BIOLOGY HSSC II
SECTION - A (Marks 17)
Time allowed: 25 Minutes (Revised Syllabus)
NOTE: Section—A is compulsory and comprises pages 1-2. All parts of this section are to be answered on the question paper itself. It should be completed in the first 25 minutes and handed over to the Centre Superintendent. Deleting/overwriting is not allowed. Do not use lead pencil.
Circle the correct option i.e. A / B I C / D Each part carries one mark.

Question#1

• Tidal volume is the air:
  
  (a) Remaining in the lungs after forced expiration
  (b) Exchanged during normal breathing
  (c) Inhaled after normal inspiration
  (d) Forcibly expelled after normal Inspiration
  
  
• Fresh water fish excrete:
  
  (a) Ammonia
  (b) Uric acid
  (c) Urea
  (d) All of these
  
  
• Which of the following item gives its correct total number?
  
  (a) Thoracic vertebrae in humans — 11
  (b) Floating ribs in humans — 4
  (c) Metacarpals in humans — 8
  (d) Facial bones in humans — 12
  
  
• Which of the following is a naturally occurring compound which reduces the sensation of pain and generates the feeling of well-being?
  
  (a) Acetylcholine
  (b) Dopamine
  (c) Endorphins
  (d) Epinephrine
  
  
• Skeletal muscles are controlled by:
  
  (a) Sympathetic nerve
  (b) Parasympthetic nerve
  (c) Somatic nerve
  (d) Autonomic nerve
  
  
• Deficiency of Adrenal cortex hormone results in:
  
  (a) Cushing's disease
  (b) Graves' disease
  (c) Addison's disease
  (d) Cretinism
  
  
• Ovulation in the human female normally takes place during the female reproductive cycle:
  
  (a) At the end of the proliferative phase
  (b) At the beginning of the proliferative phase
  (c) Just before the end of the secretory phase
  (d) At the mid of the secretory phase
  
  
• The blood vessels of the Allantois become:
  
  (a) Heart
  (b) Umbilical Cord
  (c) Placenta
  (d) Retina
  
  
• Which medilian principle will not operate if two genes under study are closed closed together?
  
  (a) Paired unit factors
  (b) Dorminance
  (c) Segregation
  (d) Independent assortment
  
  
• Okazaki fragments are used to elongate:
  
  (a) The leading strand towards the replication fork
  (b) The lagging strand towards the replication fork
  (c) The leading strand away the replication fork
  (d) The lagging strand away the replication fork
  
  
• Acid rain is produced by:
  
  (a)excess NO₂ and SO₂ from burning fossil fuels:
  (b)excess production of NH₃ by industry and coal gas
  (c)excess release of carbonmonoxide by incomplete combusion
  (d)excess formation of CO₂ by combustion and animal respiration
  
  
• Lamarck theory of organic evolution is usually known as:
  
  (a) Natural selection
  (b) Descent with change
  (c) Inheritance of acquired characters
  (d) Differential reproduction
  
  
• TAQ poly merase is used in PCR because of its:
  
  (a) Low thermal stability
  (b) High fidelity
  (c) High speed
  (d) High thermal stability
  
  
• ___________Chromosomes have arms of equal length with the centromere in the middle:
  
  (a) Submetacentric
  (b) Acrocentric
  (c) Telocentric
  (d) Metacentric
  
  
• When An animal learn a response to a particular stimulus after many successful tries it is called:
  
  (a) Classical conditioning
  (b) Instrumental learning
  (c) Insight learning
  (d) Latent learning
  
  
• Transigenic animals are those which are:
  
  (a) Forign RNA inall its cells
  (b) Forign DNA in some of its cell
  (c) Forign DNA in all its cell
  (d) Both A and B
  
  
• Vinegar is obtained from beer with the help of:
  
  (a) Rhizopus
  (b) Acetobacter
  (c) Yeast
  (d) Clostridium

SECTION - B
(Marks 42)

2.Answer any FOURTEEN parts. The answer to each part should not exceed 3 to 4 lines. (14x3=42)

• What is oxyhaeimoglobin? How is ii formed?
• How does negative feedback operate to control body temperature?
• Define Fracture. Differentiate between its common types.
• Draw a diagram of Sarcomere and label its parts.
• In chemical terms, how the neuronal repolarization is achieved?
• Describe the mode of action of Narcotics and their effects on human nervous system Also give examples.
• Write down the functions of the following:
  (a) Chemoreceptors
  (b) Juxtamedullary Nephrons
  (c) Hormone
• How is the blood calcium level regulated by calcitonin and Parathormone?
• FSH and LH get then names from events of the female reproductive cycle but they also function in males. How cc e 1PL'ir functions in females and males similar?
• Define the following terms Enlist their causes and effects:
  (a) Acromegaly
  (b) Cramp
• What is the process of Induction as d relates to vertebrate development? What' is the difference between Primary and Secondary Induction?
• Differentiate between Dominance and Epistasis
•  How do Endocrine disrupting contaminants affect the reproductive abilities of humans?
• What is the function of etylcholinesterase?
  (b) Why is it necessary?
  (c) What is the result of interfering with the function of this enzyme?
• Write three main steps involved in Polypeptide Elongation in translation process of protein synthesis.
• Enlist the major differences between Divergent evolution and Convergent evolution.
• What is instinct? Also give its examples.
• Highlight the role of Microbes in Biological Nitrogen Fixation.
• Outline the steps of DNA sequencing technique.

SECTION-C
(Marks 26)

Attempt any TWO questions. All questions carry equal marks. (2x13=26)
Question#3
(a) Describe various osmoregulatroy adaptations of freshwater and marine animals (06)
(b) How are synovial joints classified? (07)

Question#4
(a) Discuss neurosecretory role of Hypothalamus. (06)
(b) Describe the structure and function of Placenta in humans. (05)
(c) How is blood group distinguished as positive or negative blood group? (02)

Question#6
(a)Describe LAC Operon Model as positive regulation of gene expression. (07)
(b) How is Gene therapy carried out? (03)
(c) Write down causes and symptoms of Alzheimers disease. (03)