Make a diagrammatic sketch of human double circulation. Label the three associated organs and any one blood vessel. OR Name the two types of heart valves and mention their functions.

The diagrammatic sketch given below represents a hypothetical chordate. a) If you find any mistake in the labelled parts, copy the diagram and make necessary corrections in the labeling. b) Based on any two labelled parts in the diagram, mention how this phylum differs from nonchordates.

Observe the blood cells and attempt the following question: . Write one function of any two type.

Read the following statements and find out the incorrect statements. a. Each testicular lobule contains one to three highly coiled seminiferous tubules in which sperm are produced b. Each seminiferous tubule is lined on its inside by two types of cells called Leydig cells and Sertoli cells. c. The region outside the seminiferous tubules called interstitial space, contain small blood vessels and male germ cells (spermatogonia) which lead to sperm formation. d. In testis immunologically component cells are also present. e. The seminiferous tubules of the testis open into the rete testis through vasa efferentia.

Human ABO blood groups are controlled by the gene I, which has three alleles I^A , I^B and i .Each person Passeses any two of the three I gene alleles. Make table showing the different combinations of these three alleles that are possible In human.