BIOLOGY 1 Marks Question

Aortic arch and carotid artery.

The lower part of the curve indicates dissociation of oxygen from haemoglobin while, the upper part of the curve indicates acceptance of oxygen by Hb.

Neural signal from the pneumotaxic centre can reduce the duration of inspiration and thereby alter the respiratory rate.

Functional residual capacity (FRC) refers to the volume of air left in the lungs after a normal expiration.

1. The conducting part transports the air into alveoli.
2. It clears the inspired air from foreign particles.
3. It brings the air to the body temperature.
4. It moistens/ humidifies the air.

During swallowing the glottis is covered by a cartilaginous flap called epiglottis. This prevents entry of food into the respiratory tract.

A cigarette smoker is more likelihood to suffer from emphysema. This will reduce his total lung capacity.

Aortic arch and carotid artery.

Four.

In the foetus, there is a shift to left because foetal haemoglobin has more affinity for oxygen than adult Hb.

Spirometer.

Volume of air remaining in the lungs even after a forcible expiration is called residual volume. This average 1100mL to 1200mL.

Larynx is often called as Adam's apple. It is more prominent in males than females.

Larynx.

Breathing is the process in which animals take in air (oxygen) from their surrounding medium and give out carbon dioxide-rich air into the same medium.

Alveoli are the primary site of exchange of gases in our body.

Because, it has vocal chords to produce sound.

Carbonic anhydrase is an fastest enzyme known so far. It is found in RBC.

Simple diffusion.

The respiratory rhythm is under dual control, i.e., nervous and chemical.

Tidal volume is the volume of air inspired or expired during a normal breath. Its value is approximately 500mL.

The cartilaginous rings.

IC = Tidal volume and inspiratory reserve volume. EC = Tidal volume and expiratory reserve volume.

In alveoli.

3400-4800 mL.

Cigarette smoke contains various harmful chemicals like tar, nicotine, hydrogen cyanide and different metals. They damage alveolar walls due to which respiratory surface in decreased and it causes emphysema. Cigarette smoking is one of the major causes of emphysema. It is a chronic disorder.

Mechanism of respiration varies depending mainly on animal's habitat and level of organisation.

Asthma, emphysema, occupational lung disorders (e.g., silicosis and asbestosis).

During inspiration the po, in alveoli is more than po, in blood capillaries.

1. Aquatic arthropods use special vascularised structures, called gills.
2. Terrestrial arthropods have a branching network of tracheal tubes for breathing.

External respiration and internal respiration are the two phas indirect respiration.Breathing or ventilation is the preliminary phase preceding them.

Asthma is a respiratory disorder which causes difficulty in breathing, wheezing, coughing due to inflammation of bronchi and bronchioles.

The sound producing organ is larynx.

12-16 times per minute in an adult human being.

When the abdominal muscles participate and more volume of air is sent out, it is called forceful expiration.

Gills of fish are richly supplied with blood, to facilitate exchange of gases. Due to this the colour of gills is red.

1. It is called tidal volume.
2. It is about 500ml.

It allows the mammals to eat and breathe at the same time.

Earthworm respires through moist skin. It is called cutaneous respiration.

1. The habitat of the animal.
2. The level of organisation.

Alveoli and their ducts.

It is done with the special instrument called spirometer.

1. Total lung capacity refers to the volume of air accommodated at the end of a forceful inspiration.
2. It is the sum total of:

1. Tidal volume.
2. Inspiratory reserve volume.
3. Expiratory reserve volume.
4. Residual volume.

Medulla and Pons.

Nasal breathing is advisable because it is healthier as the air inhaled gets filtered through the hairs present inside the nose, so cleaner air reaches to the lungs.

Cells continuously need oxygen for the metabolic reactions that releases energy from the moIecules. This energy is used by cells for various functions of body.

During asthmatic attacks there is sudden spasm or contraction of bronchi. This leads to reduced breathing capacity and the person feels a sense of breathlessness.

12-16 times (average 14 times) in a minute.

Pneumonia causes inflammation of the lung alveoli.

Mollusca, Hemichordata, aquatic arthropods.