Class 11 Biology Identification Of Virtual Specimens With Their Characteristics Experiment

Introduction

Like humans are unique from one another,every species has distinct characteristics.Specimens are living organisms that are beneficial for biological research.Specimens are used for identification and examination of species.Microscopic organisms are viewed through slides in microscope.Classification and identification are crucial factor as they enable us to perceive the connections and relationships between things better.Classification deals with different features.For instance, the two kingdoms of plants and animals make up the initial division of living things in the kingdom classification scheme. The classification system underwent changes as microorganisms were identified . Nowadays, a five kingdom classification is frequently employed.

Table of Contents:

• Aim

• Apparatus Required

• Theory

• Procedure

• Observation

1. Classification

2. Diagnostic features

3. Features

• Result

• Precautions

• Lab Manual Questions

• Viva Questions

• Practical Based Questions

• Summary

• Frequently Asked Questions

Aim:

To identify species with characteristics by observing specimens/slides/models.

Apparatus Required:

1. Slides of amoeba

2. Hydra

3. Liver Fluke

4. Ascaris

5. Earthworm

6. Leech

7. Models,photographs or specimens of prawn

8. Silkworm

9. Honeybee

10. Snail

11. Starfish

12. Shark

13. Rohu

14. Frog

15. Lizard

16. Pigeon

17. Rabbit

18. Microscope.

Theory:

A scientific tool that aids in the observation and interpretation of the natural world by biologists is the classification of species into recognisable and distinct entities. The pioneering work of Carl Linnaeus, who used binomial nomenclature and external morphology to distinguish between species, is still used today. The principles of current taxonomy are more based on evolutionary links and features. For example:There are 34 sections in the leech body, each having a small anterior. Earthworms have a muscular, segmented body.

Procedure:

• Observe the specimen and identify it .

• For microscopic organisms,adjust the microscope to focus the slide clearly.

• Observe the slide and identify the organism.

• Write down the features of the specimens/slides.

Observation:

• Amoeba

Classification

Phylum -Protozoa

Class -Sarcodina

Diagnostic Features

• Ectoplast, the outside section of the cytoplasm, and endoplast, the interior portion, make up the cytoplasm.

• Osmotic pressure is maintained by a single nucleus and a simple contractile vacuole.

Features

• One-celled microscopic organisms that are transparent and invisible to the naked eye.

• The development of transient cytoplasmic extensions known as pseudopodia, which are amoebas' most unique morphological feature

• Both for moving around and for catching food, these fake feet are used.

Amoeba

• Hydra

Classification

Phylum -Cnidaria

Class -Hydrozoa

Diagnostic Features

• Hydra is a coelenterate with a tubular or cylindrical body that resembles polyps or polypoids.

• Their bodies are small tubes with several tentacles on one end.

Features

• A hydra spends the majority of its existence inactively waiting for food to come to it rather than actively seeking it out.

• having extremely extendable tentacles that can reach a great distance in the surrounding water, in radial symmetry.

• The gastrodermis is the inner layer while the epidermis is the outer layer.

Hydra

• Liver Fluke

Classification

Phylum - Platyhelminthes

Class - Trematoda

Diagnostic Features

• Flukes are shaped like leaves, and they have an acetabulum, or ventral sucker, that can be used to attach to host tissues. Flukes also have an oral sucker surrounding their mouth.

• The tegument covers the body. They are hermaphrodites and have full reproductive systems for both sexes.

Features

• They can be found anywhere and are between 5 millimetres (0.2 inches) and several centimetres in size.

• They eat mostly blood and have basic digestive systems.

• There is no cavity in the body.

Liver Fluke

• Ascaris

Classification

Phylum -Aschelminthes

Kingdom - Nematoda

Diagnostic features

• Males are smaller at 15-31 cm and typically have curled tails, whilst females are 20-35 cm long with straight tails. 

• Three lips are present on the front end of the body in adults of both sexes.

Features

• Ascaris has a pseudocoelom, also known as a false cavity, in which mesoderm-derived tissue only partially lines the cavity-filled with fluid. Metamerism, which refers to the ability to repeat segments, is not present in worms.

