The following
events occurs during the process of photosynthesis-
(i) Absorption
of light energy by chlorophyll.
(ii) Conversion
of light energy to chemical energy and splitting of water molecules into
hydrogen and oxygen.
(iii) Reduction
of carbon dioxide to carbohydrates
Heterotrophic nutrition involves
the intake of complex material prepared by other organisms.
The pancreas
secretes pancreatic juice which contains enzymes like trypsin for digesting
proteins and lipase for breaking down emulsified fats.
The
carbohydrates which are not used immediately are stored in the form of starch,
which serves as the internal energy reserve to be used as and when required by
the plant. A somewhat similar situation is seen in us where some of the energy
derived from the food we eat is stored in our body in the form of glycogen.
The pancreas
secretes pancreatic juice which contains enzymes like trypsin for digesting
proteins and lipase for breaking down emulsified fats.
During the process of
respiration, complex organic compounds such as glucose are broken down to
provide energy in the form of ATP.
The digested
food is taken up by the walls of the intestine. The inner lining of the small
intestine has numerous finger-like projections called villi which increase the
surface area for absorption.
the first step
is the break-down of glucose, a six-carbon molecule, into a three-carbon
molecule called pyruvate. This process takes place in the cytoplasm.
Breakdown of
pyruvate using oxygen takes place in the mitochondria.
Steps of
Respiration:-
In human beings
(Fig. 6.9), air is taken into the body through the nostrils. The air passing
through the nostrils is filtered by fine hairs that line the passage. The
passage is also lined with mucus which helps in this process. From here, the
air passes through the throat and into the lungs. Rings of cartilage are
present in the throat.
The separation
of the right side and the left side of the heart is useful to keep oxygenated
and deoxygenated blood from mixing.
The force that
blood exerts against the wall of a vessel is called blood pressure. This
pressure is much greater in arteries than in veins. The pressure of blood
inside the artery during ventricular systole (contraction) is called systolic
pressure and pressure in artery during ventricular diastole (relaxation) is
called diastolic pressure. The normal systolic pressure is about 120 mm of Hg
and diastolic pressure is 80 mm of Hg.
Blood pressure
is measured with an instrument called sphygmomanometer. High blood pressure is
also called hypertension and is caused by the constriction of arterioles, which
results in increased resistance to blood flow.
Lymph drains
into lymphatic capillaries from the intercellular spaces, which join to form
large lymph vessels that finally open into larger veins. Lymph carries digested
and absorbed fat from intestine and drains excess fluid from extra cellular
space back into the blood.
Plant transport
systems will move energy stores from leaves and raw materials from roots. These
two pathways are constructed as independently organised conducting tubes. One,
the xylem moves water and minerals obtained from the soil. The other, phloem
transports products of photosynthesis from the leaves where they are
synthesised to other parts of the plant.
In highly differentiated plants,
transport of water, minerals, food and other materials is a function of the
vascular tissue which consists of xylem and phloem.
Next Topic:-Science Class 10 NCERT Textbook- Lesson-7
Next Topic:-Science Class 10 NCERT Textbook- Lesson-7
