Chapter 1

Question 1

What is gaseous exchange?

Answer 1

the exchange of oxygen and carbon dioxide between organisms and the environment. The area where this takes place is called respiratory surface, and it takes place through the process of diffusion.

Question 2

What is the equation for respiration?

Answer 2

C6H12O6+602 = 6CO2 = 6H20 + Energy

Question 3

What do plants use for intercellular respiration?

Answer 3

Stomata, intercellular space, cuticle, and lenticles

Question 4

Role of plant stomata in respiration

Answer 4

Land plants get their oxygen directly from the air which enters through the stomata, which leads to the intercellular space between the spongy mesophyll cells. These mesophyll cells act as the gas exchange surface.

Question 5

role of the cuticle and lenticles in respiration?

Answer 5

Some gaseous exchange occurs in the cuticles in young plant stems. In woody stems and roots, the plant has dead cells beneath the epidermis which constitutes the cork tissue. This cork tissue has pores called lenticles, which also facilitates gases

Question 6

What is diffusion in plants?

Answer 6

Diffusion is the process of movement of molecules from a region of higher concentration to a region of lower concentration. Diffusion in Plants is a very important process for photosynthesis where carbon dioxide from the stomata diffuses into the leaves and into the cells.

Question 7

What is produced via photosynthesis?

Answer 7

Glucose and oxygen which are used in respiration by plants. Surplus glucose is stored as starch of converted into protein or fats, whereas oxygen is given out.

Question 8

What is the air passageway consisted of?

Answer 8

nose, pharynx, larynx, trachea, bronchi, and bronchioles.

Question 9

What do you know about the structure of the nose?

Answer 9

It is an elevated structure divided in two parts. The external part or the nasal entrance are the nostrils which have hairs and the internal part is known as the nasal cavity. The nasal cavity has a lining of nerve cells that is responsible for smelling. Base walls are layered will ciliated epithelial cells, between which there are goblet cells which produce mucus.

Question 10

Function of the nasal cavity

Answer 10

It warms, moistens, and filters thee air entering the air passageway. Nose hairs block large dust particles, the mucus moistens the air while trapping thinner dust and smoke that pass the nose hairs, while the cilia cells sweep trapped particles and mucus towards the pharynx, from where they are either spat out or swallowed. By the time the air reaches the lungs, it is moistened and relatively dust free.

Question 11

Function of the pharynx in respiration?

Answer 11

The channel which air passes on its way to the lungs is called the pharynx, which is at the back of the mouth. There are many openings, one of which is the larynx, through which the air is channelized. larynx is also the voice box and is a cartilaginous structure. It surrounds the upper end of the trachea. The cavity of the larynx is called glottis, which is covered by the cartilaginous Epiglottis.

Question 12

Function of the trachea

Answer 12

Trachea is a tube running from the pharynx to the lungs. It’s held permanently open by C shaped rings of cartilage in its walls. These rings keep it open when it develops low internal pressure during every intake of breath.

It divides into two individual tubes that enter the two individual lungs, these are the bronchi. Each bronchus divides many times to form fine branches called bronchioles. The bronchi also have cartilages that keep them open.

The finer bronchioles divide further into alveolar ducts which end in tiny hollow bags called air sacs. These air sacs have tiny pockets known as alveoli, which are the respiratory surface of a mammal.

Question 13

Function of the lungs

Answer 13

Lungs lie in the thorax on either side of the heart, protected by the ribs and intercostal muscles. Each lung is surrounded by a double membrane called pleura. The space between the two membranes is filled with a fluid that allows them to glide over one another.

Lungs are spongy due to the alveoli, whose grape bundle or bubble-like arrangement gives the lungs a much larger surface area. Each alveolus is surrounded by many capillaries which diffuse oxygen into the blood once the oxygen is moistened by the alveolus’s surface. C02 diffuses in the opposite direction into the alveolus as the oxygen diffuses into the thin-walled capillaries.

Question 14

Detail Inhalation

Answer 14

When we breathe in, air ruches into our lungs to equalize the reduction of air pressure in the thoracic cavity. This happens due to the contraction of the intercostal muscles which lift up the ribs. The diaphragm contracts by lowering it, increasing the volume of the chest cavity. This increase causes the pressure to drop below atp which causes air to rush in.