• Most free-living roundworm habitats are located in freshwater environments.

• Humans are one of the many hosts for parasitic roundworms.

Ascaris

• Leech

Classification

Phylum - Annelida

Kingdom - Hirudinea

Diagnostic Features

• They are often dark in colour, frequently brown, occasionally black, or deep green.

• Other species have spots and stripes, while some have no markings at all.

Features

• The segmented worms known as leeches have suction cups on each end.

• 33 segments, or somites, make up their 33-segmented body. Further divisions into annuli or rings are made for each segment.

• Leeches adopt a distinctive wave-like swimming technique to move across the water.

Leech

• Earthworm

Classification

Phylum - Annelida

Class - Oligochaeta

Diagnostic Features

• The earthworm has a thin non-cellular cuticle covering its body wall.

• A layer of the epidermis, two layers of muscle, and the coelomic epithelium (inner layer) are wrapped beneath this cuticle.

Features

• Earthworms have identical bodies on both sides, which is referred to as bilateral symmetry. 

• They lack scales and limbs. 

• Some worms have light-sensing organs, and many have sense organs that allow them to detect chemical changes in their surroundings.

Earthworm

• Prawn

Classification

Phylum -Annelida

Class   -Crustacea

Diagnostic Features

• There are six different, moveable segments that make up the abdomen.

• Each segment is covered in a tough cuticle that is divided into a ventral sternum, two lateral pleurons, and a dorsal, convex tergum.

• A median triangular component known as the telson is located at the end of the abdomen. There are no appendages on it.

Features

• Prawns are crustaceans that have a shell, three pairs of clawed legs, five pairs of walking legs, and a tail. The average size is from 15 to 20 cm, but it is varied.

• The body is elongated, with an anterior cephalothorax and a posterior abdomen.

• Branchiostegite, or gill cover, is the part of the carapace that hangs loosely on the sides and encloses the gills.

Prawn

• Silkworm

Classification

 Phylum -Arthropoda

 Class -Insecta

Diagnostic Features

• The wings are cream in colour with dark veins that reach the edges.

• has a body with dense spikes.

Features 

• Bombyx mori, which refers to "silkworm of the mulberry tree," is the scientific term given to silkworms.

• Silkworms start off as worm-like larvae with three separate insect body components. The silkworm eventually transforms into a scaly, four-winged moth after spending some time in a cocoon.

• Larvae that have just hatched are roughly 2 to 3 mm (0.08 to 0.12 inch) long.

Silkworm

• HoneyBee

Classification

Phylum -Arthropoda 

Kingdom-Insecta

Diagnostic Features

• The colour of the head and thorax, or middle, varies depending on the strain and is slightly bristly.

• On top of the head are two big compound eyes and three small eyes, or ocelli.

Features

• Their bodies are thick and oval.

• There are two female castes and two sexes of honeybees, male and female. The two female castes are known as workers, which are larger than workers and are defined as females who do not reach sexual maturity. Only in the early summer are the males, or drones, present. They are bigger than the workers. The drones lack stingers, although the workers and queens do.

Honey bee

• Snail

Classification

Phylum - Mollusca

Class - Gastropoda

Diagnostic Features

• A large, spirally coiled, dextral spherical shell surrounds the body.

• The shell is a wide cone that is spirally wound around a central axis, the columella.

• The apex of the shell is its topmost point.

• The whorls get bigger starting from the apex, with the body whorl being the biggest.

Features

• A family of big freshwater snails  with a gill and an operculum are known as apple snails. These snails have lungs and gills that function as independent respiratory organs and are divided by the mantle cavity.

• The operculum has concentric growth rings surrounding its core or nucleus.

Apple snail

• Star Fish

Classification

Phylum  -Echinodermata

Class -Asteroidea

Diagnostic Features

• The radial shape of a  starfish, which frequently has five limbs spread apart from a central body .

• They lack a backbone and have hard plates under their skin as well as mouth present in the middle of their ventral surface.

