples of the flowering plants, Lilium sp. and Hibiscus sp. Both flowers were dissected to show the sepal, petal, pistil and stigma. -

Horizontal section through the anther of the Lilium sp was made and a slide (using the dye 'methyl green') was prepared. The pollen on the slide that I had prepared was observed.

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A horizontal and vertical section of the pistil of the Hibiscus sp. to show the ovary and ovule were made.

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Developed pollen grains (by immersing them in sugar solution at 5-10% concentration for a few hours) were provided. The developed pollen grains under a microscope were observed and a pollen grain was drawn, with a pollen tube and three nucleus inside.

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Prepared slides of angiosperms ovary were observed. By observing a few slides of angiosperm ovary, the following structures were able to observed: a). Funicle b). Integument c). Micropyle d). Nucellas e). Embryo A diagram that would show all these structures were drew.

5.

Floral diagrams for two types of flowers that I had dissected were drawn.

The characteristics of gymnosperms (that I had observed in section 1, 2 and 3 above) and angiosperms were compared, particularly with regards to the following aspects: a). seed structure b). gymnosperm cone and angiosperm flower

EXPERIMENT 5 STEM,LEAFAND ROOT

1.0.

Macroscopic structures of stem: Cut across a mature tree trunk to differentiate two areas namely:

(a)

Bark: All tissues outside the vascular cambium (phloem, cork cambium and cork) were composed.

(b)

Wood: In general was divided into:

i.

Sapwood which is the outer layer of the wood. It is the lighter coloured wood, made up of still functioning xylem cells for sap (water and mineral) movement and for food storage.

ii.

Heartwood which is the inner layer of the wood. It is the darker coloured wood, made up of nonliving cells, mostly for mechanical support.

1.1

(a)

The section of tree trunk provide was drew and labeled:

(b)

What will happen to a three when a strip of 5 cm of outer layer is remove from the circumference of the tree trunk?

2.0

Stem adaptation

a)

Stems may be adapted for functions other then the main ones namely:

i)

mechanical support

ii)

transportation of food materials

iii)

production of new plants

b)

From the examples given, stem adaptations were drew and labeled as follows:

2.1

Stem above ground level:

Adaptation for protection: Example: Diagram: Adaptation for cladophyll: Example: Diagram: Adaptation for climbing: Example: Diagram: Adaptation for twinning (tendril): Example: Diagram:

2.2

Underground stem adaptation:

Rhizome: horizontal stems that grow below ground, often near the surface of the soil. Example: Diagram: Tuber: swollen stem due to the accumulation of food. Example: Diagram: Corms: resemble bulbs but differ from them in being composed almost entirely of stem tissues Example: Diagram: Bulb: large buds surrounded by fleshy leaves, with a small stem at the lower end. Example: Diagram:

B.

LEAF

1.0

Morphological Shapes and Diversity of Leaf

Morphology or the external appearance of leaf (including leaf venation, leaf shapes, apex, margin and base of leaf), leaf arrangement on the stem (leaf phyllotaxy; for example whorled, alternate and opposite), and many more leaf characteristics that could be identified and differentiated with regards to the leaf form. These leaf characteristics can be used in the classification of species. From all the leaf demonstrated in this practical, diagrams of each of the following leaf characteristic (one for each leaf characteristic) were labeled. a)

Simple cordate leaf: Leaf name: Diagram:

b)

Simple peltate leaf: Leaf name: Diagram:

c)

Simple linear leaf: Leaf name: Diagram:

d)

Palmately compound leaf: Leaf name:

Diagram: e)

Paripinnate compound leaf: leaf name: Diagram:

f)

Imparipinnate compound leaf: Leaf name: Diagram:

g)

Opposite leaf arrangement: Leaf name: Diagram:

h)

Alternate leaf arrangement: Leaf name: Diagram:

i)

Whorled leaf arrangement: Leaf name: Diagram:

j)

Spiral leaf arrangement: Leaf name:

Diagram: 1.1

How would you differentiate between a leaf and a leaflet? Generally, we can differentiate between leaf and leaflet based on its shaped. Normally, leaf's shape was bigger in size than leaflet. Besides, leaf also

1.2

The morphological form and anatomy of leaf is very much influenced by the environment. Depending on their living environment, plants can be divided into three types:

a)

Hydrophytes: plants living in wet or aquatic area. Example: Nymphaea sp.

b)

Xerophytes: type of plants living in dry arid area Example: Oleander sp.

c)

Mesophytes: plants living in areas not too dry or too wet. Example: Lantana sp.

Aim To study the effects of environment on the leaf anatomy, observe a cross-section of leaf from Nymphaea sp., Oleander sp. and Lantana sp., prepared under the microscope. a)

Does a leaf have vascular cambium?

b)

By knowing the living environment of these different plant species, elaborate on the special characteristics found on the leaf related to their living environment:

Hydrophytes: Xerophytes: Mesophytes: 2.0

Leaf Adaptation

The main function of leaf is in the process of photosynthesis and transpiration. Apart from the main function, leaf is sometimes adapted to perform other functions. Examples of leaf adapted for: a)

support, this could be seen by presence of tendrils.

b)

catching insect, by having cup-like shape or hairs sensitive to touch.

c)

reproduction, by having meristematic cells able to produce new shoots that will go on to become new individual plant.

d)

food and water storage, especially found on types of plant living in dry area or areas where water is scarce (for example succulent plants, having leaf storing food and water).

e)

floatation, for plant living on the water surface, their leaf in general will have air openings on tissues used for floating, usually found on the leaf petiole.

f)

protection, for example having leaf completely or partly modified as thorns.

From the materials demonstrated regarding leaf adaptation, the types of leaf to one of the many functions of leaf mentioned above were related.

Diagram of the leaf provided adapted to function for was drew and labeled: a)

Support (tendril) Leaf name: Diagram:

b)

Catching insect Leaf name: Diagram:

c)

Reproduction Leaf name: Diagram:

d)

Food and water storage Leaf name: Diagram:

e)

Floatation Leaf name: Diagram:

f)

Protection Leaf name: Diagram:

C.

ROOT

1. Types of root Root, can be divided into different types as follow: a)

tap root: thick main root (primary root from the embryo) grows straight downwards and from it, thinner branch roots arise.

b)

fibrous root: large number of roots of similar size developing from stem nodes.

c)

adventitious root: grow from stem or leaf.

From the specimens provided, diagram of root parts according to type were drew and labeled. Labeled diagram of the root provided were drew, adapted for functions as: a)

Tap root, example: Diagram:

b)

Fibrous root, example: Diagram:

c)

Adventitious root, example: Diagram:

2.

Root, apart from their main function for support and food absorption is adapted for other special functions as follow:

a)

Pneumatophore root: breathing roots that facilitate the exchange of gases, grow upwards from underground.

b)

Prop root: grow from the above ground stem into the soil, usually for mechanical support.

From the specimens provided, labeled diagrams of adapted root were drawn. a)

Pneumatophore root, example: Diagram:

b)

Prop root, example: Diagram: