(a) genes introduced in the genetically modified plants 

(b) development of India’s own satellite navigation system 

(c) radio collar for wildlife tracking 

(d) spread of viral diseases 

Ans: d

Explanation:

The angiotensin-converting enzyme 2 (ACE2) is a protein that has different roles such as catalytic, transporter of amino acids or viral receptor. It has an essential role in different systems, from cardiovascular regulation to viral infection. 

The ACE attaches to cell membranes and works as the host functional receptor for the virus SARS-CoV-2 which causes Coronavirus Disease 2019 (COVID-19).  

The SARS-CoV and the SARS-CoV-2 enter the human cell through the ACE2 receptor. 

These two viruses have a surface anchored Spike (S) glycoprotein with surfaces receptor binding domains (RBD).

These two structures are critical for the entrance of the virus into the human cell. When the genetic material of the virus enters the cell, the membrane of the virus fusions with the host membrane cells. 

SARS-CoV-2 has a significantly higher ACE2 binding affinity.

The 3-dimensional structure of the SARS-CoV-2 binding site has a more compact conformation, improved binding stability, and potentially enhances the ACE2 receptor binding affinity.

ACE2 expression

ACE2 is widely expressed in many different cells of the body. 

It was observed to be highly expressed in endocrine tissues, gastrointestinal tract (e.g. ileum, liver and gallbladder), cardiovascular tissues, kidney and urinary bladder, testes and muscle tissues. 

It was observed that central nervous system and lymphoid tissues express relatively low ACE2 levels. 

They found that that the receptor it is not expressed in red blood cells. 

In the lung, high mRNA ACE2 expression was detected in the parenchyma and in primary and tertiary bronchi. Relevant for the transmission and respiratory manifestations of SARS-CoV-2 

Hence, option d is correct.

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