Features

• They move around by using thousands of tiny tube feet on the underside of each arm. A starfish's circulatory system is made of sea water rather than blood.

• Water is pumped into its body and through tube feets. A starfish can grasp and release rocks, coral, or the sand in order to move itself forward by pumping water into the tube feet in a rippling effect down its arms. Starfish can hold on to their prey firmly because of their tube feet.

• A unique characteristic shared by the majority of sea stars is the capacity to devour prey external to their bodies.

Starfish

• Shark

Classification

Phylum - Chordata

Superclass - Pisces

Class - Chondrichthyes

Diagnostic Features

• Long (equal to or longer than the head), broad-tipped pectoral fins.

• Light blue to white below, dark blue to bluish-black above.

• eyes are big.

• The mouth region and snout's conical underside are dusky or bluish-black.

Features

• Sharks have denticles all over their body, are cold-blooded, and breathe through their gills (tooth-like scales). Several essential mammalian characteristics are also absent in sharks: They lack a neocortex (part of the brain involved in perception and thought, among other things) milk production, and hair growth.Sharks are fish.

• Sharks lack skeletons. Instead of having a bone skeleton, they have soft cartilage. 

• Sharks can move through the water more easily and consume less energy while swimming because cartilage is more flexible and lighter than bone.

Shark

• Rohu

Classification

Phylum - Chordata

Class - Osteichthyes

Diagnostic Features

• The mouth is smaller and the head is triangular. The rohu's body is shaped like a spindle. Its body colour is silvery on the ventro-lateral sides and blackish on the dorsal side.

Features

• bone cavities.

• Complete separation of oxygenated and deoxygenated blood in a four-chambered heart.

• They have a sleek body with a gaping, huge oval.

• Cycloid scales cover their entire body.

Rohu

• Frog

Classification

Phylum - Chordata

Class - Amphibia

Diagnostic Features

• They have scars that cover the eardrums behind their eyes. On the other hand, toads have smaller legs.

• Moist skin that is  sticky.

Features

• Frogs have outwardly facing eyes, no tail, and powerful, webbed hind feet that are designed for swimming and leaping.

• A few frog species, like poison dart frogs, are particularly hazardous, whereas others only have minor poisons.

Frog

• Lizard

Classification

 Phylum - Chordata

 Class - Reptilia

Diagnostic Features

• Lizards have a flexible head, paired male copulatory organs, and scales.

• Although some lizards lack legs, most lizards have a somewhat cylindrical shape, four well-developed legs, a tail that is slightly longer than the head and body put together, and flexible lower eyelids. 

• Their sizes range from one inch.

Features

• The lizards are four-legged creatures with external ears, movable eyelids, a small neck, and a lengthy tail that they can lose to run away from predators.

• Unlike mammals, lizards don't have ear flaps. Instead, they have audible ear holes that allow them to hear, and their eardrums are close to the skin's surface.

Lizard

• Pigeon

Classification

Phylum - Chordata

Class - Aves

Diagnostic Features

• Birds have short necks, thick bodies, and short, narrow bills.

• The pigeon's eyes are attached to the side.

• An operculum or cere, a patch of exposed, pale, inflated soft skin, appears at the base of the upper beak.

Features

• Pigeons' small, streamlined bodies, which are shaped like boats, are perfectly suited for their life in the air. 

• A pigeon's body is made up of the head, neck, trunk, and tail. 

• The head is the frontmost component of the body and is relatively small, round, and positioned there.

Pigeon

• Rabbit

Classification

Phylum - Chordata

Class - Mammalia

Diagnostic Features

• A rabbit's body is rather thick, and it's back is rounded.

• The trunk bears two pairs(Forelimbs and hindlimbs) of pentadactyl limbs. Both pairs of limbs take part in locomotion and support the weight of the body.

Features

• Small, fuzzy creatures, rabbits have huge, powerful hind legs and long ears. They also have short, fluffy tails. They possess two sets of pointed incisors (front teeth).

