Biology A/L structured Essay Question no.3

Structured Essay Questions 3

                                       

1. A (i) Name the monomer and the type of bond between them in the following polymers.

 

Polymer	Monomer	Type of bond
(a) Polysaccharide
(b) Polypeptide
(c) Polynucleotide

 

(ii) Name two uses of carbon 5 (C₅) sugars in living bodies.

 

(iii) What is the ratio between purine bases and pyrimidine bases in a DNA molecule?

      

 (iv) Name the fibrous protein that is needed to make the cytoskeleton

 

(v) Name two differences between Phaeophyta and Rhodophyta

Phaeophyta	Rhodophyta
(a)
(b)

 

 

 

        

 B. (i) (a) Name the nitrogenous polysaccharide which is common to     

               Fungi and Arthropods. 

       

        (b) What is the monomer of the above polysaccharide?

(ii) What are the main components of the primary cell wall and secondary cell wall of fibers?

 

 (iii) (a) Which field of Biology is based on the modern classification system?  

 

 (iv) Write one difference for each regarding the following structures of Chondrichthyes and Osteichthyes

                               Chondrichthyes                      Osteichthyes

     (a) Caudal fin

     (b) Scales  

 

     (v) Write two functions of tube feet of Echinoderms.

 

C (i) (a) What are the two types of energy that are used by organisms to produce their organic food? 

        (1)

        (2)               

(b) What are the common names given to the organisms that used the above types of energy?

     Common name for users of energy type (1)

      Common name for users of energy type (2)

 (ii) Briefly explain the process of mineralization which is done by microorganisms.

 (iii)  What are the organs which are responsible for the following purposes?

·       Secreting of bile-

·       Storing of bile-

·       The place where the function of bile occurs-

 

(1v)  Explain the function of bile.

  

2. A (i). What occurs in photophosphorylation?

.

 

 (ii) (a) what are the 3 steps that occurred in the Calvin cycle?

 

 (b) What is the type of energy used in the Calvin cycle light-independent reaction) of photosynthesis?

 

(c) What is the compound used in the Calvin cycle to obtain hydrogen?

 

(iii) Asbestosis is a disease found in the respiratory system.

 

 (a) What is the cause of the asbestosis? 

      

    

 (b) Briefly explain how the lung tissues are get destructed by this disease

    

 

B (i.) The ascent of sap is done by bulk flow. What are the causes for adhesion and cohesion which facilitate bulk flow?

 

(ii)  Name the 3 paths of the movement of water and solutes across the root in radial transport.

 

      (a)                         (b)                      (c)

 

 (iii) (a) One of the above paths do not have barriers to selective absorption in itself. Name that path and mention the adaptation done by the plant to block that path.

 

 

(iv) What is the adaptation of the phellem to prevent water loss?

 

 

C (i) Name the parts of the human lymphatic system.

 (ii) Name two functions done by the lymphatic system 

  (a)

  (b).

(iii) What are the veins which open to the left ventricle of the human heart?

       

 (iv) (a) What is the location of the pacemaker (Sinoatrial node) which initiates the heartbeat?

           

 

   (b) What is the type of cells found in the SA node?

            

3. A (i) (a) What are the three functional areas of the cerebral cortex?

 

(b) Which area you wrote above is responsible for the following things.

               1. Reasoning –

               2. Perception of taste-

               3. Movement of limbs-

(ii)  Name two functions of the nerve cord?

       

(iii) Name the structures that help to amplify and transmit the tympanic membrane vibrations to the oval window.

 

 (iv)  What is the location of sensory cells in the inner ear?

 

 

 

B (i) Name three differences between endoskeleton   

         of vertebrate and exoskeleton of arthropods  

        Endoskeleton of vertebrates            exoskeleton of arthropods

1

2

3

 (ii) (a) Name the process protruding from the neural arch of typical lumber vertebrae and write the function of each.

                 Process                                               function

 

(iii) (a)After how many weeks from fertilization, a human embryo can be called a foetus?

 

(b) What is the nature of the foetus after 12 weeks?

 

 (iv) Name two gamete releasing prevention methods of human male and female.

Male :

Female:

 

4. A (i) (a) What are sex-linked characters?

 

 (b) Name two sex-linked diseases in the human population.

 

 (ii)  (a) What is a multiple allele condition?

(b) A man who is heterozygous for blood group A married a woman with blood group O.    What would be the possible blood groups of their children?

 

 (iii) What is the difference between an abortion and a miscarriage?

 

 (a) Abortion: 

 

(b) Miscarriage:

 

                          Structured Essay 3

                                   Answers

1. A (i)

 

Polymer	Monomer	Type of bond
(a)Polysaccharide	monosaccharide	Glyosidic bod
(b)Polypeptide	amino acid	Peptide bod
(c)Polynucleotide	nucleotide	Phosphodiester bond

 

 

(ii)  To make RNA, to make ATP

(iii)  1:1, That is number of Purine bases is equal to the number of pyrimidine bases

 

(iv) Microtubules, microfilaments, intermediate filaments

 

(v) Name two differences between Phaeophyta and Rhodophyta

 

	Phaeophyta	Rhodophyta
(a)	Fucosanthin	Phycocyanin
(b)	flagella present in reproductive cells	Flagella absent in reproductive cells

