11th Class Biology Chapter 1 Introduction Short Questions Answers

1: Organ is a structure formed by several tissue types performing a special function.

2: Organs are composed of tissues and tissues are composed of cells.

3: Examples: Heart, stomach, eye etc. 

Organelle:

1; Organelle is a subcellular structure performing a specific function.

2: organelles are present within the cells.

3; Examples: Mitochondria, Nucleus, Ribosome etc.

Organ and organ system in animals:

1. Organ formation level is more Complex and defined in animals.
2. Organs are part of the organ system; total functions of one process or phenomenon are performed in this system.
3. Example respiratory system, digestive system etc. 

Organ and organ system in plants:

1. Organ formation level in plants is less Complex in plants.
2. Organ in plants usually does not organized to form an organ system like animals.
3. Examples: root, stem, leaves and reproductive structure.

1. In chemotherapy certain anti-cancer Chemicals are given to the patients at regular intervals.
2. These Chemicals may kill both cancerous as well as normal cells. 
3. In Pakistan, Chemotherapy is used to control cancer. 

Gene therapy

1. In this technique the defective gene is repaired.
2. In it normal gene is isolated and inserted into host through bone marrow
3. In Pakistan gene therapy is not used to control cancer.

Theory is a testified hypothesis which can be falsified.

Due to changing nature of life Biology is full of theories.

Theory may not remain uniform and constant in science.

Example of theory is a cell theory, lamarck and Darwin theory of natural selection etc.

Law:

1. A law is a uniform or constant of nature and it is Virtually and irrefutable theory.
2. Due to  changing nature of life  biology has few laws.
3. A scientific law remains uniform or constant in science. Laws are more general than the theories. 
4. Examples  of the biological laws are Hardy-Weinberg Law and Mendel’s Law of Inheritance.

1. Population is a group of living organisms of the same species found in the same place at the same time.
2. Examples number of rats in a field of rice. Number of students in the biology class and population of humans in a city.
3. Autecology  is the study at population level.

Community:

The population of different species (plants and animal etc) living in the same Habitat form a community.

Examples: forest, Garden, pond etc.

Synecology is study at community level.

The process in which living organisms are used to control harmful organisms by competing or killing it.

It is used to increase food production control of pests/insects.

An aphid that attacks walnut tree is controlled biologically by a wasp that parasitizes this aphid’’.

Some bacteria are used as bio pesticides.

Bioremediation:

The detoxification of harmful Chemicals by means of living organisms is called bioremediation.

It is used to lessen pollution. 

Algae (lichen) reduce pollution of heavy metals by bioabsorption.

It involves  drawing specific conclusion from some general principle assumptions or statements. ( general to the specific).

Example :

If all birds have wings and sparrows are birds then sparrows have wings. 

Inductive reasoning:

It involves drawing a General conclusion from some specific observation or statements.(Specific to the general).

Example:

If sparrows have wings and are birds and we know that Eagles Hawkes spirits and cross are birds then all birds have wings.

Advantages :

This technique is used to test whether certain nutrient is essential for the plant or not.  

Soil is complex medium and we cannot conduct experiments on nutrient requirements of plants by growing them in soil. 

Astronauts may use it for growing vegetables in space. However hydroponic farming is not possible yet.

By this technique food can be stored for long time with damaging its nutritional value. 

The transport of food from one place to another can be made easy.

The life today has come through phyletic lineage or evolving populations of the organisms living in the remote past.

Due to evolutionary process the new species are form and this causes increase in biodiversity.

The community is given awareness about the problem causes and cure.

This is a very effective program for elimination and control of the dangerous disease from the human society.

An observer organizes observation into data form and gives a statement as per experience and background knowledge of the event called hypothesis.

An observer organizes observation into data form and gives a statement as per experience and background knowledge of the event called hypothesis.

A clone is defined as a cell or individual and all its asexually produced offspring. All members of a clone are genetically identical except when a mutation occurs.

It is reasoning from general to the specific. It infers a specific conclusion. It often takes from of an “If ……. then”. It is frequently used to frame the testable hypothesis.

It is marine water

These are lead and chromium.

Gene therapy is the treatment of the defective gene by introducing normal and healthy gene into the body through bone marrow cells.

Its name is hepatitis.

Biologist today have classified and divided all living things into five groups according to their similarities and dissimilarities they cell these groups kingdoms.

Biological method is a systemized way to solve biological problems.

An antibiotic is a substance that kills or slows the growth of micro-organisms.

It is the practice of growing plants without soil.

Immunization helps the protection against a particular disease, so that if body comes in contact with that particular disease, it will be able to fight against it.

An explanation derived by scientists from careful observation and supported by results from experiments and other evidences is called hypothesis.

Law is a constant fact of nature which is virtually irrefutable theory while the theory can be disprove by scientists after greater efforts.

It is the drawing of specific conclusions from some general assumptions.