BIOLOGY 1 Marks Question

Plasma is straw coloured, viscous fluid, slightly alkaline and aqueous solution which constitutes about 55% of the blood.

The cardiac impulse originates in cardiac muscle fibres and is not brought to the heart by any nerve fibres. The origin of cardiac impulse is said to be myogenic.

By counting the number of QRS complexes in an ECG in given period of time.

A fish's heart pumps only deoxygenated blood as it is a two-chambered heart with an atrium and a ventricle. The heart pumps out deoxygenated blood which is oxygenated by the gills and supplied to other body parts, from where deoxygenated blood is returned to the heart.

In this, the blood completes its circulation from right ventricle to the left atria through the lungs.

1. Haemoglobin; it is present in the red blood cells.
2. 12-16g in every 100ml of blood.

1. Mesoderm.
2. Pericardium.

1. Angina.
2. High blood pressure.

1. Atria.
2. Ventricles.

Because serum does not have the coagulation/ clotting factor.

Squamous epithelium.

Atherosclerosis is coronary artery disease (CAD) which results in narrowing of lumen of arteries. It occurs due to deposition of fatty substances specially chloesterol and triglycerides in wall of arteries, which grow to form plaques and reduces the blood flow.

1. Aorta.
2. Interventricular septum.

Since the flow of body fluids can be precisely regulated according to the needs, it is considered advantageous to animals.

Lymphocytes – The leucocytes are agranulocytes and are non motile and non phagocytic. They are responsible for immune responses in the body (B-and T-lymphocytes).

Neutrophils – These are the most abundant WBCs and are granulocytes. They destroy foreign organisms entering the body and thus are phagocytic cells.

1. Thrombokinase.
2. Thrombin.

Due to the presence of haemoglobin.

• Eosnophils resist infections.
• They are also involved in allergic reactions.

It is called so, because blood plasma helps in transportation of biologically important materials for life processes like nutrients, gases, wastes, hormones, etc. within the body, which is very essential for the survival of life.

The heart beat originates from the sinoatrial node (SA node) known as the pace maker of the heart. The SA node is a mass of neuromuscular tissue, which lies in the wall of the right atrium near the opening of the superior vena cava.

Stages of cardiac cycle are joint diastole → atrial systole → ventricular systole.

Pulmonary vein carries oxygenated blood from lungs to the heart. Other veins in the body carry deoxygenated blood, hence pulmonary vein is different from hem.

• Individuals who have Rh-factor or Rh-antigen on the surface of RBCs, are called Rh-positive.
• Individuals who do not have Rh-factor or Rh-antigen on the surface of RBCs, are called Rh-negative.

2. Cockroach.

Superior and inferior vena cava enter the heart whereas aorta leaves the heart.

Contraction of heart muscles brings right and left atria at systole and relaxation of heart muscles brings them at diastole.

Serotonin, Histamine, Heparin.

An elevated ST segment in the ECG of a patient is indicative of acute myocardial infarction (heart attack).

One of the major effect of dengue fever is the low platelet counts. It leads to life threatening condition if left untreated.

By counting the number of QRS complex that occurs in a given time period in an ECG.

Pulmonary artery.

Chordae tendinae are the fibres, which attach the AV valves to the wall of the ventricle.

AB positive means that both A and B antigens are present and Rh factor is also present in the blood of that person.

AB positive means that a person has both A and B antigens and also has Rh factor in his blood.

• Fish heart-pumps only deoxygenated blood.
• It has two chambers, a ventricle and an auricle.

Fibrinogen – It is present in blood plasma and” helps in clotting.

Since persons with blood group ‘AB'can receive blood of any group (A or B or AB or O), they are called universal recipients.

Neutrophils and monocytes.

Joint diastole.

Haemoglobin.

No, mitral valve or bicuspid valve is the type of cardiac valve that guards the opening between left atrium and left ventricle of the heart.

Globulin – It is a plasma protein which helps in defense mechanism.

Amphibians and reptiles (except crocodiles).

The septa (atrioventricular septa) is present between the right auricle-ventricle and the left auricle-ventricle.

Stethoscope.

Hepatic portal system is the vascular connection between the digestive tract and liver. The flow of deoxygenated blood from the digestive organs to the liver before returning to the heart is called hepatic portal circulation.

Because congestion of lungs is a symptom of heart failure, it is also called congestive heart failure.

1. No need to worry.

Explanation:
If haemoglobin count is 17gm per 100mL, then there is no need to get worried as the normal haemoglobin count in human blood should be between 12-17gm/mL.

