Short Test ECOSYSTEM

Ecosystem

Try solving in 20 minutes

1. State the difference between the first trophic levels of detritus food chain and grazing food chain.
2. 8How does primary succession start in water and lead to the climax community? Explain.
3. Why are the pyramids referred to as 'upright' or 'inverted'? Give two examples of inverted pyramids.
4. Why are energy pyramid always erect?
5. Write the equation that helps in deriving the net primary productivity of an ecosystem. Differentiate between primary & secondary productivity.
6. Explain the simplified model of carbon cycle in nature.

Practice Paper: class XII

Lesson Covered:

Strategies for Improvement in Food Production
Microbes in Human Welfare
Biotechnology: Principles & Applications

Time: 1 ½ hour                                                                                                                       MM 40

Instructions:

Q 1-5 (1 mark), 6-10 (2 marks), 11-15 (3 marks), 16-17(5 marks)

1.       Name the first transgenic cow developed and state the improvement in the quality of the product produced by it.

2.       Name the vector used for transferring nematode specific gene in tobacco plant.

3.       What is SCP? Name the organism used for production of SCP.

4.       A resistant variety of Abelmoschus esculentus show resistance against a virus. Name the virus and plant variety.

5.       “A person is suffering with high blood cholesterol.” Which kind of bioactive molecule you will suggest to reduce his cholesterol level?

6.       A banana herb is virus infected. Name the method that will help in obtaining healthy banana plants from this diseases plant.

7.       Name the insect pest killed by the product of cryIAb gene. Explain how this gene makes the plant resistant to the insect pest.

8.       What is activated sludge? Where is it produced? Why is it named so?

9.       What is inbreeding depression. How can it be overcome?

10.   How are sugarcane varieties with high yield, thick stem, high sugar formed that can be grown in North India?

11.   Explain the term MOET. Which hormone is used for this method. Give the key steps of MOET.

12.   What are palindromes? Where are they used?

13.   What was Cohen & Boyer’s contribution to field of Biotechnology? Show diagrammatically.

14.   What is PCR? Where is it used. Represent the key steps diagrammatically.

15.   Draw a well labelled diagram of a cloning vector showing:

Ori, rop, atleast two restriction sites & 2 antibiotic markers. Give function of each.

16.   (a)Write any one drawback of selection of recombinant due to inactivation of antibiotic. Explain how recombinants and non-recombinants are differentiated on the basis of colour production in the presence of a chromogenic substrate?

     (b)Explain why DNA is not able to pass through cell membrane? Which methods are available to make the plant cell competent to take up DNA from surrounding medium?

17.   Given below is the   sketch of one method used to separate DNA fragments:

                

(a) Give the term caption for above diagram.

(b) At which end would be loaded the samples and why?

(c) Analyse the reason for different positions taken up by the DNA bands.

(d)Elaborate the step he would have followed to visualize DNA bands.

(e) Name the gel used in this technique.

VALUE POINTS: CLASS IX MIDTERM

Sequel to previous post.

marking scheme/value points for the sample paper uploaded earlier:

Q.1   A. Lysosome, B. Golgi Complex, C. Plastid / Mitochondria (any 2) ½×1

Q.2  Exosmosis                                                                                            1

Q.3  Conduction & Xylem                                                                           ½×1

Q.4  Striated/Skeletal Muscle                                                                    1

Q.5  In AIDS patients immune system is not working or weakened.    1

Q.6  Mycelium, Large number of spores                                                   ½×1

Q.7  A. Symptoms, b. acute & chronic, c. bacteria, infectious & defieicency ½×6

Q.8  Fungi, to kill bacteria

Q.9  A. Fungi (heterotrophic, cell wall chitin), Plantae (autotrophic, cell wall cytoplasm)              1×3

B. Monocot (single cotyledon, fibrous root, parallel venation), dicot ( 2 cotyledons, tap root, reticulate venation) – any 2           

C. Porifera (cell level of organisation, non motile), Coelentrata (tissue level of organisation, motile)

D. Piesces (aquatic, streamlined body, fins, gills), amphibians (both terrestrial & aquatic, not streamlined body, legs, lungs as well as gills) – any 2

OR

Whittaker’s 5 kingdom classification                                                                                                       3

Q.10                      3 differences between Prokaryotic & eukaryotic cells & diagram of both.                       5

OR

Parenchyma, Collenchyma & Sclerenchyma (2 differences & diagram)

Q.11                      Glycerine – to prevent from drying; Safranin – to stain                                                    1+1

Q.12                      Cockroach (jointed legs, segmented body, chitinous exoskeleton) – (any 2)    1+2

