15 extra multiple-choice questions for Transportation in Plants and Circulation in Animals (10th Standard Science, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
What is the process of exudation of water droplets from leaves through specialized pores called hydathodes known as?
- A. Transpiration
- B. GuttationCorrect
- C. Imbibition
- D. Plasmolysis
Explanation. Guttation is the loss of excess water in liquid form through specialized structures called hydathodes, usually occurring during humid early mornings due to root pressure.
Q2
In which pathway does water move through the interconnected protoplasts of plant cells via plasmodesmata?
- A. Apoplastic pathway
- B. Symplastic pathwayCorrect
- C. Vascular pathway
- D. Cuticular pathway
Explanation. In the symplastic pathway, water travels from cell to cell by crossing cell membranes and moving through cytoplasmic strands called plasmodesmata.
Q3
What is the main form of carbohydrate transported through phloem tissue from source to sink in plants?
- A. Glucose
- B. Starch
- C. SucroseCorrect
- D. Fructose
Explanation. Glucose synthesized during photosynthesis is converted into sucrose, a non-reducing disaccharide, for transport through phloem sieve tubes.
Q4
Why do mature mammalian red blood cells lack a nucleus and mitochondria?
- A. To increase space for hemoglobin and prevent internal oxygen consumptionCorrect
- B. To allow rapid cell division in circulating blood
- C. To facilitate synthesis of plasma proteins
- D. To store excess glycogen for energy requirements
Explanation. The absence of a nucleus provides maximum internal surface area for hemoglobin, while lacking mitochondria prevents RBCs from consuming the oxygen they transport.
Q5
Which type of white blood cells are the largest in size and exhibit active phagocytic action?
- A. Basophils
- B. Eosinophils
- C. MonocytesCorrect
- D. Lymphocytes
Explanation. Monocytes are the largest agranulocytes, forming about 2 to 8 percent of total leucocytes, and function as scavenger cells through phagocytosis.
Q6
Which heart valve prevents the backflow of blood from the left ventricle into the left atrium during ventricular contraction?
- A. Tricuspid valve
- B. Bicuspid valveCorrect
- C. Pulmonary semilunar valve
- D. Aortic semilunar valve
Explanation. The bicuspid or mitral valve located between the left atrium and left ventricle prevents blood from flowing backward into the atrium during systole.
Q7
In which year and by whom was the Rh factor first discovered in the Rhesus monkey?
- A. Karl Landsteiner and Alexander Wiener in 1940Correct
- B. William Harvey in 1628
- C. Stephen Hales in 1733
- D. Alexander Fleming in 1928
Explanation. The Rh factor was discovered by Karl Landsteiner and Alexander Wiener in 1940 on the red blood cells of the Rhesus monkey.
Q8
The first heart sound 'Lubb' is produced by which cardiac event?
- A. Opening of the aortic and pulmonary valves
- B. Closure of the tricuspid and bicuspid valvesCorrect
- C. Closure of the semilunar valves
- D. Rapid flow of blood into the ventricles
Explanation. The first heart sound Lubb is longer and louder, produced by the closure of the atrioventricular valves at the beginning of ventricular systole.
Q9
Which blood vessel carries oxygenated blood from the lungs back to the left atrium of the human heart?
- A. Superior vena cava
- B. Pulmonary artery
- C. Pulmonary veinCorrect
- D. Renal artery
Explanation. Unlike other veins that transport deoxygenated blood, pulmonary veins carry freshly oxygenated blood from the lungs into the left atrium of the heart.
Q10
How does the composition of lymph differ primarily from that of blood plasma?
- A. Lymph contains more RBCs and fewer WBCs than plasma
- B. Lymph contains no red blood cells and fewer proteins than plasmaCorrect
- C. Lymph contains a higher concentration of blood platelets
- D. Lymph is a dark red viscous fluid containing fibrinogen only
Explanation. Lymph is a colorless interstitial fluid containing plasma and white blood cells, but it lacks red blood cells, platelets, and large plasma proteins.
Q11
What type of impulse originates natively in the sinoatrial (SA) node to initiate cardiac contraction?
- A. Myogenic impulseCorrect
- B. Neurogenic impulse
- C. Hormonal surge
- D. Mechanical vibration
Explanation. Human heart contraction is myogenic, meaning the heartbeat originates natively in specialized cardiac muscle fibers of the SA node without external nerve stimuli.
Q12
Why is a person with AB blood group considered a universal recipient?
- A. Their RBCs carry no surface antigens A or B
- B. Their blood plasma lacks both anti-A and anti-B antibodiesCorrect
- C. Their blood contains high levels of Rh antibodies
- D. Their blood plasma contains both anti-A and anti-B antibodies
Explanation. Individuals with blood group AB have both A and B antigens on RBCs but no antibodies in plasma, so they do not agglutinate donor RBCs.
Q13
Which instrument is used by medical professionals to measure clinical arterial blood pressure?
- A. Stethoscope
- B. SphygmomanometerCorrect
- C. Electrocardiograph
- D. Haemocytometer
Explanation. A sphygmomanometer is the clinical device used along with a stethoscope to measure systolic and diastolic arterial blood pressure.
Q14
What property describes the mutual attraction between water molecules that helps maintain a continuous water column in xylem vessels?
- A. Adhesion
- B. CohesionCorrect
- C. Imbibition
- D. Plasmolysis
Explanation. Cohesion is the attractive force between similar molecules such as water molecules, which prevents breaking of the water column under transpirational pull.
Q15
An increase in the count of which type of leucocytes occurs during allergic conditions and parasitic infections?
- A. Basophils
- B. Neutrophils
- C. EosinophilsCorrect
- D. Monocytes
Explanation. Eosinophils are granulocytes with bilobed nuclei whose numbers surge during allergic reactions and intestinal parasitic infestations to detoxify harmful toxins.
About these Transportation in Plants and Circulation in Animals questions
These are the Additional multiple-choice questions for Transportation in Plants and Circulation in Animals from the Tamil Nadu State Board (Samacheer Kalvi) 10th Standard Science syllabus. Each question shows the correct option and an original, step-by-step explanation so you understand the method, not just the answer. Use the answer key above to jump to any question, then take the practice test to check yourself under exam-like conditions.
Frequently asked questions
How many MCQs are there in Transportation in Plants and Circulation in Animals?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 10th Standard Science MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Transportation in Plants and Circulation in Animals book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
