The course of the blood between the heart and other parts of the body except lungs is called systemic circulation. 

Lymph is a tissue fluid that transports lymphocytes, antibodies, carries digested and absorbed fats from intestine. It drains excess tissue fluid from intercellular spaces back into  but, lymph does not transport RBCs. RBCs are transported by blood.

The circulatory system is a network consisting of blood, blood vessels and the heart. This network supplies tissues in the body with oxygen and other nutrients, transports hormones and removes unnecessary waste products.

The saliva contains an enzyme called salivary amylase which initiates breaking down of starch into maltose. The complete digestion of carbohydrate occurs in small intestine by pancreatic amylase. The activity of both of these enzymes is affected by pH. Salivary amylase requires pH of 6.5 to 7 to function while the enzymes in small intestines require pH around 7.5 for functioning well. 

Humans have double circulation: one is systemic circulation and other is pulmonary circulation. In systemic circulation, oxygenated blood moves from heart to all parts of the body. In pulmonary circulation, deoxygenated blood is pumped by heart to get oxygenated in lungs. All the deoxygenated blood from the body comes to the right atrium and it moves to the right ventricle from there and finally to the lungs carried by pulmonary trunk. From lungs, oxygenated blood enters left atrium to go to left ventricle to be carried by aorta to whole body. So, the correct answer is 'Right atrium$$\rightarrow$$ right ventricle $$\rightarrow$$ left atrium $$\rightarrow$$ left ventricle'

• Amylase is an enzyme that breaks down complex starch molecules into simple sugars. 
• It is found in the saliva, present in the mouth. 
• it is also released by the pancreas. Due to the presence of amylase in the saliva, it is said that the digestion process starts from the mouth itself.
• Bile juice acts on fats. HCl is not an enzyme, it is an acid. 
• Pepsin is an enzyme that helps in the digestion of proteins.

$$\textbf{Correct Option C}$$

$$\textbf{Solution}$$

$$\bullet$$ $$\textbf{Option A}$$ The digestive system is made up of the digestive tract and other organs that help the body break down and absorb food. It is a long, twisting tube that starts at the mouth and goes through the oesophagus, stomach, small intestine, large intestine and anus.

$$\bullet$$ $$\textbf{Option B}$$ The respiratory system is the network of organs and tissues that help you breathe. It includes your airways, lungs and blood vessels. They delivers oxygen to the cells in your body. This system also helps in removing waste gases, including carbon dioxide, from the body when you exhale.

 $$\bullet$$ $$\textbf{Option C}$$  The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.

$$\bullet$$ $$\textbf{Option D}$$ The endocrine system is a complex network of glands and organs. It uses hormones to control and coordinate your body's metabolism, energy level, reproduction, growth and development, and response to injury, stress, and mood. 

$$\bullet$$ $$\textbf{Option E}$$ The nervous system is the part of an animal's body that coordinates its behavior and transmits signals between different body areas. In vertebrates it consists of two main parts, called the central nervous system (CNS) and the peripheral nervous system (PNS). 

So, the correct option is C. 

In the stomach, the enzyme pepsin breaks protein into smaller pieces called polypeptides. For proper functioning of pepsin, acidic pH is necessary. A pH of 2 is optimum for pepsin function. Antacids neutralize the normal stomach acid pH and bring it up to 6 to 7. As pH rises above 4, pepsin activity decreases or stops. That is why when a person takes too much antacid the pH of the stomach may rise to 11, which affects pepsin production severely. Maltase, Lactase, Lipase, and Sucrase are produced in the small intestine and they are active in a pH range from 2 to 6.

The gastric glands of stomach produce gastric juice, which contains pepsinogen, HCl, and mucus. HCl imparts highly acidic pH to stomach which in turn supports conversion of inactive pepsinogen into active pepsin. The proper acidic environment of stomach triggers the opening of one way pyrrolic sphincter which in turn allow the chyme to move into the small intestine for further digestive processes. Thus, the correct answer is option C.

When stomatal pore opens, exchange of gases and release of water vapour is increased. This causes photosynthesis and transpiration to increase.

