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.