Experiment 3 Bio300

EXPERIMENT 3.1 PREPARING A SLIDE OF PLANT TISSUES OBJECTIVES

1. To make a thin slice by using hand-cutting method 2. To prepare, stain stain and make a aslide aslide of plant plant sapmle 3. To illustrate the observation observation of of plant sample

MATERIALS

Samples  A young dicot  Apparatus Compound microscope Slide and coverslip Chemicals Eosin

METHOD

1. About 2 cm of of a young root of of balsam is obtained. It is placed on microscope slide or plate 2. 2. The root is cut very very thin through through the region region of maturation 3. The thinnest section section is selected and it is transferred to a slide that contain a drop of water. 4. The slide is observed observed by using using compound microscope. microscope. The observation observation is sketched and labelled in the space provided in Table 3.1 5. The tissue system in young root system; vascular vascular cylinder is identified. 6. Step 1 until until 4 is repeated repeated by using stem of dicot.

EXPERIMENT 3.2 PREPARING A SLIDE OF INSECT TISSUES OBJECTIVES

1. To make a slide by using squash technique 2. To prepare,stain and make a slide on insect sample 3. To illustrate the observation of insect sample. MATERIALS

Sample  A male locust (Example: locust, Valanga nigricornis)

 Apparatus Dissecting and compound microscope Slide and cover slip Small dissecting dish Pin Glass rod Hotplate or Bunsen burner Filter paper

Chemicals  Acetic-orcein Canada balsam

METHODS

1. A freshly killed male locust was pinned out on a small dissecting dish with dorsal side uppermost. The wings were pinned out on each side. 2. The abdomen was opened up by a mid-dorsal longitudinal cut. The body wall was pinned back. 3. The testis was identified by using a dissecting microscope. Together with fat, these made up an oval body lied above the gut in abdominal segment (segments 5 and 6). The testes were transferred on a microscope slide. 4. The fat (yellow) was removed as much as can, only the white tubules of the testes were leaved. Two or three were sufficient. 5. Several dropped of acetic-orcein stain was added and was put on cover slip. 6. Then, was covered with filter paper and was squashed gently. This helped the chromosomes spread. 7. The slide was warmed up on a hot plate or Bunsen burner for about 10 seconds for the staining intensified. 8. The slide was observed using microscope, and specimen was sketched. A photo was taken using digital microscope. The stages of meiosis were examined. Chromosomes were drew and labeled in Table 3.2. The slide was washed with a jet of water for the excess dye removed, then air dried the material once again and was mounted in Canada balsam or similar media.

DISCUSSION

In Experiment 3.1, we have to make a thin slice of plant tissue sample (Canada balsam) by using hand-cutting method and we also have to prepare it as a slide that to be observed under light microscope. During the experiment, we took two part of the plant, which are soft stem and root. We chose soft stem as the sample because it makes the cutting method to be easier. As a result, we can observe the structure of xylem and phloem in both part of the tissue. The characteristics of water-carrying cells(xylem) are it is in the middle of the cell. The xylem of most vascular plants included tracheid, tube-shaped cells that carry water and minerals up from roots. Furthermore, food-carrying cells(phloem) placed at the outer layer of the cell. The phloem has cells arranged into tubes that distribute sugars, amino acids, and other organic product. Roots are organs that absorb water and nutrients from the soil. Roots also anchor vascular plants, hence allowing the shoot system to grow taller. In Experiment 3.2, we have to make a slide of incest’s testis (grasshopper) by using squash technique and preparing a slide for observing under light microscope. First, we have to choose a male grasshopper to be examined. Then we have to pin it on the blue wooden board. Next, by using dissecting knife, we cut of longitudinally its abdomen and the testis (needlelike shape) is taken out by using forceps and it was placed on the glass slide. Then we added several drops of acetin-orcein stain and put on the cover slip. The observations were portrayed it in the Table 3.2. The precautions steps that we should engage in the slide-making process are we have to cut as thin as possible the plant tissue so that it will be easier t o observe under light microscope. Furthermore, for experiment 3.2, once should cut the insects abdomen longitudinally using a knife. Besides that, during preparing a slide, it has to be warmed up 10 s on Bunsen burner accurately.

CONSLUSION

Using hand-cutting method for making a thin slice of tissue sample is not the best way as the thinness of the tissue probably cannot be obtain accurately.

INTRODUCTION

Examining thin section of specimens using light microscope will be the major tool to study cells, tissues and organ morphology. Histology involves the preparation of the tissues for examination using a microscope. Light microscope utilizes specific arrangements of lenses to magnify an image. An electric bulb is the light source used to illuminate the tissue section. The image is further magnified by the ocular lens of the eyepiece. This lens focus the image on the retina of the eye. The total magnification of the image depends in the magnifying powers of the objectives lens and that of the ocular lens. Quality of the image depends not only on magnifying capability of the lens but also on its resolution. The resolution means of the lens to show that two distinctive objects are separated.