BIOLOGY 4 Marks Questions

Pulse Polio: This is a mass immunization program to eradicate poliomyelitis from India. This program was launched in 1995-96. This program has been undertaken with active cooperation from government agencies, NGOs, UNICEF, and CDC.
Key Objectives of Pulse Polio:
i. Not a single child should be missed.
ii. High level of surveillance.
iii. Reporting of any new case within 14 days.
Polio booths are settled throughout the country to cover all the children below 5 years of age. Volunteers are hired to administer
the polio vaccine.
OPV (Oral Polio Vaccine): OPV is an attenuated vaccine. It is produced by the passage of the virus through non-human cells at a
sub-physiological temperature. This produces spontaneous mutation in the viral genome.
A single vial of OPV usually contains 10-20 doses.
On 27th March 2014, WHO declared India a polio-free nation as no new case was reported in the last 3 years.

i. The chemical name of samck is Diacetylmorphine The consumption of samck is considered as abuse because as it is highly addictive, and being a depressant it slows down body functions.
ii. I. Cannabis sativa, affects the cardiovascular system of the body.
II. Erythroxylum coca/coca plant, interferes with the transport of neurotransmitter dopamine/produces sense of euphoria/increased energy.
III. Papaver somniferum, acts as depressant/slows down body function/ reduces pain/sedative.

A person suffering from ADA deficiency can be cured by various methods which are discusses below:
i. Bone Marrow Transplantation: This procedure requires a suitable donor. An identical twin is supposed to be the best donor as the chances of tissue rejection are very high in bone marrow transplantation.
ii. Enzyme Replacement Therapy: Enzyme replacement therapy is based on administering the missing enzyme to the patient by injection.
iii. Gene Therapy: Gene therapy involves taking out the lymphocytes from the patient's blood. Then are lymphocytes are genetically engineered to add the missing gene. Recombinant lymphocytes are grown in a suitable medium and then administered to the patient. This too is not a permanent cure because lymphocytes have a certain lifespan. The patient needs to be administered lymphocytes after frequent intervals. However, the gene isolated from marrow cells producing ADA is introduced into cells at the early embryonic stage could be a permanent cure for this disease.

The evidence for organic evolution are as follow:
i. Fossils/Paleontology evidence: Fossils of earliest life are scanty and only of prokaryotes mostly. Eukaryotes developed later
оп.
ii. Disparity between fossils: Present-day organisms seem to be related to the fossils of the quaternary period but differ from those of the tertiary period. Fossils of the quaternary period are similarly related to the tertiary period but differ from the ones
of the Cretaceous period. These differences are due to changes in the form, structure, and habits of organisms due to evolution.
iii. Extinct organisms: Lots of organisms existed on earth for some time and then got extinct like dinosaurs, toothed birds, pteridosperms, giant horsetails, ancestors of man, etc. Extinction happened due to many factors. Some of the extinct forms have left their modified descendants (Man, modern-day Horse) while others have perished without leaving any descendants (Pteridosperm, Dinosaurs).
iv. Missing Links: These are transitional or intermediate forms between two groups of organisms which occur only in the fossil state. E.g., Seymouria, a missing link between amphibia and reptilia.
v. Plant vs Animal Fossils: Ancestral animals have left more fossils as compared to plants evidently due to the presence of slow decaying harder structures in their exoskeleton and endoskeleton.

i. Many varieties of finches (black bird) were found on the island (Galapagos island), Originally all birds had seed eating features, Gradually as they moved to other geographical areas, The beak structures changed according to the food available there and many other altered beaks arose. Some becoming insectivorous that eat insect and others remaining vegetarian, Hence the process of evolution starting from a point and radiating to other areas of habitats is called adaptive radiation.
ii. No human evolution is not an example of adoptive radiation it is an example of progressive evolution, parent species of Homosapiens have evolved from Homo habilis and to homo erectus lineage.

Advantage of using GM plants are as follows:
i. GM crops are more tolerant of abiotic stresses; like drought, salinity, high temperature, etc. Thus, GM modified crops can be also grown in areas that are not ideal for cultivation.
ii. GM crops reduce the need for chemical pesticides. This helps in saving many useful insects that otherwise get killed by chemical pesticides. It is important to remember that many insects facilitate pollination in crops.
iii. Mineral usage by the plant is more efficient in the case of GM crops. This prevents the early exhaustion of soil nutrients.
iv. GM crops can have enhanced nutritional value. For example; golden rice is fortified with vitamin A. Similarly; carrot has been fortified with iron. GM crops can be tailor-made to provide alternate resources to industries; such as starch or fuel.