Question 15

Detail exhalation

Answer 15

Muscles of the ribs and the diaphragm relax, allowing the thoracic cavity to return to its original smaller size. The lungs contract in return to let the air expel.

Question 16

Exercise and Breathing

Answer 16

Normal respiration occurs at the rate of 15 to 20 times per minute under a resting condition. During exercise, more energy is needed which is provided by more and more oxidation of glucose which results in more C02 being produced. For this we need to breathe at a faster rate.

Question 17

How does the mind know when to breathe quickly

Answer 17

The medulla oblongta of the brain has a breathing center. The cells in the breathing center can detect changes in the concentration of Co2 in the blood, which if high, sends the signal through nerves to increase the rate of breathing.

Question 18

What is bronchitis?

Answer 18

Inflammation of the air passages. A symptom is the excessive production of mucus by the goblet cells in response to irritation. This causes repeated coughing, which increases with breathlessness. It can be acute or chronic.

It is the side effect of viral infections like flu, and is commonly caused by smoking and even air pollution. The infection can go away on its own, but relief can be granted by not smoking, resting, drinking lots of fluids, or using medicinal inhalers or antibiotics.

Question 19

Emphysema

Answer 19

Emphysema is the over inflation of alveoli in the lungs, decreasing long function. Inflammation of the bronchioles can also occur.

Symptoms include breathlessness and an inability to walk in extreme cases. Caused by the gradual breakdown of alveoli walls and the total surface area for gaseous exchange. Main cause is long term lung irritation like cigarette smoke, industrial dust, or air pollution.

Damage caused cant be reversed, but quitting smoking is the most effective to avoid further damage. Medications like inhalers can also help.

Question 20

Asthma

Answer 20

common chronic inflammation of airways.

Symptoms include difficulty breathing, an excess production of mucus and increased swelling of the respiratory pathway Whistling sound is caused whenever breathing.

Occurs due to an allergic response to pollen, household dust, a particular food or feathers. Emotional disturbance also induces an attack.

Temporary relief is provided with inhalers and bronchodilators that dilate the airway. Incurable longterm.

Question 21

Lung Cancer

Answer 21

Cells divided rapidly, forming masses of unspecialized cells called tumors. Usually starts in the epithelium of bronchioles then gradually spreads.

Initially, cell walls thicken and callusing is observed in the cells lining the bronchi. Then there is a loss of cilia, after which a tumor with cancerous cells having a typical nucleus appears. Due to metastasis, the cancer spreads. It may spread to block the bronchus, cutting off air supply.

Main causes are tobacco smoke, though air pollution and car exhaust can also increase its chances. The only treatment is to remove the lung or a lobe of it, or to destroy the cancer tumor with radiation.

Question 22

Differentiate between photosynthesis and respiration

Answer 22

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose using carbon dioxide and water.

Respiration is the process by which cells break down glucose (or other molecules) to release energy, which is stored in the form of ATP (adenosine triphosphate).

Question 23

Differentiate between osmosis and diffusion.

Answer 23

Diffusion is the movement of molecules or ions from an area of higher concentration to an area of lower concentration.

Osmosis is a specific type of diffusion involving water molecules. It is the movement of water molecules through a selectively permeable membrane from an area of lower solute concentration (or higher water concentration) to an area of higher solute concentration (or lower water concentration).

Question 24

differentiate between bronchitis and pneumonia

Answer 24

Bronchitis: Inflammation of the bronchi, the large airways in the lungs. It can be acute (short-term) or chronic (long-term)

Pneumonia: Inflammation of the lung tissue, specifically the alveoli (air sacs), caused by an infection. The infection can be bacterial, viral, or fungal. Pneumonia leads to fluid or pus filling the alveoli, making it difficult for oxygen to pass into the bloodstream.

Question 25

Differentiate between pharynx and larynx

Answer 25

The pharynx is a muscular tube that extends from the back of the nose and mouth to the esophagus and the larynx. It is located just behind the nasal and oral cavity.