英文版生物涡虫再生实验报告模版

姓名班级学号实验日期2014

科目普生实验实验名称Regeneration in Planarian

合作者指导教师成绩

LAB 8: Regeneration in Planarian

Introduction:

Planarian (flatworm Dugesia japonica) is one of a series of animal species that have the ability to re-grow their body parts when damaged. When its body is elongated, it is soft, leaf-shaped and ciliated. It has spade-shaped head with two eyes and tentacles while the tail is pointed. Its mouth is even on the ventral. When it comes to its inner structures, it has no body cavity (coelom), so its pharynx may ends in an intestine. It usually is 3 to 15 mm long, but it can also grow to more than 30 cm. It moves by swimming like slugs, tending to seek food which includes protozoans, tiny snails and worms at night as carnivorous creature.

Planarians are hermaphrodites and their reproductive organs start to develop in early autumn, but they cannot inbreed. Most of these individuals are able to fully develop, while some may be abnormal. And because of planarians’ remarkable ability to regenerate lost parts, they are often used in biology experiments.

In this experiment, we will have an opportunity to observe and recognize some of the basic features of planarians. We will be taught to use scientific approach to hypothesize how planarians respond to fragmentation. The planarian will be worked as model.

Materials and methods:

Materials:

Stereoscope (Nikon), Hand lenses, Petri dish with frozen water, Knife, Tweezers, Droppers, Filter papers, Planarians.

Methods:

Part Ⅰ: Observe the planarian.

⑴Use hand lenses to have a close observation on planarian, and record what are seen in table T-1.

⑵Identify the following features and make notes accordingly: color, shape, movement, length,

symmetry, visible body parts, responses to light, food and flipping the animal upside down.

⑶Summarize what we have found out, and try to find connections between different aspects of

planarian’s biology.

Part Ⅱ: Exploring regeneration in Planarians by cutting a Planarian.

⑴Label a petri dish with mark pen.

⑵Place a Planarian on wet filter paper placed on top of bed of frozen water in a petri dish, so that

it can be relatively still.

⑶Bisect the Planarian into two pieces, like

⑷Use a dropper to dislodge the Planarian off the filter paper and into the labeled petri dish. Fill

the petri dish about half full with water.

Part Ⅲ: Observe regenerations which come from trisection of Planarian over time, based on the samples provided by teachers.

⑴Cut a Planarian how we want to, place the parts into the labeled petri dish, fill it about half

full with water.

⑵Observe at different time Points (2 hours, 1 day, 2 days, 3 days, 7days), and make notes about

the changes in color and the progression of the regenerating parts in table T-2.

Results：

Part Ⅰ:

The shape of Planarian benefits to its living in water, such as a spade-shaped head. And when feed it meat, it will approach to the objective slowly; then if nothing threaten it, it will reach out its

mouthpart to the food.

When it moves, it will try its best to avoid light source.

Part Ⅱ: (Based on the series of Figure 2)

After being cut to two parts, they can both still moves in petri dish. Relatively, the part of head is more active than the part of tail. The frozen water does make the Planarian remain relatively still, so that it is easier to cut. [The development of these two parts will be given in Table T-2].

Part Ⅲ:

In the teacher’s samples are trisection of Planarian, the time is 4.30, 5.4, 5.5, 5.6, 5.7 respectively, when they are observed on 5.7.

Besides the sample from Part Ⅱ, in our samples, the Planarian is cut from head to tail (bisect), like Table T-2 ( As shown in the series of Figure 3)