quiz (test ur self on transport in plants)

instructions-:please do the questions first and then see if ur right frm the answers below.

1.Name the main type of plant tissue which is responsible for the transport of-:
a)water
b)organic compounds
c)mineral salts
2.What is translcation?
b)Name the type of substancesthat are translocated in plants

3.Defferentiate between guttation and transpiration?
b) name two substances that are secreated by plants in guttation?

4.state two simmilarities between evaporation and transpiration?

5.state the function of root hair


ANSWERS

Que 1.)xylem
b.)xylem
c)phloem
Que 2.)this is the transport of organic substances from the photosynthetic surface to the other parts of the plant.
b)amino acids, lipids and mainly sugars that are in form of glucose
Que3.)transpiration is the loss of water thru the stomata in form of water vapour
Que4.)both need heat energy to change water from liquid state to gaseous state
both take place in the surface of the plant
both involve loss of water in form of water vapour
Que5)root hairs absorb water and dissolve mineral salts from the soil into the plant root

The Structural Adaptations of the mammalian heart to its Functions

It is a muscular/ has cardiac muscles; which are myogenic (do not need nervous stimulation) to pump blood.

It is supplied with vagus and sympathetic nerves; which control the rate of heart beat depending on the body requirements.

It has tricuspid and bicuspid valves between atrium and ventricles; which prevent the back flow of blood to the wrong direction

It has semilunar valves at the base of the pulmonary artery and the aorta; which prevent the back flow of the blood into the right and the left ventricles respectively.

The presence of the valve tendons attached to the atria-ventricular walls; to prevent the atria-ventricular valves from turning inside out due to the changes in the pressure in the ventricles.

The heart is supplied with the coronary artery; which supplies food and Oxygen to the cardiac muscles for their pumping action; the coronary vein in the heart draws away metabolic waste materials.

The heart is enclosed with the pericardial membrane; that secretes a fluid which lubricates it reducing the friction on its walls as it pumps. The pericardial membrane is lined with a layer of fat in the inner wall that act as a shock absorber and holds the heart in position and checks over dilation of the heart.

The heart is divided into two by the atria-ventricular septum; that prevents mixing of oxygenated and Deoxygenated blood.

The left ventricle has a thick muscular wall to pump blood at a higher pressure to the distant body tissues.

The Sino-Atria-Node (S.A.N-the pacemaker region) at the base of the right atrium wall initiates a wave of excitation leading to contraction and relaxation of cardiac muscles.

The Atria-Ventricular Node (AVN) in the heart spreads out the wave of excitation throughout the heart.

ALVEOLUS

An alveolus (plural: alveoli, from Latin alveolus, "little cavity") is an anatomical structure that has the form of a hollow cavity. Found in the lung, the pulmonary alveoli are spherical outcroppings of the respiratory bronchioles and are the primary sites of gas exchange with the blood. Alveoli are particular to mammalian lungs. Different structures are in Location

The alveoli are found in the respiratory zone of the lungs, providing a total surface area of about 75 m2[2]. The blood brings carbon dioxide from the rest of the body for release into the alveoli, and the oxygen in the alveoli is taken up by the blood in the alveolar blood vessels, to be transported to all the cells in the body.

Acute respiratory distress syndrome (ARDS) is a severe inflammatory disease of the lung. Usually triggered by other pulmonary pathology, the uncontrolled inflammation leads to impaired gas exchange, alveolar flooding and/or collapse, and systemic inflammatory response syndrome. It usually requires mechanical ventilation in an intensive care unit setting.

Infant respiratory distress syndrome (IRDS) is a syndrome caused by lack of surfactant in the lungs of premature infants.

In asthma, the bronchioles, or the "bottle-necks" into the sac are restricted, causing the amount of air flow into the lungs to be greatly reduced. It can be triggered by irritants in the air, photochemical smog for example, as well as substances that a person is allergic to.

Emphysema is another disease of the lungs, whereby the elastin in the walls of the alveoli is broken down by an imbalance between the production of neutrophil elastase (elevated by cigarette smoke) and alpha-1-antitrypsin (the activity varies due to genetics or reaction of a critical methionine residue with toxins including cigarette smoke). The resulting loss of elasticity in the lungs leads to prolonged times for exhalation, which occurs through passive recoil of the expanded lung. This leads to a smaller volume of gas exchanged per breath.

Chronic bronchitis occurs when an abundance of mucus is produced by the lungs. The production of this substance occurs naturally when the lung tissue is exposed to irritants. In chronic bronchitis, the air passages into the alveoli, the broncholiotes, become clogged with mucus. This causes increased coughing in order to remove the mucus, and is often a result of extended periods of exposure to cigarette smoke.

Cystic fibrosis is a genetic condition caused by the dysfunction of a transmembrane protein responsible for the transport of chloride ions. This causes huge amounts of mucus to clog the bronchiolites, similar to chronic bronchitis. The result is a persistent cough and reduced lung capacity.

Diffuse interstitial fibrosis
Lung cancer is a common form of cancer causing the uncontrolled growth of cells in the lung tissue. Due to the sensitivity of lung tissue, such malignant growth is often hard to treat effectively.
Pneumonia is an infection of the alveoli, which can be caused by both viruses and bacteria. Toxins and fluids are released from the virus, causing the effective surface area of the lungs to be greatly reduced. If this happens to such a degree that the patient cannot draw enough oxygen from his environment, then the victim may need supplemental oxygen.

Cavitary pneumonia is a process in which the alveoli are destroyed and produce a cavity. As the alveoli are destroyed, the surface area for gas exchange to occur becomes reduced. Further changes in blood flow can lead to decline in lung function.
Pulmonary contusion is a bruise of the lung tissue

adaptations of the lungs to gaseous exchange.

Adaptations of the lungs:

.-It has numerous alveoli; that provide large surface area for efficient gaseous exchange.

.- Epithelial lining between the alveoli wall and the blood capillaries is thin to provide a shorter diffusion distance for easy gaseous exchange.

.- The lung is spongy and has numerous that accommodate large volume of gases (oxygen)

.- It is highly supplied with blood capillaries that transport oxygen and carbon dioxide to and from the body tissues respectively.

.-Its epithelial lining is covered by a thin layer of moisture to dissolve oxygen for easy diffusion into the blood solution.

.-The lung is connected to a tree like system of tubes (the trachea, bronchi and bronchioles ); that supply oxygen and remove the carbon dioxide from the lungs.

.-The whole lung is covered with the pleural membrane which is a gas tight thus changes in the pressure within the lungs can occur without external interference.