Life Processes - Extras

Question 1

what is dental caries

Answer 1

dental caries or dental decay is the gradual softening of the enamel and dentine.

Question 2

what causes dental caries

Answer 2

It begins
when bacteria acting on sugars produce acids that softens or demineralises the enamel.
Masses of bacterial cells together with food particles stick to the teeth to form dental
plaque. Saliva cannot reach the tooth surface to neutralise the acid as plaque covers
the teeth.

Question 3

how can we prevent dental caries?

Answer 3

Brushing the teeth after eating removes the plaque before the bacteria
produce acids.

Question 4

describe the formation of ATP

Answer 4

The energy released during
the process of respiration is used to make an ATP molecule from ADP and inorganic
phosphate.
ADP+ P ——-> ATP~P= ATP
Endothermic processes in the cell then use this ATP to drive the reactions. When the
terminal phosphate linkage in ATP is broken using water, the energy equivalent to
30.5 kJ/mol is released.

Question 5

what is atp used for

Answer 5

ATP can be used in the cells for the contraction of muscles, protein synthesis,
conduction of nervous impulses and many other activities.

Question 6

what are the effects of tobacco on the human body?

Answer 6

Use of tobacco
most commonly affects the
tongue, lungs, heart and
liver. Smokeless tobacco is
also a major risk factor for
heart attacks, strokes,
pulmonary diseases and
several forms of cancers.
There is a high incidence of
oral cancer in India due to
the chewing of tobacco in
the form of gutkha.

Question 7

how does smoking cause lung canceR?

Answer 7

Lung cancer is one of
common causes of
deaths in the world. The
upper part of respiratory
tract is provided with
small hair -like
structures called cilia.
These cilia help to
remove germs, dust and
other harmful particles
from inhaled air.
Smoking destroys these
hair due to which germs,
dust, smoke and other
harmful chemicals enter
lungs and cause
infection, cough and
even lung cancer

Question 8

define blood pressure

Answer 8

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.

Question 9

define systolic and diastolic pressure

Answer 9

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.

Question 10

what is the optimum blood pressure

Answer 10

The normal
systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg.

Question 11

what is the instrument used to measure bp

Answer 11

Blood pressure is measured with an instrument called sphygmomanometer.

Question 12

what is hypertension

Answer 12

High
blood pressure is also called hypertension and is caused by the constriction of
arterioles, which results in increased resistance to blood flow. It can lead to the rupture
of an artery and internal bleeding.

Question 13

why are kidneys extremely important for survival

Answer 13

Kidneys are vital organs for survival. Several factors like infections, injury or restricted
blood flow to kidneys reduce the activity of kidneys. This leads to accumulation of
poisonous wastes in the body, which can even lead to death. In case of kidney
failure, an artificial kidney can be used.

Question 14

what is an artificial kidney

Answer 14

An artificial kidney is a device to remove
nitrogenous waste products from the blood through dialysis.

Question 15

define dialysis

Answer 15

The process of removing waste products and excess fluid from the body, when the kidneys do not function

Question 16

define hemodialysis

Answer 16

in hemodialysis, blood is pumped out of your body to an artificial kidney machine, and returned to your body by tubes that connect you to the machine.

Question 17

explain the process of hemodialysis

Answer 17

Artificial kidneys contain a number of tubes with a semi-permeable lining, suspended
in a tank filled with dialysing fluid.
This fluid has the same osmotic
pressure as blood, except that it is
devoid of nitrogenous wastes. The
patient’s blood is passed through
these tubes. During this passage,
the waste products from the blood
pass into dialysing fluid by diffusion.
The purified blood is pumped back
into the patient. This is similar to the
function of the kidney, but it is
different since there is no reabsorption involved.

Question 18

what is amount of the initial filtrate ? why is it not the same tht we pass

Answer 18

Normally, in a
healthy adult, the initial filtrate in the
kidneys is about 180 L daily.
However, the volume actually
excreted is only a litre or two a day,
because the remaining filtrate is reabsorbed in the kidney tubules.

Question 19

what is organ donation

Answer 19

Organ donation is a generous act of donating an
organ to a person who suffers from non-function of
organ(s).

Question 20

what are the requirements for organ donation

Answer 20

Donation of an organ may be done by the
consent of the donor and his/her family. Anyone
regardless of age or gender can become an organ
and tissue donor. Organ transplants can save or
transform the life of a person.

Question 21

what is the need for transplation

Answer 21

Transplantation is
required because recipient’s organ has been
damaged or has failed by disease or injury. In organ
transplantation the organ is surgically removed
from one person (organ donor) and transplanted to
another person (the recipient).

Question 22

what are the most common transplantations

Answer 22

Common
transplantations include corneas, kidneys, heart,
liver, pancreas, lungs, intestines and bone marrow.
Most organ and tissue donations occur just after
the donor has died or when the doctor declares a
person brain dead. But some organs such as
kidney, part of a liver, lung, etc., and tissues can be
donated while the donor is alive.