Structural Organisation in Animals Test 6

Ciliated columnar epithelial cells are rectangular in shape and have between 200 to 300 hair-like protrusions, called as cilia. Cells are interconnected via desmosomes and tight junctions. Ciliated columnar epithelial cells are found mainly in the tracheal and bronchial regions of the pulmonary system and also in the fallopian tubes of the female reproductive system.

The most abundant type of animal tissue connective tissue. It forms blood, bone cartilage, adipose. Lymph etc.

Basophils are a type of WBC that help the in body defense by formation of heparin for preventing thrombosis or blood clotting.

Whales can live in cold water as they have thick coat of blubber. Blubber help in providing insulating coat beneath the skin that prevents loss of heat from the body.

The female reproductive system in Pheretima consists of the following parts, Ovaries: There is a pair of ovary situated at the 13^th segment hanging on septum between 12^th and 13^th segment

A median flexible lobe, acting as tongue (hypopharynx), lies within the cavity enclosed bythe mouth parts.

The columnar epithelium is found in the lining of stomach and intestine and help in secretion and absorption.

In foetus, formation of erythrocytes takes place in liver and spleen. In young and adult red blood cells (erythrocytes) formation occurs in bone marrow.

Erythrocytes are also known as red blood cells that deliver oxygen to and remove carbon dioxide from tissues. Erythrocytes have a limited life span and as they age, their membranes become more fragile leading to a loss of function and swelling. This damage occurs as the fragile cells pass through narrow capillaries, which occurs in the spleen. The life span of the erythrocyte varies from 70-160 days in domestic species. The average lifespan of RBCs in human is 120 days.

The life span of WBC ranges from 6 - 20 days, depending on the type, after which they are destroyed in the lymphatic system. When immature WBCs are first released from the bone marrow into the blood, they are called bands or stabs. The life span of a circulating human neutrophil is about 5.4 days, while the life span of the monocyte is 10 - 20 hours.

Nerve fibres in the CNS can regenerate after injury due to presence of neurilemma. They are the are outermost nucleated cytoplasmic layer of schwann cells that surrounds the axon of theneuron.

In cockroach, anal styles are absent in females.

The nymph of cockroach grows by moulting about 13 times to reach the adult form.

The squamous epithelium is made of a single thin layer of flattened cells with irregular boundaries. They are found in the walls of blood vessels and air sacs of lungs and are involved in functions like forming a diffusion boundary.

Study of organisms at tissues level is called is calledas histology.

The nasal granules in nerve cell are now identified as ribosomes after discovery of electron microscope that highly magnified image for detailed study.

Platelets are little piece of blood cells the help wounds healingand prevent bleeding by forming blood clot. It is formed from the megakaryocytes.

Ans is option D 

Coorect statement will be :- Muscular layer in the body wall of earthworm is made up of outer layer of circular muscles and an inner layer of longitudinal muscles

Blood is a fluid connective tissue containing plasma, red blood cells (RBC), white blood cells (WBC) and platelets.

In all connective tissues except blood, the cells secrete fibres of structural proteins called collagen or elastin.

Tongue is covered by non-keratinized squamous epithelial tissues having taste buds of different kinds in differentregions of tongue.

The iris contains involuntary smooth muscles. Heart wall consistsof cardiac muscles that are involuntary but striated. Abdominal wall contains connective muscles andbiceps of arm contain skeletal muscle fibres.

Some neutriophils in female mammals possess a small spherical lobe attached to theirnucleus by a stalk. This lobe is called barr body.

In a mature worm, segments 14-16 are covered by a prominent dark band of glandular tissue called clitellum.

During aestivation and hibernation gaseous exchange takes place through skin.

Dense irregular connective tissue has fibroblasts and many fibres that are oriented differently. Fibre and fibloblast is compactly packed is the defnition of dense connective tissue. They show regular and irregular pattern. in dense regular connective tissue collagen are present in row in the parallel form.