Annular eclipse occurs when the sun's center is covered by the moon
"Severe combined immunodeficiency (SCID)" can be caused by "failure of VDJ recombination".
Option D
<u>Explanation</u>:
- "SCID" is "inherited immune system disorder" which happen due to abnormalities in the response of both T and B cells which are needed for the proper functioning of the immune system.
- VDJ occurs in genetic recombination occurring in the early or developing stages of lymphocytes.
- Somatic recombination is also a part of VDJ which results in immunoglobulin's, which is "defining feature" of the immune system and the same which causes severe combined immunodeficiency.
Answer:
Characteristics that have helped humans survive major changes in the environment are their brains and body. Human's social cooperation with tool making always increases.