CLASS 9 MIDTERM QUESTION PAPER

Q.1  Name the cell organelle that:                         1/2×2                                                                                                       

a.       Protects cells from infections & toxins.

b.       Synthesizes complex sugars from glucose.  OR

c.       Contains DNA (other than nucleus)

Q.2   While cooking vegetables adding of salt causes the vegetables to release water, thus allowing vegetables to be cooked. Which process is responsible for release of water due to addition of salt?                      1

Q.3   A white flower was kept in red coloured water overnight. By morning the flower turned red. Which process & which tissue is responsible for the red colour of flower?                                                      1

Q.4   An athlete increases his speed as he closes on to the finishing line. Which muscles help him increase his running speed?                                                                                                                                         1

Q.5  Mucor infection in lungs leads to nasal congestion, wheezing throat irritation or coughing in healthy individuals. However, in AIDS patients it can be fatal. Why?                                                                          1

Q.6   2 characteristic behavioural features of fungi are: they are heterotrophic & they are non motile. What special structural characteristics have they developed to                                                                          1/2×2

a.       Obtain food

b.       Ensure survival

Q.7    Fill in the blanks:                                                                                                                                1/2×6

a.       Signs of disease such as fever, vomiting are known as its __________________

b.       Diseases that last for a short period are known as _____________, and those that persist for long periods are known as ________________

c.       Tuberculosis effects our lungs and is caused due to a ___________ while common cold causes cough is caused due to virus.

d.       Diseases caused due to microbes are known as ______________ disease, while diseases caused due to lack of essential nutrients in body are known as __________________ disease.

Q.8  Which organisms are the source of antibiotics? What is their use?                                                    1+1

Q.9  Differentiate (2 differences) between any 3 of the following groups of organisms:                               1×3

a.       Fungi & Plantae

b.       Monocotyledon & Dicotyledon

c.       Porifera & Coelentrata

d.       Pisces & Amphibia

OR

 What is the most popular method of classification of living organisms? Show with the help of flow chart? Name the scientist responsible for this classification.                                                                                  3

Q.10          You are asked to study cells from curd & plant leaf. What differences would you observe in the cells from these two sources (3 differences). Explain with the help of diagrams.                                       5

OR

Tabulate 2 differences between the three types of permanent tissues. Draw diagrams to show each type.

Section B

Q.11          Onion peel cells are kept in glycerine and treated with safranin before viewing under a microscope. Why are glycerine & safranin used?                                                                                                1

Q.12          Identify the organism & give its 2 distinctive features.                                 1+2

MOLECULAR BASIS OF INHERITANCE

In continuation with preparation for Board 2020, let's practise some objective questions from Chapter 6,

 Molecular Basis of Inheritance

These questions will also be very useful for NEET preparation.

OBJECTIVE QUESTIONS

1. The ________________ biomolecule is a characteristic feature of an organism.
2. If the amount of haploid DNA in a human child is 3.3×10⁹bp, the amount of DNA in a normal human adult would be ________________.
3. The _______________ pyrimidine is present in both m RNA & tRNA but not in DNA.
4. The N bases are attached to __ C of deoxyribose sugar while the PO₄ are present on ____ C.
5. The __________________________ technique helped Wilkins & Franklin to study the structure of DNA.
6. The law of complementarity of N bases was given by ______________
7. Stability of double strand of DNA is due to stacking of bases & ____ bonds.
8. Central dogma of molecular biology was given by _________________.
9. The circumference of a sphere is 2.2 m. what would be the number of base pairs of DNA required to encircle the sphere once?
10. The protein involved in packing of DNA of eukaryotes but absent in DNA of prokaryotes is _____________
11. The ‘beads’ in “beads on String” structure is made of ____________, which is further made of __________
12. Euchromatin is active _______________, but heterochromatin is not.

Do not forget to leave comments, queries and doubts. All the Best

HUMAN HEALTH & DISEASES (Class XII)

As per the new CBSE question paper pattern, the proportion of objective questions has been increased substantially. during the Board 2020, it is expected that at least 25% marks would be devoted to 1 mark questions, which will be mostly application based.
So here are some  1 mark questions from Lesson 8 of XII NCERT "Human health & Diseases.
all these questions are strictly from NCERT. so if you are not able to do 5 or more questions; you need to read the lesson again & again.                                                            
👍👍                                   
1-mark questions                

1.      Parasites that cause diseases are known as _________

2.      Mary Mallon was made famous due to her tolerance to a bacterial disease, of which she was a carrier, and hence she was known as ____________.

3.      Cough due to pneumonia can be differentiated from cough due to common cold as in prior ___________ are also affected.

