(a) State four characteristics of the Cromagnon man.
(b) Explain the basic postulates of Darwinism.
(c) Archaeopteryx is a connecting link between reptiles and birds. Justify the statement by giving two characteristics of each group.
(a) Characteristics of Cromagnon man :
(i) Height - 180 cm3.
(ii) Cranial capacity- 1660 cm3.
(iii) Had narrow, elevated nose.
(iv) Was an intelligent hunter
(b) Basic postulates of Darwinism:
(1) Enormous fertility in living being — All organisms have an amazing fertility and every organism has an innate desire to produce its own progeny for the continuity of race. The productivity of all living organisms is far beyond the ultimate numbers which can possibly survive.
(2) Struggle for existence — Since the number of individuals produced is far more than the number that will ultimately survive, there is an everlasting competition between organisms at all levels of life. Thus there is struggle for existence which may be of following three types :–
(i) Intraspecific struggle: It is the struggle between the members of the same species since their needs are precisely similar.
(ii) Interspecific struggle : It is the struggle between the members of different species living. Every living form depends upon other organisms for its food.
(iii) Extraspecific struggle is t a struggle with the environment.
(3) Variations under nature — No two individuals of a species are exactly similar and they have some differences. These differences are called variations and without variations evolution is not possible. Variations may be of following types:
(i) Meristic and substantive variations
(ii) Continuous and discontinuous variations
(iii) Somatogenic and blastogenic variations
(4) Natural selection — Due to struggle for existence and useful heritable variations, only those individuals survive which are best fitted to new conditions of life. The individuals which survive show high selective value and in the course of time they develop various adaptive modifications to suit the changed conditions of life.
(5) Origin of species — In the course of long periods of life the best fitted individuals survived and became adjusted to the nature. As environment is ever changing, further changes occur and thus new adaptations appear in organisms. The later descendents after several generations become quite distinct from their ancestors. In this way new species appear.
(c) Reptilian Features —
(1) Presence of teeth in jaws.
(2) Long tail with free caudal vertebrae.
Avian Features —
(1) Presence of feathers on body.
(2) Forelimbs modified into wings.
(a) Differentiate between apes and man with respect to the following characteristics: (i) Posture (ii) Cranium (iii) Brow ridges (iv) Locomotion
(a) Persons suffering from G6PD deficiency are resistant to malaria. Explain.
(b) Define:
(i) Genetic Erosion (ii) Bioinsecticides (iii) Antigen (iv) Psychosis
(c) Define Biofortification.
(a) List the activities of Community Health Services.
(b) Give three early diagnostic symptoms of cancer.
(c) Define: (i) Carrying capacity (ii) Implant (iii) Carcinoma
(a) Give four differences between root apex and shoot apex.
(b) Explain the development of the different types of endosperms in angiosperms.
(c) Explain briefly: (i) Capillary water (ii) Osmosis (iii) Aeroponics
(a) Mention one role and one deficiency symptom of the following elements in plant nutrition:
(i) Phosphorus (ii) Iron (iii) Chlorine
(a) What are tropic hormones ? Describe the feedback control of tropic hormones with an example.
(b) Explain the conduction of nerve impulse through a nerve fibre.
(c) Draw a labelled diagram of the T.S. of bone.
