Questions

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

The process of conversion of sugar to alcohol is called Fermentation in which sugar is coverted to alcohol with the help of yeast.

A 40% solution of Formaldehyde known as Formalin is used in the preservation of biological specimens because of its hardening action on proteins. 

23 chromosomes are in a human gamete.

Human somatic cells have 46 chromosomes(23 pairs) but a gamete(germ cell) gets half the amount, i.e. 23 chromosomes, (one from each pair). There will be half the number of chromosomes an organism has in its somatic cells (all other body cells except gametes).

For example in humans, the somatic cells contain 46 chromosomes which are the diploid number (2n) and each sperm and egg has 23 chromosomes where one of them is the sex chromosome.

Author of the book A journey  is Tony Blair

Mutex is the short form for ‘Mutual Exclusion object’. A mutex allows multiple threads for sharing the same resource. The resource can be file. A mutex with a unique name is created at the time of starting a program. A mutex must be locked from other threads, when any thread that needs the resource. When the data is no longer used / needed, the mutex is set to unlock.