4.      _______________ is the most serious type of malaria, it is caused due to ___________

5.      The initial attack of Plasmodium takes place in _______________ while that of HIV takes place in _________

6.      Primary host of Plasmodium is ________________, & secondary host is _________.

7.      Fertilization of Plasmodium takes place in mosquito’s ___________________

8.      Biocontrol agent used for controlling mosquito larva is _________________.

9.      Besides Dengue, Aedes mosquito are vectors of another viral disease with widespread occurrence in recent years. Name the disease.

10.  _____________________ is the carrier of Entamoeba.

11.  A used comb was placed in the hotel room, which was used by Radha during her stay there. Later that week she felt dry scaly lesions on her scalp & severe itching. What kind of infection could she have acquired?

12.  Write one example of a physiological barrier.

13.  Full forms: PMNL, CMI IgA, MALT, ELISA, NACO

14.  Anamnestic response is due to ____________________ (property) of our immune system.

15.  _________________ immune response is responsible for graft rejection.

16.  A new born child receives antibodies from his mother through _______________ during pregnancy and through ______________ after birth. Both these are examples of ______________ immunity.

17.  Recombinant DNA technology is being used to produce _______________ vaccine using _______________ (name of organism).

18.  _______________ disease has been completely eradicated due to immunization.

19.  _____________ cells are responsible for allergy since they release chemicals like _____________ & _____________. In order to control allergy, doctors recommend _____________ & ____________.

20.  Which enzyme is required for integration of retrovirus genome into human genome?

21.  Is it true that HIV infected cells can survive even when new viruses are being formed and released from it? How does this effect appearance of disease symptoms?

22.  Regulation of cell division in normal mitotic cells is due to ________

23.  ________________ changes benign tumours to malignant tumours.

24.  Both CT & Radiography use X ray? How are the two different?

25.  Neoplastic cells are different from normal cells. This property is used for histopathological studies to detect _______________ (disease)

26.  ______________ are given to activate immune response of AIDS patients.

27.  _______________________ are group of drugs used in doping by sportsperson.

28.  Smack is a depressant obtained from ___________________ of morphine.

29.  Physiological response of body dependent on drugs, when drugs are no more taken __________________

30.  ________________ is caused due to liver damage by alcoholism.

31.  Anabolic steroids are taken by sportspersons to increase ____________, but in women may also lead to ___________________.

32.  Circle the odd one out:

a.       Plague, Diphtheria, Typhoid, Dengue

b.      Rhinovirus, RetroVirus, Bacteriophage, Oncovirus

c.       Amoebiasis, malaria, ascariasis, typhoid

d.      Microsporum, Trichophyton, Epidermophyton, Ringworm

e.      Malaria, Amoebiasis, filariasis, typhoid

f.        Monocytes, Killer T Lymphocyte, B Lymphocyte, Macrophages

g.       Barbiturates, amphetamines, opioids, bezodiazepines

33.  Fill the missing words in following analogy:

         i.            Bacteria : Antibody :: Virus : ________

       ii.            Ascariais: Ascairs :: Pneumonia : ________

     iii.            Cancer : CT Scan :: Typhoid : _________

     iv.            Human : Sporozoites :: Mosquito : _________

       v.            Immunodeficiency : AIDS :: Auto-immune : _________

     vi.            CT: X ray :: MRI :  __________

   vii.            Tonsils : Throat :: Peyer’s Patches : _________________

 viii.            Cannabinoids : Cannabis sativa :: cocaine : _________________

34.  State True/ False

         i.            Hair loss is a common symptom of Cancer.

       ii.            Dopamine is a hormone whose activity is interfered due to cocaine abuse.

     iii.             Antiretroviral drugs can completely cure AIDS.

     iv.            S in AIDS stands for Symptoms

       v.            While dealing with snakebite patients, doctors should choose passive immunity.

     vi.            Memory of our immune system is an asset but specificity a drawback in developing vaccines.

   vii.            The antigen binding site are present at C terminal of antibody molecule.

 viii.            Only female mosquito is responsible for the spread of Wuchereria.

35.  Who am I?

A.      Reservoir of erythrocytes

B.      Formed at secondary lymphoid organs due to proliferation of lymphocytes as they interact with antigens.

C.      reduce in size with age, but am responsible for immune response

D.     A vestigial organ but also a secondary lymphoid organ 

E.      constitute 50% of lymphoid tissue in your body

F.       HIV Factory

G.     Gene responsible for oncogenic transformation of cells 

H.     Source of hallucinogens 

I.        Drugs for Post-surgical care

J.        Alkaloid that stimulates adrenal glands causing rise in BP & heart rate; also an important carcinogen.