• Behind the top incisors, they additionally have two peg teeth. Their teeth are designed exclusively for chewing and continue to erupt throughout their entire lifespan.

• Depending on the breed, rabbit weight ranges from 3 to 20 pounds.

Rabbit

Result:

Thus the specimens are identified and their characteristics are noted.

Precautions:

• Do not tilt the jar in which model is kept.

• Do not touch the slide in the middle ,then the slide will not be clear.

• Handle the microscope and the slide carefully.

• Do not write on the specimens.

Lab Manual Questions

1. What are the important differences between workers,queens and drones in honey bees?

Ans: drone- It is a male honey bee.they have big eyes.

Workers- They are female honey bees.

Queen- Body size is larger.it is the mother bee.

2. Mention differences between male and female roundworms?

Ans: male roundworm is shorter while female roundworm is larger.male appear hooked tail while female have straight tail.

3. Is the shell of the snail plain or spirally coiled?

Ans: Snail shells are spiral shaped.

3. How many arms do starfish have?

Ans: Starfish have five arms but some species have a large number of arms.

Viva Questions

1. How many regions can you divide the lizard body?

Ans: Lizard body has four parts-the head,neck,trunk,tail.

2. How is a pigeon’s beak?

Ans: Pigeons have cone ,short beaks.

3. Why is pigeon placed in phylum chordata?

Ans: Pigeon is placed in phylum chordata as it is bilaterally symmetrical(while cutting the body both sides are identical),nerve cord.

4. Where is the mouth located in rohu?

Ans: Mouth is bounded by lips. It is located at the end of the head region.

5. Why is the specimen called starfish?

Ans: Starfish are orange in colour. It is star shaped.

6. Mention the class of Pila.Give one reason.

Ans: Pila is soft and they have a true body cavity.

7. What is the colour of an earthworm?

Ans: Earthworms are deep brown in colour.

8. What is the tail made up of in pigeons?

Ans: It contains a shaft and feathers.

9. Why are lizards grouped in class Reptilia?

Ans: lizards are grouped in class reptilia as they are ectothermic (taking heat from the sun).

10. How long does a honey bee live?

Ans: A honey bee lives for eight weeks to five years.

Practical Based Questions

1. This is not the locomotory organ of protozoans

A.Flagella

B.Cilia

C.Parapodia

D.Pseudopodia

Answer: C.Parapodia

2. When touched with needle ,Amoeba will

A.Split instantly

B.Die

C.Move away

D.Develop pseudopodia

Answer: C.Move away

3.Hydra is placed under the phylum cnidaria as it has

A.Cnidoblasts

B.Tentacles

C.Hypostome

D.Interstitial cells

Answer: A.Cnidoblasts

4.The exterior of Ascaris is covered by

A.Pellicle

B.Epidermis

C.Sclerites

D.Cuticle

Answer: D.Cuticle

5. Haemoglobin is dissolved in plasma in

A.Earthworm

B.Ascaris

C.Tapeworm

D.Insects

Answer: A.Earthworm

6. The process of rearing a silkworm for silk is known as

A.Agriculture

B.Pisciculture

C.Sericulture

D.None of the above

Answer: C.Sericulture

7.Amongst honey bees,the workers are

A.Female

B.Male

C.Both females and males

D.Hermaphrodite

Answer: A.Female

8. The snail has a power of

 A. self-contracting
B. self-collecting
C. self-revealing
D. self-expressing

Answer: B.Self collecting

9. Water vascular system (ambulacral system) is typically found in

A.Hydra

B.Sponge

C.Earthworm

D.Star fish

Answer: D.Starfish

10. A student was given a specimen to identify on the basis of the characteristics given below.

1.They are metamerically segmented.

2.Presence of closed circulatory system.

3.They have circular and longitudinal muscles for locomotion.

Identify the specimen.

A.Frog

B.Pheretima

C.Cockroach

D.Rabbit

Answer: B.Pheretima

Summary

The identification of specimens /slides/models are done through their features .Animals and microscopic organisms are different in their appearance and functions.