Biology (Practice Test)

The behaviour of homologous chromosomes during meiosis (their segregation) and independent assortment) and their reunion in fertilisation confirmed that the genetic material occurs in the chromosomes and formed the basis of chromosomal theory of inheritance. Which is propounded independentaly by Sutton and Boveri in 1902. A karyotype composed of two identical sets of dissimilar chromosomes is called diploid set and of single set of chromosomes is called haploid set.

Neutrophils, macrophages, lymphocytes, eosinophils and basophils are the kinds of WBCs which take part in immune system. 

Autecology is the study of individual organism or individual species. It is also known as population ecology.

World AIDS day is organized every year on 1^st December to create the awareness against HIV/AIDS. 

Cancer is characterized by uncontrolled growth and division of cells. Abnormal and persistent cell division localized in a particular region is called benign tumour. Tumour cells may be carried by blood steam or lymph or penetrate directly to other parts of the tissue resulting in dangerous malignant tumour. The spread of cancerous cells to distant sites is termed as metastasis. 

Plasmodium vivax is a digenetic malarial parasite which completes its life cycle on two hosts-mosquito (primary host) and man (secondary host). The life cycle of Plasmodium in mosquito called sporogony and in man schizogony. Schizogony includes three stages of which pre-erythrocytic and exo-erythrocytic schizogony takes place in RBC of blood of man which characterized by the formation of signet ring stage and schizont. 

Filaiasis or elephantiasis is caused in man by a blood and lymph nematode parasite Wuchereria transmitted form man to man by female Culex.

Hemophilia A is caused by a lack of the blood clotting factor VIII; about 9 out of 10 people with hemophilia have type A disease. This is also referred to as classic hemophilia or factor VIII deficiency.

Rabbits and hares belongs to order Lagomorpha of class Mammalia. The zoological name of rabbit is Oryctolagus cuniculus which has a world wide distribution. The North Indian hare is Lepus ruficaudatus while the South Indian hare is Lepus nigricollis. 

Pila globosa (apple snail), Dentalium (tusk shell) and octopus (devil fish) all belongs to phylum Mollusca. 

S. Cerevisiae, <st1:place w:st="on">S. Carlsbeigensis and S. ellipsideus, all microorganisms are used for the manufacture of wine. 'Cider' is a wine from apple juice and has rather low alcoholic content. Wines supply about 75 calories per 100 ml. 

Sea anemone (Metridium) is a cylindrical and radially symmetrical animal which measures 5-7 cm. in length. It is usually brownish or yellowish in colour. Body of sea anemone is divided into oral disc, peadal disc and column. 

In a person, addict for alcohol a part of alcohol is changed to acetaldehyde. Hangover is due to it. Acetaldehyde stimulates formation of fat which is deposited over the wall of arteries and in the cells of liver . With the accumulation of fat the liver cell fail to produce protein and enzymes. There is little regulation of fat, protein and carbohydrate metabolism. This disorder is called fatty liver syndrome. Liver later turns into a fibrous organ. 

Marine teleosts undergoing petrification emit sharp characteristic foul odour, which is due to the production of lactic acid.

Syphilis is a sexually transmitted disease caused by Treponema pallidum. The incubation period of this pathogen varies form 10 to 90 days (average one month). 

In September and October 2001, several cases of anthrax broke out in the United States in the 2001 anthrax attacks, apparently caused deliberately. Letters laced with infectious anthrax were concurrently delivered to news media offices and the U.S Congress, alongside an ambiguously related case in Chile. The letters killed 5.

Laccifer lacca, (=Tachardia lacca) is the commercially cultured lac insect. It is mainly cultured in India and Bangladesh on the host plants such as ber, Zizyphus mauritiana, palas, Butea monosperma and kusum, Schleichera oleosa.

Body cavity of ascaris is called pseudocoel. It is the space between body wall and the alimentary canal which is not lined by mesoderm. 

The fossils of prehuman and ancestral human forms are obtained form widely diverse regions of Africa, Asia and Europe, which indicates that man's center of origin was probably in Asia and <st1:place w:st="on">Africa. More precisely man has originated in central Asia because the number of domesticated animals and plants is maximum in Asia and the oldest known fossils have been obtained from Asia, China, Java and India. Climatic conditions in Asia and nearby places were most conducive for human evolution. 

Archaeopteryx a transitional fossil between birds and reptiles was discovered from the rocks of Jurassic period, about 140 million years ago. It was discovered in a slate quarry, at Langenaltheim, Bavaria (Germany) in 1861, by “Andreas Wagner”. 

Lens divides eye orbit into aqueous humor and vitreous humor.

Bile is secreted by liver and is stored in the gall bladder. In human bile there are two salts sodium taurocholate and sodium glycocholate. Emulsification of fat takes place through tehse bile salts, therefore, the amount of bile will release in proportion to the amount of fat in meal. 

If a colour-blind man is married to a normal woman all sons and daughters will be normal, but all daughters will be carrier.