Biology Test 277

When the stamens get binded in a bunch or a single bundle, it is called Monoadelphous.
The stamens are binded through the filaments of the anthers.
Stamen is composed of several anthers. And filament is a thread like structure which works as a connecting medium for stamen and thalamus.

Phyllode is a modification of leaf or petiole. It is green in colour and is able to carry out photosynthesis. It is a xerophytic adapation. It reduces the rate of transpiration in xerophytic plants like Opuntia. Thus, the correct answer is 'Petiole.'

The term "pappus" refers to a modification of the calyx, which is the outermost whorl of floral organs that typically protects the developing flower bud. The calyx is usually green and consists of sepals, which are often fused together.

A typical flower with superior ovary and other floral parts inferior is hypogynous. A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts. A superior ovary is found in types of fleshy fruits such as true berries, drupes, etc. A flower with this arrangement is described as hypogynous. 
Therefore, the correct answer is option B.

In a floral diagram, the dot on the top represents the position of the flower on the mother axis. The mother axis refers to the main stem or branch from which the flower emerges. The dot helps to indicate the location and orientation of the flower in relation to the mother axis.

so, the correct answer is B

The respiratory or gas-exchange surface consists of millions of small sacs, or alveoli, lined by a simple squamous epithelium.

This epithelium is exceedingly thin to facilitate the diffusion of oxygen and CO₂. 

The alveolar walls also contain cuboidal surfactant-secreting cells.

Hence, the correct option is A

NCERT Reference: Topic- EXCHANGE OF GASES” of chapter "Breathing and Exchange of Gases" of NCERT 

Graph is plotted between oxygen concentration and percentage saturation of haemoglobin with this curve is called dissociation curve.

Dissociation curve is sigmoid in shape.

Hence, the correct option is D.

NCERT Reference: Topic-  Transport of Oxygen” of chapter "Breathing and Exchange of Gases" of NCERT

The pharynx opens into the larynx by a slit-like aperture called the glottis, which is covered by a cartilaginous flap called the epiglottis.

The epiglottis closes the glottis to prevent the entry of food particles during swallowing.

Hence, the correct option is C.

NCERT Reference: Topic- Human Respiratory System” of chapter "Breathing and Exchange of Gases" of NCERT

Workers in a mill or industrial setting may be at risk of developing occupational respiratory disorders.

These disorders can be caused by exposure to various airborne pollutants, such as dust, fumes, chemicals, and particulate matter, which are commonly found in industrial and manufacturing environments.

In industries, produced dust can’t be cope up by the defense system of human body.

Long and continuous exposure gives rise to inflammation leading to fibrosis and thus leading to severe lung damage.

Hence, the correct option is D

NCERT Reference: Topic -"Respiratory Disorders"  of chapter "Breathing and Exchange of Gases" of NCERT.

The respiratory system helps in the regulation of blood pH, gaseous exchange and also contains receptors of smell, produces vocal sound and filters inspired air.

While the cardiovascular system protects against blood loss by the formation of blood clots.

Hence, the correct option is D

NCERT Reference: Topic- Human Respiratory System” of chapter "Breathing and Exchange of Gases" of NCERT