Passage Based Questions[Forensic Science]

Read the passage carefully and answer the following questions (1-5)- 

• A dead body was recovered from riverbed. The body was found tied to a stone with a 3 ply coir rope to prevent the body from floating. A suspect who was an inimical terms with the deceased was arrested. On the search of his premises a piece of rope, similar in thickness & ply, was found tied to a log in the cowshed. On examination of the 2 rope pieces, it was possible to establish that they both formed part of same piece. This evidence was led to establish the complicity of the suspect in the crime.

Q1- Which among the following information will be determined, if diatoms found inside the dead body?​ 

1. Time of death
2. Place of death
3. Type of death
4. all of these

ANSWER-4

EXPLANATION:-

• Time of Death =

1. If fewer than 20 different species of colonizing diatoms- Death within the previous 7 to 12 days.
2. I​f more than 50 different colonies of diatoms - death possibly occurred several weeks ago.

• Place of death =​ By examining the species of diatoms under microscope.

• Type of death =

1. Ante-mortem Drowning – Diatoms found inside the lungs, liver, respiratory organs.​
2. Post-mortem Drowning - Diatoms found on the surface of body. 

Q2- Which among the following extraction method is commonly used for Diatoms?

1. Tungustate method
2. Solvent extraction method
3. Acid digestion method
4. Ammonium sulphate method

ANSWER-3

Q3- Study of diatoms is known as-

1. ​Forensic limnology
2. Forensic Palynology
3. Forensic Dendrochronology
4. Forensic Systematics

ANSWER-1

EXPLANATION:-

1. ​Forensic limnology - study of aquatic environments(Diatoms)
2. Forensic Palynology - study of pollens
3. Forensic Dendrochronology - study of tree rings
4. Forensic Systematics - classification of plants

Q4- Which among the following is not correct about diatoms?

1. Generate about 20 to 50% of the oxygen produced on the planet each year.​
2. Group of algae, specifically micro algae​
3. Multicellular ​
4. Found either as solitary cells or in colonies​
5. All are correct

ANSWER-3

EXPLANATION:-

• Diatoms are unicellular & have shape of ribbons, fans, zigzags, or stars. ​
• Individual cells range in size from 2 to 200 micrometers.​
• maximum life span of individual cells is about six days.​
• A unique feature of diatom anatomy- they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule.​
• These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as "jewels of the sea" and "living opals". 

Q5- Diatoms were first detected in lung fluid by?

1. Hofmann​
2. Incze​
3. Tamasaka​
4. Porawski

ANSWER-1

EXPLANATION:-

• Hofmann- Diatoms were first detected in lung fluid. ​
• Incze- detected diatoms in blood and parenchymal organs and demonstrated that diatoms could enter into the circulation through lungs. ​
• Tamasaka- Diatoms were detected in bone marrow. ​
• Porawski- showed presence of diatoms in organs and bone marrow is indication of the antemortem inhalation of water during drowning.