70-75 number of action potentials can be generated by the SA node in a minute.

Because the wall of the capillaries is not permeable to all plasma proteins.

Calcium.

• Plasma is the fluid matrix of blood.
• It constitutes 55% of the blood.

Blood and lymph.

Purkinje fibres are the impulse conducting fibres which relay the contraction impulses from AV node into the walls of ventricles.

Hepatic portal system brings blood from the alimentary canal, pancreas and spleen to the liver.

Lungs.

Hypophyseal portal vein.

Increased systolic pressure results in hypertension (high blood pressure). The normal blood pressure is 120/ 80mmHg (120- systolic and 80-diastolic pressure). Blood pressure persistently higher than normal, e.g., 140/ 90mmHg (140-systolic pressure) or higher causes hypertension.

Granulocytes and agranulocytes.

Smooth muscle and elastic fibres.

At the origin of pulmonary artery from right ventricle and at the origin of aorta from the left ventricle.

6000-8000 per cubic mm is the normal leucocyte count in human.

WBCs play an important role in immune system. They engulf and destroy foreign materials entering our body and thus help in warding off disease.

The coronary system of blood vessels is meant for circulation of blood in the cardiac musculature.

It may not be able to develop sufficient pressure to pump blood in all distant parts of the body.

The time gap of the passage of action potential from SA node to AV node is significant to provide sufficient time for the relaxation of ventricles. This causes fall in ventricular pressure and closing of semi lunar valves that in turn prevents back flow of blood into ventricles.

AV valve.

1. 0.8 second.
2. 70-75 (average 72).

The QRS complex in an electro-cardiogram (ECG) represents ventricular depolarization, i.e., spread of impulse of contraction from atrio-ventricular node (AVN) to ventricles through Purkinje fibres and Bundle of His. Duration of normal QRS complex is less than 0.10 sec and the enlarged Q and R waves indicate myocardial infarction.

1. Albumins.
2. Globulins.

The person suffering from haemophilia lacks clotting factors in blood and as a result the clotting mechanism is defective. So in case of injury the person is at a risk of blood loss.

It may not be able to develop sufficient pressure to pump blood to all distant parts.

Valves are present in the heart and veins to prevent the backward flow of blood.

It indicates the return of ventricles from excited to normal state (repolarisation).

1. Lymphocytes.
2. Eosinophils.

• Megakaryocytes form thrombocytes.
• They are located in the bone marrow

1. Pulmonary artery.
2. Pulmonary vein.

70-75 (an average of 72).

Since the muscles of sinoatrial node can generate action potentials without any external stimuli, it is called autoexcitable.

Fibrous connective tissues.

The congestion of lungs is a symptom of heart failure. Thus, it is also called congestive heart failure.

Because serum does not have the coagulation/ clotting factor.

Tunica media is thinner in veins than in arteries. Hence veins are thinner than arteries.

Bundle of His are mass of specialised fibres that originates from the AV node.

1. 70ml
2. 5000ml

Since blood group O has both anti-a and anti-b antibodies, no other blood group with any antigen can be accepted by it; only blood group O, which lacks an antigen can be transfused.

It is so, because tunica media of an artery is formed of smooth muscle fibres and elastic fibres.

It is the blood clot or coagulum formed of a network of fibrin in which the dead and damaged formed elements of blood are trapped.

The valves allow flow of blood only in one direction and prevent any backward flow.

When blood pressure is more than normal blood pressure the condition is called hypertension.

Arthropoda and mollusca.

Inability of blood to coagulate due to absence of clotting factors can prolong the bleeding time and thus leads to loss of large amount of blood, which might led to death of the person.

Since blood of 'O'group can be transfused to persons of any blood group, persons with blood group 'O' are called universal donors.

Adrenaline and noradrenaline.

In the early few weeks of embryonic life, primitive nucleated RBCs are produced in the yolk sac. In later embryonic stage, RBCs are mainly produced by the liver and spleen. But from birth onwards, RBCs are produced by bone marrow.

Plasma without the clotting/ coagulation factors, is called serum.

Erythrocytes are red in colour due to the iron containing protein, haemoglobin present in them.

Sponges and coelenterates.

They lack any pigment and are colourless; hence, called white blood cells.

Venous valve.

In case of heavy blood loss the oxygen carrying capacity of body is reduced drastically. Blood being the carrier of oxygen and carbon dioxide is transfused to restore normal metabolic functions of the body.

Plasma without clotting factor is called serum.