Q.what is toxicology?Described briefly about the environmental toxicology.
Ans: it is a branch of medical science that deals with the nature, properties, effects and the detection of poisons( Dubois and Geiling 1959). It is , therefore, the science of poisons.
Environmental toxicology: it is an entirely new discipline which came into recognition in the year 1962. It is one of the most important sub-fierlds of toxicology. In recent years it has developed greatly because of-
1) The extension use of industrial chemicals, pesticides and natural resources, 2)more intense utilization of urban, agricultural and recreational space and marine environments and 3) increased awareness of the hazards of chemical to wild life, domestic animals and man. In the past the principal emphasis has heen on human subjects and domestic animals.
Various agricultural chemicals or pesticides are the largest group of poisonous substances that are widely in use today. Pesticidws are of various types. These may be insecticides (killing insects),nematicides (killing nematodes), acaricides (killing mites), rodenticides (killing rodents), herbicides or weedicides (killing herbs and weeds), etc. Of all these pesticides, insecticides are the most numerous and most valuable. Initially insecticides have been developed by screening innumerable compounds that kill the pests. At that time scientists did not consider their properties and the consequences of their use. But now the necessity to usse insecticides hasforced the entomologists to study their properties and hazards they may cause to public.
Two important factors defining environmental toxicology of pesticides are-1) among environmental pollutants pesticides are unique in that they are in minute quantities. 2) their effects are confined exclusively to biological systems.
Q.What is a population? Define population density, population growth rate, death rate, and natality.
Ans: population –it is defined as the collective group of organisms of a particular kind in the community. In other words, a population is all of the organisms of the same species living in a space.
POPULATION DENSITY: The size of a population in relation to a definite unit of space is termed population density. The density of a population depends upon the reproductive rate, birth rate, death rate, etc. The population density may change with the environmental conditions, food supply and many other factors.
Population growth rate: it is the net result of natality, mortality and dispersal from the group.
Growth rate: the rate at which individuals are lost by death is called death rate or mortality rate.
Natality: the rate at which new individuals are added to population by reproduction is called natality rate.
Q. State the causes of increase of human population.
Ans; the followings are the causes for the increase of human population:-
1)protection from nature: man contrructed houses so that he can protect himself from wild animals and natural calamities. Then he formed village towns and cities.
2)Control of diseases: in olden days thousands of people died because of illness. But the development of medical sciences has protected them from such diseases.
3)development of agriculture ; man needs foods for his requirements so he developed the technique to cultivate for producing more food. The animals are also used as food.
4)transport: with the development of transport system, the population is also increased food can can be transported to different parts with the development of transport system.
5)storage condition: foods are not available at all times. If the storage condition is not available, the people will die of starvation . With the better storage conditions, the food could be available at all times.
Q. State the factors responsible for the growth of population.
Ans; 1) decline of child mortality.
2) fall in death rate.
3) average life span increases from 30 years to 50 years.
4) control of various fatal diseases and epidemics.
5) development of medical sciences.
6)better sanitary condition.
Q. What are the consequences of over population?
Ans; over population hampers the development of a country . It also results in various socio-economic disturbances. It leads to number of not only national but also individuals family problems. Some of the consequences are given below-
1)unemployment –more number of people means more jobs. If sufficient number of jobs are not available there will be unemployment.
2)poverty- in a family if the members are more and the income is less, it becomes poor with the addition of every child, the poverty increases.
3)food supply: if the population increases there will be shortage of food supply. Because the production of food does not increase at par.
4)education problem: it becomes difficult for the government to provide education to all. Uneducated children cause problems to the society.
5)hygienic condition: more people in a small area make the hygienic condition bad. If the hygienic condition bad, different diseases and epidemics will break out.
6) housing problem: more people means more houses. It will not be possible on the part of the government to provide houses for every family.
7)pollution: if there are more people , then there will be the problem of pollution.
Q. Describe briefly the various measures to control over population.
Ans: 1) To raise the age of marriage is the most effective means.
2) Evils of large family and advantages of small family be emphasized through book, posters,etc.
3) Methods of family planning should be explained to the people through radio, television, etc.
Q. what is tubectomy?
Ans: it is done in females. It is the process of removing a small segment of oviduct and lying the ends. In this case the ovum does not reach thr female reproductive opening and protiens of egg are dissolved. Such females tend to be obese.
Q. What is vasectomy?
Ans: the surgical removal of a segment of vas deferens from the male reproductive organ is called vasectomy. After this vasectomy the sperms would be present for a period of2 months.
Q. Why it is wrong to blame mothers for having given birth to a girl child?
Ans: during one reproductive cycle of a female, only one ovum is produced. This ovum contains only one x-chromosome. But the male products two types of sperms- one containing x-chromosome and other containing y-chromosome. So, the sex of the child is determined right at the time of fertilization. If a sperm with x-chromosome fuses the ovum, the zygote will develop into a female child. If the sperm with y-chromosome fertilizes the ovum , the zygote will develop into a male child . Therefore it is male who is more responsible for maleness or femaleness and not the female . So , it is wrong to blame the female for giving birth to a girl child.
Q. What is tissue culture?
Ans: it is the isolation of cells, tissue or organs of a plant and growing them in aseptic conditions on suitable medium containing a carbon source (sucrose).,hormones and essential nutrients.
Q. What is electrocardiograph?
Ans: it is an instrument for recording the electrical forces produced by the contraction and relaxation of heart muscles during cardiac cycle. It is put on the chest for recording the cardiac cycle. This technique was first used by EINTHOVEN. This instrument will give vital information about heart beat and the conditions of the heart muscles. Now a days, a more sophisticated instrument provided with multichannel monitors is available. This instrument not only gives the ECG (Electrocardiogram) but also the pressures at various chambers of the heart. It also can give other physiological data.
Q. What is electroencephalograph(EEG)?
Ans: it is the spontaneouselectrical activity of thr brain. It recorded by placing the electrodes on the scalp. It was first recorded ss
