Class 10 Life Processes Notes PDF Download CBSE Exam 2022
Class 10 Life Processes Notes download pdf for class x of cbse and state board exam 2021-2022.
- Class 10 Life Processes Notes
- Life Processes Notes Class 10 PDF Download
- Class 10 Life Processes Notes PDF Download CBSE Exam 2022
WHAT ARE LIFE PROCESSES?
The maintenance functions of living organisms must go on even when they are not doing anything particular. Even when we are just sitting in
class, even if we are just asleep, this maintenance job has to go on. The processes which together perform this maintenance job are life processes.
Since these maintenance processes are needed to prevent damage and break-down, energy is needed for them. This energy comes from outside the body of the individual organism.
So there must be a process to transfer a source of energy from outside the body of the organism, which we call food, to the inside, a process we commonly call nutrition.
If the body size of the organisms is to grow, additional raw material will also be needed from outside. Since life on earth depends on carbon- based molecules, most of these food sources are also carbon-based.
Depending on the complexity of these carbon sources, different organisms can then use different kinds of nutritional processes.
The outside sources of energy could be quite varied, since the environment is not under the control of the individual organism.
These sources of energy, therefore, need to be broken down or built up in the body, and must be finally converted to a uniform source of energy that can be used for the various molecular movements needed for maintaining living structures, as well as to the kind of molecules the body needs to grow.
For this, a series of chemical reactions in the body are necessary. Oxidising-reducing reactions are some of the most common chemical means to break-down molecules. For this, many organisms use oxygen sourced from outside the body.
The process of acquiring oxygen from outside the body, and to use it in the process of break-down of food sources for cellular needs, is what we call respiration.
life processes class 10 notes
life processes class 10 notes pdf
BIOLOGY LIFE PROCESSES
Life Processes Class 10 Notes
Air is taken in through the nostrils.
Hairs present in the nostrils prevent the entry of dust particles inside the nose.
Nostrils further continue into the nasal cavity.
Nostrils humidify the air passing through it.
There is a bony plate called the palate, which separates the oral cavity from the nasal cavity.
Nasal cavity opens into the pharynx.
The pharynx is a muscular chamber acting as a common passage for the windpipe or trachea and the
food pipe or oesophagus.
It is connected to the larynx through a slit-like opening called the glottis.
The larynx is also called the voice-box or Adam’s apple.
The larynx connects the pharynx to the trachea.
The trachea shows the presence of cartilaginous rings.
The cartilaginous rings provide flexibility thus, facilitating continuous air flow.
The inner wall of the trachea is lined by a mucous membrane consisting of ciliated columnar
The trachea divides into two branches or tubes called bronchi, one of which enters the right lung and
the other enters the left lung.
The bronchi have cartilaginous rings for distention.
Each bronchus divides into fine secondary bronchi. These bronchi further divide into finer tertiary
bronchi. In the lungs, each bronchus finally divides into finer and smaller branches called bronchioles.
The bronchioles further divide to form smaller terminal bronchioles.
The bronchioles divide repeatedly to form a cluster of tiny air chambers called air sacs or alveoli.
Alveoli have thin and moist walls which enable gaseous diffusion with blood capillaries.
The lungs are a pair of spongy and elastic respiratory organs protected by a bony rib cage.
The base of the lungs rests on the diaphragm.
Each lung is covered by two membranes. The inner membrane is called the inner or visceral pleura
and the outer membrane is called the outer or parietal pleura.
The diaphragm is a curved, musculo-fibrous sheath which separates the thoracic cavity from the
The diaphragm plays a major role during respiration.
The intercostal muscles found between the ribs and the radial muscles of the diaphragm bring about
the breathing movements.
When we breathe in, the ribs are pulled upwards and the diaphragm becomes flat which results in an
increase in the volume of lungs.
When we breathe out, the ribs come back to their normal position, the diaphragm is relaxed, lungs
attain their normal size and air is expelled out of the body through the nostrils.