Digestive System The digestive system in frogs is complete, with a mouth and an anus. It consists of an alimentary canal and associated digestive glands. Salivary glands are absent in frogs. Adult frogs are carnivorous, while the tadpoles are herbivorous. Since frogs are carnivores, the length of intestine is reduced and therefore the alimentary canal … Read more

Frogs belong to Class Amphibia of Phylum Chordata.The most common frog species found in India is Euphlyctis hexadactylus (formerly known as Rana tigrina). Habitat Frogs can live both on land and in water. Some they mainly feed on insects. Some species also live on trees. Most of them are carnivorous. Frogs are poikilotherms or cold-blooded … Read more

Reproductive System The cockroaches are dioecius (unisexual). They have well developed reproductive organs. Male reproductive organ Male reproductive system consists of a pair of testes. They are found on the lateral side of the body along the 4th -6th abdominal segments. A thin tube called vas deferens arises from the testis. Vas deferens opens into … Read more

Digestive System The digestive system is complete with a mouth and an anus. The alimentary canal present in the body cavity is divided into three regions: foregut, midgut and hindgut. Foregut– Pharynx, Oesophagus, Crop and Gizzard The mouth opens into a short tubular pharynx, leading to a narrow tubular passage called oesophagus. This in turn … Read more

Morphology Cockroaches are household pests.  They are usually black or brown bodied. They are also the vectors of several diseases. Habitat Cockroaches are nocturnal omnivores.  They are found in wet and damp places. External appearance Cockroaches are triploblastic and bilaterally symmetrical organisms. They have a dorsoventrally compressed body. The size can range from 1 to 3 inches. The … Read more

Earthworms are hermaphrodites. Testis and ovary are present in the same individual. Male reproductive organ Two pairs of testis are present in the 10th and 11th segments. The vas defferentia from the testis joins the prostatic duct in the 18th segment. Paired Accessory glands at present in the 17th and 19th segments. The prostate gland and the spermatic … Read more

Body wall The body wall of earthworm has an external covering of a thin, flexible cuticle. The cuticle has many perforations, though which epidermal glands release their secretions. The epidermis consists of Columnar cells (supporting cells) Glandular cells (which secrete mucus) Sensory or receptacle cells (receives various types of stimuli) Basal cells (present between columnar … Read more

Earthworm is a reddish brown terrestrial invertebrate. They are commonly known as ‘Friends of Farmers’ since they increases the fertility of soil. The most common Indian earthworms are Lampito mauritii (Syn. Megascolex mauritii), Perioynx excavatus and Metaphire posthuma (Syn. Pheretima posthuma). Habitat It usually occupies the upper moist layers of soil which is rich in decaying organic matter. … Read more

The nervous tissue is composed of densely packed nerve cells commonly known as neurons. The neurons are capable of conducting nerve impulses. The nervous tissue arises from ectoderm of a growing embryo. Neurons There are more than 100 billion neurons in a nervous system. They vary in shape and size. All neurons have 3 main … Read more

The muscle cells are also known as muscle fibres because they are thin, long and cylindrical. They are arranged parallel to each other. The muscle fibres are composed of numerous fine fibrils called myofibrils. The muscular tissue is responsible for locomotion and various types of movements in the body organs. The contraction and relaxation of … Read more