Category: Biology Second Paper

1. Their bodies are slender, elongated and without paired fins. 13-100 cm long.
2. They look like eel or bine fish.
3. The body is strong in nature and free of scales.
4. They have a notochord and neural tube in their spinal cord.
5. The mouth has suction cups and keratinized (horned) teeth.
6. They have seven pairs of florets.
7. The nasal sac does not open into the oral cavity.
8. Although marine, they come to freshwater to spawn and die within days of hatching.
9. They are known as lampreys.
10. The digestive system does not have a stomach and the intestine has spiral membranes. 11. Excretion occurs. The life cycle of the amocete larvae is as follows.
12. Joint appendages and exoskeleton are absent. There are dorsal fins and caudal fins.
[KEY WORDS TO REMEMBER CHARACTERISTICS: bine, scaleless, chub, keratin, floret, lamprey, amocite]

Examples: Petromyzon (Petromyzon marinus), Lampetra (Lampetra tridentatus).

The word Petromyzontida is formed from the Greek words petros meaning stone and myzon meaning sucking. They are known as lamprey. Lives in seas, estuaries and freshwater. Adheres to dead or decaying matter. The larynx creates a suction pool that pulls the rotten material into the mouth. Adults may suck the blood of live fish. Their number of species is 41.

Fish with ugly nature like Bine fish are called hag fish. Their bodies are slender, long and covered with slippery skin. They belong to the Mixini class. For example – Myxine glutinosa.

The Greek word myxa means slime. They are known as hagfish. The ugly fish is called slime eel. Their number of species is 70.
1. Their bodies are slender, elongated, with slippery glands and without paired fins.
2. They look like eel or bine fish.
3. The spinal cord consists of notochord and fibrous neural tube.
4. Their mouth is marginal and has 4 pairs of gills.
5. They have 5–15 pairs of florets.
6. Their nasal sacs open into the oral cavity.
7. The forebrain forms the brain. Cerebellum absent. There are 10 pairs of carotid nerves.
8. They are known as hagfish.
9. They feed on annelids, molluscs, crustaceans, arthropods or dead fish.
10. The digestive system does not contain a stomach and the intestinal spiral is absent.
11. They are all marine.
12. Their life cycle does not have a larval stage.
13. They are unisexual animals. They are excreted. Eggs are yolky and large.
[KEY WORDS TO REMEMBER CHARACTERISTICS: bine, mouth margin, larynx, larynx, nasal sac, hagfish]

Polysaccharide is formed from the Greek words poly meaning many and saccharin meaning sugar. Carbohydrates that break down or break down into many molecules (more than 10) of monosaccharides are called polysaccharides. Their common symbol is (C6H10O5)n. where 10 ≥ n ≤ 3000|

Properties of polysaccharides
(i) It is a complex sugar.
(ii) Its wet analysis yields numerous monosaccharide molecules.
(iii) It is a large molecule.
(iv) Its molecular weight is more than 10,000 daltons.
(v) It is not sweet in taste.
(vi) It is non-granular and insoluble in water.
(vii) It does not contain aldehyde and ketone groups.
(viii) It is an insoluble sugar.

1. Classification based on work
Polysaccharides are divided into three categories based on function.
(i) Stored polysaccharides: All the carbohydrates that are stored in the body as stored food are called stored polysaccharides. For example, starch, glycogen, inulin, dextin, paramylam, livan etc. Starch is the main stored food in plants and glycogen in animals. Dr. Siddiq Publications
(ii) Structural polysaccharides: Carbohydrates which form the cell walls of plants are called structural polysaccharides. For example, cellulose, hemicellulose, pectic acid, chitin, keratin sulfate etc. Cellulose is the main structural component of the cell wall.
(iii) Complex polysaccharides: Those polysaccharides which are composed of sugars and non-sugars are called complex polysaccharides. Such as mucopolysaccharide, agar, hyaluronic acid, chondroitin sulfate, heparin etc. Dr. Siddiq Publications
2. Structural classification
Polysaccharides are divided into two categories based on structure.
(i) Homopolysaccharides or Homoglycans: Carbohydrates that are composed of monosaccharides of the same type are called homopolysaccharides or homoglycans. For example, starch, cellulose, glycogen, inulin etc.
(ii) Heteropolysaccharides or Heteroglycans: Carbohydrates composed of two or more types of monosaccharides are called heteropolysaccharides or heteroglycans. Such as hemicellulose, mucopolysaccharide, pectin, chitin, agar etc.
3. Unit Based Classification: On the basis of structural unit polysaccharides are of several types-
(i) Glucosan: The polysaccharide formed from glucose is called glucosan.
(ii) Fructosan: The polysaccharide formed by fructose is called fructosan.
(iii) Galactasan: The polysaccharide formed by galactose is called galactasan.
(iv) Hexosan: A polysaccharide composed of six carbon monosaccharides is called hexosan.

On the basis of structural unit polysaccharides are of several types-
(i) Glucosan: The polysaccharide formed from glucose is called glucosan.
(ii) Fructosan: The polysaccharide formed by fructose is called fructosan.
(iii) Galactasan: The polysaccharide formed by galactose is called galactasan.
(iv) Hexosan: A polysaccharide composed of six carbon monosaccharides is called hexosan.

Polysaccharides are divided into two categories based on structure.
(i) Homopolysaccharides or Homoglycans: Carbohydrates that are composed of monosaccharides of the same type are called homopolysaccharides or homoglycans. For example, starch, cellulose, glycogen, inulin etc.
(ii) Heteropolysaccharides or Heteroglycans: Carbohydrates composed of two or more types of monosaccharides are called heteropolysaccharides or heteroglycans. Such as hemicellulose, mucopolysaccharide, pectin, chitin, agar etc.

Polysaccharides are divided into three categories based on function.
(i) Stored polysaccharides: All the carbohydrates that are stored in the body as stored food are called stored polysaccharides. For example, starch, glycogen, inulin, dextin, paramylam, livan etc. Starch is the main stored food in plants and glycogen in animals. Dr. Siddiq Publications
(ii) Structural polysaccharides: Carbohydrates which form the cell walls of plants are called structural polysaccharides. For example, cellulose, hemicellulose, pectic acid, chitin, keratin sulfate etc. Cellulose is the main structural component of the cell wall.
(iii) Complex polysaccharides: Those polysaccharides which are composed of sugars and non-sugars are called complex polysaccharides. Such as mucopolysaccharide, agar, hyaluronic acid, chondroitin sulfate, heparin etc. Dr. Siddiq Publications

(i) It is a complex sugar.
(ii) Its wet analysis yields numerous monosaccharide molecules.
(iii) It is a large molecule.
(iv) Its molecular weight is more than 10,000 daltons.
(v) It is not sweet in taste.
(vi) It is non-granular and insoluble in water.
(vii) It does not contain aldehyde and ketone groups.
(viii) It is an insoluble sugar.

Polysaccharide is formed from the Greek words poly meaning many and saccharin meaning sugar. Carbohydrates that break down or break down into many molecules (more than 10) of monosaccharides are called polysaccharides. Their common symbol is (C6H10O5)n. where 10 ≥ n ≤ 3000.