New ! Biology MCQ Practise Tests

12th Standard Biology English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Five

12th Standard

    Reg.No. :
  •  
  •  
  •  
  •  
  •  
  •  

Biology

Time : 00:25:00 Hrs
Total Marks : 25
    Answer all the questions
    25 x 1 = 25
  1. ______ is a berry shaped duster of cells.

    (a)

    Blastula

    (b)

    Gastrula

    (c)

    Morula

    (d)

    Zygote

  2. Statement (1): Menstrual cycle occurs once in every 29 days.
    Statement (2): The average age of menopause is 45-50 years.

    (a)

    Statement 1 is correct; statement 2 is incorrect

    (b)

    Statement 1 is incorrect; statement 2 is correct

    (c)

    Both the statements 1 and 2 are correct

    (d)

    Both the statements 1 and 2 are incorrect.

  3. Identify the correct statement.

    (a)

    Lactational amenorrhea is a permanent birth control method

    (b)

    Condoms are made of polyethylene glycol and lambskin

    (c)

    LNG -20 is a copper-releasing IUD

    (d)

    Diaphragm covers the cervix there by preventing sperm entry

  4. Which of the following symbol is used in pedigree analysis to represent unspecified sex?

    (a)

    (b)

    (c)

    (d)

  5. How many structural genes are located in lac operon of E.Coli?

    (a)

    4

    (b)

    3

    (c)

    2

    (d)

    1

  6. Assertion (A): Oparin used the term coacervases
    Reason (R): Coacervates are colloidal particles in aqueous environment

    (a)

    Both A and R are incorrect

    (b)

    Both A and R are correct

    (c)

    Both A and R are correct. R explains A.

    (d)

    A is correct R is incorrect

  7. Biofertilizers are not involved in this process

    (a)

    increase water holding capacity of soil

    (b)

    Help to degrade pollutants

    (c)

    Provide nutrients

    (d)

    Improve soil texture

  8. Which body of the Government of India regulates GM research and safety of introducing GM organism for public services?

    (a)

    Bio-safety committee

    (b)

    Indian Council of agricultural research

    (c)

    Genetic engineering approval committee

    (d)

    Research committee on Genetic manipulation

  9. People who have migrated from the planes to an area adjoining Rohtang Pass about six months back

    (a)

    Have more RBC's and their haemoglobin has a lower binding affinity to O2

    (b)

    Are not physically fit to play games like football

    (c)

    Suffer from altitude sickness with symptoms like nausea, fatigue, etc.

    (d)

    Have the usual RBC count but then haemoglobin has very high binding affinity to O2.

  10. Statement 1: Biodiversity is the assemblage of different life form.
    Statement 2: The term biodiversity was introduced by Edward Wilson.

    (a)

    Statement 1 is correct, statement 2 in incorrect

    (b)

    Statement 1 is incorrect, statement 2 in correct

    (c)

    Both the statements are correct

    (d)

    Both the statements are incorrect

  11. In anatropous ovule, the micropyle faces __________________

    (a)

    Right side

    (b)

    Left side

    (c)

    Upward

    (d)

    Downward

  12. In Mendel’s experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?

    (a)

    Only round seeds with green cotyledons

    (b)

    Only wrinkled seeds with yellow cotyledons

    (c)

    Only wrinkled seeds with green cotyledons

    (d)

    Round seeds with yellow cotyledons an wrinkled seeds with yellow cotyledons

  13. Incase of co-dominance, monohybrid F 1 __________ is 1: 2: 1

    (a)

    Genotype ratio

    (b)

    Phenotype ratio

    (c)

    Both genotype & Phenotype ratio

    (d)

    Ratio is wrong

  14. Which of the following sentences are correct?
    1. The offspring exhibit only parental combinations due to incomplete linkage
    2. The linked genes exhibit some crossing over in complete linkage
    3. The separation of two linked genes are possible in incomplete linkage
    4. Crossing over is absent in complete linkage

    (a)

    1 and 2

    (b)

    2 and 3

    (c)

    3 and 4

    (d)

    1 and 4

  15. Which one of the following ploidy is irrelevant to others?

    (a)

    Monosomy

    (b)

    Trisomy

    (c)

    Tetrasomy

    (d)

    Pentasomy

  16. Number of base pairs does pBR 322 plasmid contains ______

    (a)

    322

    (b)

    4322

    (c)

    4361

    (d)

    3264

  17. The time duration for sterilization process by using autoclave is ______ minutes and the temperature is _______

    (a)

    10 to 30 minutes and 125° C

    (b)

    15 to 30 minutes and 121° C

    (c)

    15 to 20 minutes and 125° C

    (d)

    10 to 20 minutes and 121° C

  18. The enzymatic mixture for chemical isolation of protoplast is

    (a)

    0.5% macrozyme, 2% onozuka cellulase, 13% mannitol

    (b)

    1.5% macrozyme, 0.5% onozuka cellulase, 12% sorbitol

    (c)

    2% macrozyme, 0.5% onozuka cellulase, 13% sorbitol

    (d)

    0.1% macrozyme, 2% onozuka cellulase, 15% mannitol

  19. Match the following and choose the correct combination from the options given below:

    Column I (Interaction) Column II (Examples)
    I. Mutualism
    II. Commensalism
    III. Parasitism
    IV. Predation
    V. Amensalism
    i) Trichoderma and Penicillium
    ii) Balanophora, Orobanche
    iii) Orchids and Ferns
    iv) Lichen and Mycorrhiza
    v) Nepenthes and Diaonaea
    (a)
    I II III IV V
    i ii iii iv v
    (b)
    I II III IV V
    ii iii iv v i
    (c)
    I II III IV V
    iii iv v i ii
    (d)
    I II III IV V
    iv iii ii v i
  20. Assertion (A): Pyramid of energy is upright.
    Reason (R): During the energy transfer at successive trophic levels from producers there will be a gradual decrease

    (a)

    Both A and R are wrong

    (b)

    A is right R is wrong

    (c)

    R explains A

    (d)

    A is right R is not the correct explanation for A

  21. Assertion (A): Ozone acts as a natural sunblock.
    Reason (R): UV rays reaching the earth are deviated from earth.

    (a)

    A is correct R is incorrect.

    (b)

    A is incorrect R is correct.

    (c)

    R explains A.

    (d)

    Both A and R are incorrect.

  22. Tamarindus indica is indigenous to

    (a)

    Tropical African region

    (b)

    South India, Sri Lanka

    (c)

    South America, Greece

    (d)

    India alone

  23. Given below are the plant species and their parts used. Which is the incorrect pair(s)?
    (i) Cajanus cajan : Seeds
    (ii) Anacardium occidentale: nuts
    (iii)Borassusflabellifer: Endosperm
    (iv) Capsicum annum: leaves

    (a)

     i and ii  

    (b)

     ii and iii

    (c)

    iii only

    (d)

     iv only

  24. Choose the wrong option

    (a)

    Lymphocytes are a type of WBC

    (b)

    They form 20-30% of WBC

    (c)

    The B lymphocytes leave the bone marrow before maturity

    (d)

    B Cells can form memory cells.

  25. ______ is a secondary lymphoid organ found in pharynx.

    (a)

    Adenoid

    (b)

    Tonsils

    (c)

    Thymus

    (d)

    Spleen

*****************************************

TN 12th Standard Biology free Online practice tests

Reviews & Comments about 12th Standard Biology English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Five

Write your Comment