The part labelled as 1 is a structure of glomerulus. Blood that is about to be filtered enters a glomerulus, which is a tuft of blood capillaries (the smallest of blood vessels). The glomerulus is nestled inside a cup-like sac located at the end of each nephron, called a glomerular capsule. Glomerular capillaries have small pores in their walls, just like a very fine mesh sieve. .The glomerulus, on the other hand, is sandwiched between two arterioles - afferent arterioles deliver blood to the glomerulus, while efferent arterioles carry it away. 

$$\large\textbf{Correct Option: B}$$

Systolic pressure is measured in the arteries when the heart contracts and is 120 mm of Hg in a normal condition.

WBCs are divided into leucocytes and lymphocytes. Lymphocytes are further divided into macrophages and monocytes. These cells help in the engulfment of any foreign particles inhaled or ingested by our body. Lymphocytes are considered as soldier cells of our body. A Large proportion of these cells is found in the lymphatic system wherein the lymph is present. Thus lymph provides immunity. So, the correct answer is option A.

A. Spleen also referred to as the graveyard of RBCs removes worn-out RBCs and fights infections. It is a part of the lymphatic system

Correct Answer: A

Resins and gums are metabolic by-products of plant tissues. They are formed in the specialized structures called passages ducts. Gums are the waste products usually formed due to the disintegration of the plant cellulose.

Among the mentioned organisms, the one that does not follow all the life processes is the virus. It is a type of organism which only shows signs of life when it is living inside another organism. Hence, viruses are an exception to living organisms and the activities performed by living organisms.

Living organisms are made up of different types of cells. These cells form different organs and perform various functions. All living organisms show the following seven main processes namely nutrition, reproduction, respiration, movement, growth, excretion, and sensitivity. 

• There are four chambers in the human heart. 
• There are two anterior chambers, the auricles which are also called the atrium, and two posterior chambers, the ventricles. 
• The auricles are the “receiving chambers” as they receive blood from different body parts. 
• The ventricles, on the other hand, are the “distributing chambers”.
  
• The ventricles are larger chambers and also have thicker muscular walls when compared to the auricles 
  

The product obtained in the anaerobic respiration of yeast is ethanol. This process is known as fermentation. Alcoholic fermentation is carried out by unicellular organisms like yeast. Yeast breaks down pyruvic acid from glucose anaerobically into ethanol and carbon dioxide in the cytoplasm.

Aerobic respiration is the breakdown of glucose in the presence of oxygen and anaerobic respiration is the breakdown of energy in the absence of oxygen.

The root has further extensions which increase the surface area for absorption. Theses extensions are called root hair, which are present in all types of roots.

Lymph is the tissue fluid that circulates in lymphatic vessels. It is similar to blood but without red blood cells. It is not a metabolic harmful product.

• The pancreas helps in digestion by secreting pancreatic juice in the small intestine. 
• However, the pancreas is a gland and is not a part of the alimentary canal.
• The alimentary canal is a muscular tube that extends from mouth to anus and includes the mouth, pharynx, esophagus, stomach, and intestines.

The deoxygenated blood enters the right atrium through the vena cava. This blood passes to the right ventricle which enters the pulmonary artery to supply the blood to the lungs. The oxygenated blood enters the left atrium through the pulmonary veins. This blood passes into the left ventricle which pumps the blood into the aorta. The aorta supplies the blood to the tissues of the body.

The deoxygenated blood is brought from the different parts of the body by the veins which enter the right atrium through the vena cava. This blood passes to the right ventricle which enters the pulmonary artery to carry the blood to the lungs. The blood is oxygenated and then brought back to the heart through the pulmonary vein. The oxygenated blood enters the left atrium through the pulmonary vein. This blood passes into the left ventricle which pumps the blood into the aorta. The aorta supplies the blood to the tissues of the body through arteries.

• Deoxygenated (unpurified) blood comes into the right atrium of the heart through the superior and inferior vena cava which is then passed to the right ventricle and then to the lungs by the pulmonary artery. 
• In the lungs, this blood gets oxygenated (purified) which then goes into the left atrial chamber of the heart from which blood is passed to the aorta and then circulated to the whole body.

