wbsed.gov.in : Higher Secondary Biology Question Model Board of School Education West Bengal
Name of the Board : Board of School Education West Bengal
Name of the Exam : Higher Secondary
Subject : Biology
Document Type : Model Questions
Website : wbsed.gov.in
Download Model/Sample Question Paper :
https://www.pdfquestion.in/uploads/wbsed.gov.in/6938-hs_model_ls3.pdf
Model Question Biology :
Sankari Prasad Bhattacharyay
Ballygunj Govt. High School
Group – ‘A’
Q1. Answer the following questions : (Alternatives are to be noted) 2 x 7 = 14
(a) State two differences between tracheid & trachea.
Related : Board of School Education West Bengal Madhyamik English Questions & Answers Model : www.pdfquestion.in/6936.html
(c) State two differences between Penaeid & Non penaeid Prawn.
(d) Write one symptom each of Flacherie & Muscardine of silkworm.
Ans : 1. Flacherie : (i) The body of the larva becomes soft and black.
2. Muscardiine : (i) The body of the larva becomes stiff and is covered with powdery white material.
(e) State the name of four abnormal composition of urine.
Ans : (i) Blood, (ii) Pus Cells, (iii) Protein (albumin) (iv) Ketone bodies.
OR State the role of skin in excretion.
Ans : (i) The skin excretes water, salts, uric acid etc. through sweat and irreversible respiration.
(ii) The skin excretes waxes, hydrocarbons, cholesterol etc. through sebum. Hence the skin is called accessory excretory organ.
(f) Write the now of four hormones secreted from placenta.
Ans : (1) Human chronic gonadotrophin (HCG) (2) Estrogen (3) Progesterone (4) Placental prolactic.
OR State the one function each of somatostation & Prostaglandin.
Ans : (1) Somatostaion – It inhibits the secretion of insulin and glucagon from the pancreatic islets.
(2) Prostaglandins – Inhibit gastric acid secretion and formation of peptic ulcer.
(g) State two difference between plasma and Serum.
Ans. Plasma Serum
1. Blood cells are present 1. Blood corpuscles are absent
2. Presence of thramboplustin 2. Absence of thromboplastin
Group – B :
Answer the following questions : (Alternative are to be noted) 4 x 11 = 44
(a) Classify Bacteria on the basis of flagella.
Briefly describe the structure of “Bacteriophage”.
Ans. The phage virus is tadpole or sperm shaped consisting of a cosahedral head, narrow neck, long tail and phase plate.
(a) Head : – The head is covered by two layers of protein known as capsid containing several units known as capsomeres. The head is hexagonal within the cavity of which double stranded DNA is present.
(b) Neck : – Very short tube like neck connects the head as tail and the neck is surrounded by a disc like circular structure known as collar.
(c) Tail : – The tube like tail contains a hollow core and the surrounding protein sheath called tail sheath.
(d) Base plate : – The base plate is attached at the end of the tail containing six tail fibres and also pin likes spikes are present at the lower surface of the baseplate arising from the corners of the hexagonal plate.
(b) Define “Infloresence”. Discuss main three types of Inflorescene with example.
Ans :
Definition :- The process of arrangement of flowers on the floral axis of a flowering plant is known as influorescence.
Types of inflorescence :-
1. Cymose :- It is the type of inflorescence in which the growth of the main floral axis is delimited by an optical flower and the flowers are arrange laterally in basipetal succession and the lower flowers are formed later. E.g. Sundew.
2. Racemose :- The inflorescence in which the major inflorescence axis is never delimited by a apical flower i.e. the peduncle has an indefinite growth and the flowers appear in acropetal succession is known as racemose inflorescence.
E.g. Brassica campestris.
3. Special condensed cymose :- The inflorescence is basically a cymose but very difficult to be recognized because of its condensed nature.
As for example – Cyathium is such a special type of inflorescence in which the whole inflorescence is covered by a cup shaped green glandular involuese formed by the fervion of bracts. E.g. Pedilanthus (Rangelita) OR, What type of stipules are found in China Rose (Jaba) and Rose.
(c) What do you mean by “Photoperiodism”? Classify plants on the basis of the length of Photoperiod.
Ans: Definition – The response of a particular flowering plant to the effective day length with respect to flowering is known as photoperiodism. Types
On the basis of the duration of photoperiod, plants can be classified into three major categories as follows
1. Short day plant :- These plants require relatively short day light period (8-10 hours) for flowering. E.g. Tobacco.
2. Long day plant :- These plants require longer day light period (12 hours) for flowering. E.g. – Sugar beet.
3. Day neutral plants :- These plants do not exhibit any sensitivity to light period of flowering. E.g. Tomato.