Short Answer TypeName the causative organism of the disease amoebiasis. List three symptoms of the disease.
Prior to a sports event blood and urine samples of sports-persons are collected for drug tests.
(a) Why is there a need to conduct such tests/
(b) Name the drugs the authorities usually look for.
(c) Write the generic names of two plants from which these drugs are obtained.
(i) Write the scientific names of the two species of filarial worms causing filariasis.
(ii) How do they affect the body of infected person(s)?
(iii) How does the disease spread?
A mature embryo sac in a flowering plant may possess 7-cells, but 8-nuclei. Explain with the help of a diagram only.
Mention the evolutionary significance of the following organisms:
The evolutionary significance of given organisms are as
follows:
(a) Shrews The first mammals. These were long tailed, insectivorous, squirrel-like organisms. They gave rise to primitive primates. For example, leones, tarsiers at the beginning of the Palaeocene era.
(b) Lobefins The first amphibians. Modern day frogs and salamanders have evolved from them.
(c) Homo habilis The first human-like primates, lived in Africa about 2 million years ago. They had brain capacity of 700 cc. Also called handy man as they were first and most skillful tool makers.
(d) Homo erectus They appeared after Homo habilis, 1.7million years ago. They had large brain capacities, i.e. 800-1100 cc and were omnivores.
In an agricultural field, there is a prevalence of the following organisms and crop diseases which are affecting the crop yield badly:
(a) White rust (b) Leaf and stripe rust
(c) Black rot (d) Jussids
Recommend the varieties of crops the farmers should grow to get rid of the existing problem and thus, improve the crop yield.
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