B.  (i) (a)   Chitin

       (b)  Glucosamine

     (ii)  primary cell wall – cellulose

            Secondary cell wall - lignin

     (iii) (a) Molecular biology

      (iv) 

	Chondrichthyes	osteichthyes
(a) Caudal fin	heterocercle	isocercle
(b) Scales	Placoid / dentine	ganoid / bony

     (v) Respiration , feeding

 C (i) (a) (1)  Light energy

               (2)  Chemical energy               

     

     (b)  (1) Photoautotrophs

               (2) chemoautotrophs

 (ii) Microorganisms like bacteria and fungi growing on dead bodies of animals and plants (organic matter) secrete enzyme and do extracellular digestion. By this way complex insoluble organic matter converted into simple soluble inorganic substances. This is known as decomposition

By this way the mineral ions absorbed by plants go to the soil again. This is a cyclic process  and known as the  cycle of mineralization.

 

(iii)  liver

        gall bladder

        duodenum

 

(1v)  Physical digestion of lipids, emulsification

 2. A (i).

In photophosphorylation, using the energy of sunlight activation of PS II occurs. Then ADP is converted into ATP by binding one more phosphate group to it. In this way, chemical energy is stored in ATP molecules.

  (ii) (a) Carboxylation,

            Reduction,

           Regeneration of carbon dioxide acceptor

  (b)  Chemical energy

  (c)  NADPH⁺

(iii) (a)  Inhaling of asbestos fibers and particles

     (b) Inhaled asbestos fibers and particles pass to the alveoli tissues. Small fibers are ingested by macrophages but large fibers are surrounded by macrophages, protein and iron deposits. The macrophages that have engulfed fibers move out of the alveoli and accumulate around respiratory bronchioles and stimulate the formation of fibrous tissues around them. These will cause the destruction of lung tissues.

 B (i.) Adhesion is present due to the attractions of water molecules to the cellulose molecules of xylem walls.

Cohesion is present due to the attractions among water molecules due to hydrogen bonds.

 (ii)  (a) Apoplastic route '   (b) Symplastic route                 (c) transmembrane route

  (iii) (a) Apoplastic route and casparian stripes found in radial walls and transverse walls of endodermis cells.

 (iv) Presence of suberin which is impermeable to water.

 C (i) Lymph capillaries, lymph vessels, lymph nodes, lymph ducts.

 (ii)  (a) Protection from foreign invasive bodies like bacteria and virus, by giving

             specific and nonspecific immunity

       (b) Absorption of fatty acids end products of lipid digestion.

 

(iii) 4  Pulmonary veins

(iv) (a)  It is located in the myocardium of the right atrium near

             the opening of the Superior Vena cava

  (b) There are specialized cells named cardiomyocytes

 3. A (i) (a) Sensory area

               Association area

               Motor area

   (b) 1. Reasoning – Association area

                  2. Perception of taste- Sensory area

                  3. Movement of limbs- motor area

 (ii)  1. Link the central nervous system to sensory and motor

            neurons and facilitate the impulse propagation towards the  

            brain and away from the brain.

        2. Coordinates and produces reflexes

 (iii). Three ear ossicles namely malleus, incus, stapes

 (iv) Where are sensory cells located in the inner ear?

       In Organ of Corti

 B (i)

   

Endoskeleton of vertebra	Exoskeleton of Arthropods
Mesodermal in origin	Ectodermal in origin
Living tissues	non-living tissues
Bone cells and cartilaginous cells	Epidermis and acellular cuticle secreted by the epidermis make exoskeleton

 

 

 

(ii) (a)

Transverse process	Insertion of muscles
Pair of superior articular process	To articulate with adjacent vertebrae above
Spinous process	Insertion of muscles
Pair of inferior articular process	to articulate with the adjacent vertebrae below

(iii) (a) After 6 weeks

 (b) At this age, all the organ systems are completely developed.

 (iv) Male : Vasectomy

      Female: tubal ligation

 4. A (i) (a) Some of the human characters are coded by the genes located on the sex chromosomes. These genes are called sex-linked genes and characters expressed by them are called sex-inked characters.

(b)      Colourblindness

            Haemophilia 

 (ii)  (a) Sometimes there are three or more alleles present in a single genetic locus. So, there are different traits due to the combination of more than two types of alleles. But any diploid individual carries only two such alleles at the equivalent loci of the homologous pair.

 

  (b)  Blood group A heterozygous = I^A I ⁱ     Blood group O = Iⁱ Iⁱ

 

                                          I^A I ^{i                    x}                  Iⁱ Iⁱ

Gametes                    I^A             I ⁱ                          Iⁱ                   Iⁱ

Fertilization        I^A I ⁱ            I^A I ⁱ                  Iⁱ  Iⁱ                     Iⁱ Iⁱ

Genotype            I^A I ⁱ       :     I^A I ⁱ         :        Iⁱ  Iⁱ        :        Iⁱ Iⁱ

           

Group               A                  A                      O                      O

 

(iii)  (a) Abortion:  Premature termination of progressing pregnancy is known as abortion. This uses medicine or surgery to remove the embryo or foetus and placenta from the uterus.

(b) Miscarriage: Natural removal of embryo or foetus from the uterus is called as miscarriage.