The liquid part of the blood is called plasma. It is composed of water, salts, enzymes, antibodies and other proteins. It is straw coloured liquid portion of the blood. It holds the blood corpuscles and acts as a extracellular matrix for the blood cells.

Photosynthesis is the process by which the light energy from the sun is captured by the chlorophyll pigments present on the leaves (mostly leaves, in few plants, stem also contributes in photosynthesis) and is used for the preparation of food. This process requires raw materials like carbon dioxide and water. 

The gall bladder is the small storage organ which is present in lower and upper to the liver. Gall bladder plays an important role in the digestion of food. Bile is produced by the liver and it is temporarily stored in the gall bladder. Bile contains bile acids which are helpful for the digestion and absorption of fats in the small intestine.

Digestion of starch starts from the mouth. The salivary gland in the mouth secretes saliva, which mixes with the food that is chewed. This is because to moisten the food. The saliva in the mouth contains the enzyme called amylase that is the starch-digesting enzyme.

Tooth decay starts with the erosion of tooth enamel and leads to holes in teeth called cavities. The measures to prevent tooth decay are to brush the teeth twice a day, dental floss, skip sugar, rising the mouth after meals.

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Chocolate is one of the most common agents responsible for tooth decay. A higher intake of it is never beneficial for the teeth.

$$\textbf{Option (B):}$$ 

$$\bullet$$ Sweets are another cause of tooth decay. The artificial sugar that is used in most sweets is the reason behind this.

$$\bullet$$ This artificial sugar breaks down in the mouth causing the effect on tooth enamel.

$$\textbf{Option (C):}$$ 

$$\bullet$$ Cold drinks contain some sugar supplements that are called artificial sweeteners.

$$\bullet$$ Such sugar residue was always possible for causing tooth decay when the sugar broke down in the mouth.

$$\textbf{Option (D):}$$ 

$$\bullet$$ All the different food listed here when consumed can cause tooth decay.

$$\bullet$$ The main reason behind this is artificial sweeteners. All of them have artificial sugar that can directly affect the tooth enamel.

Hence, the correct answer is option (D).

• Blood is made up of two parts i.e., fluid and blood cells. 
• The fluid part i.e., plasma contains water salts & protein and the blood cells comprise of RBCs, WBCs, and platelets. 
• The blood cells are suspended in plasma which constitutes 55% of body fluid.
• Hence, the correct answer is C.

In Cardiology, cardio means 'heart' and logy means 'study'. It is a branch of science dealing with the disorders of the heart as well as parts of the circulatory system. 

Transpiration is the loss of water in the form of water vapor from the parts of the plant. This takes with the help of stomata that are mostly present on the lower surface of leaves. Their opening is controlled by specialized cells called guard cells to regulate the water loss. The water is carried to the leaves from the plant parts against gravity in the upward direction. Thus the correct answer is option A.

Transpiration is a commonly observed process in plants. It refers to the release of water in the form of water vapour from the surface of plants. In plants, transpiration occurs through aerial parts of the plants, i.e. leaves, stems, flowers, fruits. Stomata are small openings present on the surface of the leaves and the release of water vapour occurs through them. About 85-90% of transpiration in plants occur through stomata in leaves.

Correct option: C

Explanation:

• Water carrying tubes transport water and minerals within a plant, from the roots, up to the stem and to all parts of the plant. 
• Vascular tissues are divided into three parts:
• Xylem: transports water
• Cambium: forms secondary vascular tissue
• Phloem: transports food
• 
  

Hence, ‘Xylem’ is the correct answer.

Blood and lymph both are connective fluid tissues that carry $$CO_2$$ (blood also carry $$O_2$$ ), hormones, nutrients and waste products. Haemocyanin is not present in the human being. Thus, the correct answer is option C.

The normal daily production of saliva varies between 0.5-1.5 liters. The whole unstimulated saliva flow rate is approximately 0.3-0.4 ml/min. This rate decreases to 0.1 ml/min during sleep and increases to about 4 ml/min during eating, chewing and other stimulating actvities.