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1. Dried seminal stains from clothing are preserved
- As such
- In 40 % formalin
- In 10% formalin
- In 20% formalin
Answer and Explanation
Answer: (1) As such
Explanation: There is no need to preserve dry seminal stains on the cloth. Moreover, this rule is also applied to the majority of body fluids such as dried blood or urine on the clothes.
2. The smear of the whitish-yellow sticky material showed tadpole-like objects which are suggestive of
- Entamoeba Histolytica
- Seminal stain
- Maggots
- Mycobacterium hyphae
Answer and Explanation
Answer: (2) Seminal stain
3. Which one of the following is not an alternative matrix in forensic drug analysis?
- Hair
- Sweat
- Oral Fluid
- Blood
Answer
Answer: (4) Blood
4. Sperms are stored and matured in one of the following:
- Seminal vesicles
- Epididymis
- Vas deferens
- All of the above
Answer and Explanation
Answer: (2) Epididymis
Explanation: When the sperm leave the testes, they are immature and incapable of fertilizing ova but they become mature when they travel through the epididymis. Moreover, mature sperm are stored in the lower portion, or tail of the epididymis.
5. The following protein markers are found in human sperm :
a. Amylase b. Peptidase A c. Transferrin d. Sperm diaphorase
- a and b
- c and d
- b and d
- a and c
Answer
Answer: (3) b and d
6. Assertion (A): Clothes stained with seminal stains should be dried properly before despatch for forensic analysis.
Reason (R): Drying will facilitate fungal and bacterial growth.
- Both (A) and (R) are true
- Both (A) and (R) are false
- (A) is false, but (R) is true
- (A) is true, but (R) is false
Answer and Explanation
Answer: (4) (A) is true, but (R) is false
Correct Reason: Drying decreases bacterial and fungal infection growth.
7. Assertion (A): The presence of spermatozoa does not confirm that the fluid is seminal fluid.
Reason (R): Because spermatozoa can be present in many body fluids.
- Both A and R are false
- A is true but R is false
- A is false but R is true
- Both A and R are true but R is not the correct explanation of A
Answer and Explanation
Answer: (1) Both A and R are false
Explanation: Spermatozoa is a movable sperm and does not present in any other body fluids. Moreover, it can be analyzed from samples taken up to 10 days.
8. Arrange the examination methods of seminal fluid in the proper sequence of semen.
(i) U.V. examination (ii) Visible examination (iii) Acid phosphatase test (iv) Crystal Test
- (i), (ii), (iii), (iv)
- (ii), (i), (iv), (iii)
- (iv), (ii), (i), (iii)
- (iii), (ii), (i), (iv)
Answer and Explanation
Answer: (2) (ii), (i), (iv), (iii)
Explanation:
-> Visible examination in natural light, if not found
-> UV examination: White color illumination is seen
-> Crystal Test: Presumptive/screening test for semen (not specific for semen). Microcrystalline test capable of detecting
(i) Choline (Florence test): False positive in the case of different body fluids, food and drink substances, cleaning products, and laboratory chemicals. Gives only 70% positive result [check reference (iv)]
(ii) Spermine (Barberio test): yellow needle-shaped only when spermine is present. Only 26% of positive results. [check reference (iv)]
-> Acid phosphatase isoenzyme test: Highly specific test for semen as it depends on the detection of seminal acid phosphatase [SAP] and it doesn’t have to do with infertility of males. So, if the semen discharge where spermatozoa are absent due to oligospermia, azoospermia, and vasectomized individuals they still can be detected with the AP isoenzyme test.
-> The acid phosphatase spot test is less specific than the AP isoenzyme test. And both AP spot and isoenzyme are more specific to crystal tests for sperm.
Reference: (i) Concise Textbook Of Forensic Medicine & Toxicology By Sharma. Pg 35
(ii) Essentials of Forensic Medicine and Toxicology, 1st Edition By Suresh Chand. Pg 425.
(iii) Forensic Science and Law: Investigative Applications in Criminal, Civil and Family Justice. Pg 415.
(iv) On Forensic Identification of Semen and Semen Stains (Source).
9. P30 is found in:
- Urine
- Tears
- Milk
- Seminal fluid
Answer and Explanation
Answer: (4) Seminal fluid
Explanation: P30 is a protein also called Prostate Specific Antigen (PSA) which is used for the detection of seminal stains by forensic investigators.
10. Spermine and choline are constituents of:
- Blood
- Semen
- Saliva
- Fecal matter
Answer and Explanation
Answer: (2) Semen
Explanation: Barberio Test: (Detection of Spermine)
-> Few drops of Berberio’s reagent + spermatic fluid= Crystals of sperm (Needle shaped, rhombic & yellow color).
11. The enzyme glyoxalase is present in
- Blood
- Semen
- Hair
- Both (1) and (2)
Answer and Explanation
Answer: (4) Both (1) and (2)
Explanation:
Glyoxalase enzymes are present both in blood and seminal fluid and carry the detoxification of methylglyoxal and the other reactive aldehydes that are produced during various metabolization processes.
Read More: Forensically Important Enzymes and their sources.
12. Acid phosphatase is ______, secreted by a prostate gland into seminal fluid
- Lipids
- Enzyme
- Carbohydrate
- Antigen
Answer
Answer: (2) Enzyme
13. The stains on the clothes can be identified conclusively as seminal stains by:
- Acid Phosphatase Test
- Barberio’s test
- Spermatozoa
- All of the above
Answer
Answer: (4) All of the above
14.. The presence of spermatozoa in the seminal fluid was communicated in 1679 by:
- Lundquest
- Daubert
- Jessica
- Antonie Van Leeuwenhock
Answer and Explanation
Answer: (4) Antonie Van Leeuwenhock
Explanation: Spermatozoa were first described by Antonie Van Leeuwenhock in the 17 century.
15. The best way to locate and characterize a seminal stain is to perform:
- Acid phosphatase color test
- To carry out DNA typing
- Microscopic test for spermatozoa
- Both (1) and (2)
Answer and Explanation
Answer: (1) Acid phosphatase color test
Explanation: Acid Phosphatase color test is the presumptive test for the seminal stains by imparting a purple coloration.
Note: Jump to the main page of Serology MCQs in Forensic Science.
Question no.8 explanation- AP test is preliminary test not confirmatory test.
AP test (specifically AP isoenzyme test) is highly (more specific than crystals test) specific to semen because it depends on the detection of seminal acid phosphatase [SAP] and it doesn’t have to do with infertility in males. So, if the semen discharge where spermatozoa are absent due to oligospermia (very low sperm count), azoospermia, (complete absent), and vasectomized individuals, they still can be detected with the AP isoenzyme test. And AP spot test is also more specific than both of the microcrystal tests.
Que 8. Crystal test is confirmatory like barberio test and Florence test. That’s why correct sequence is also wrong.
Hi Pankaj, Crystal’s test for blood is a confirmatory test but for a semen sample, the crystal test is a presumptive/screening test because they are based on the detection of choline(Florence test) and spermine (Barberio test) and their detection only give 70% and 26% of a positive result, respectively.