QUES: Bacteria often attach to surfaces and form dense aggregations called biofilms or bacterial mats. These films can range from a few micrometers in thickness to up to half a meter in depth, and may contain multiple species of bacteria, protists and archaea. Bacteria living in biofilms display a complex arrangement of cells and extracellular components, forming secondary structures, such as microcolonies, through which there are networks of channels to enable better diffusion of nutrients. In natural environments, such as soil or the surfaces of plants, the majority of bacteria are bound to surfaces in biofilms. Biofilms are also important in medicine, as these structures are often present during chronic bacterial infections or in infections of implanted medical devices, and bacteria protected within biofilms are much harder to kill than individual isolated bacteria.

How extent can biofilm be?
What is the answer?
ANS: up to half a meter in depth
QUES: Isolated remains of Homo erectus in Hathnora in the Narmada Valley in central India indicate that India might have been inhabited since at least the Middle Pleistocene era, somewhere between 500,000 and 200,000 years ago. Tools crafted by proto-humans that have been dated back two million years have been discovered in the northwestern part of the subcontinent. The ancient history of the region includes some of South Asia's oldest settlements and some of its major civilisations. The earliest archaeological site in the subcontinent is the palaeolithic hominid site in the Soan River valley. Soanian sites are found in the Sivalik region across what are now India, Pakistan, and Nepal.

From how long ago do tools date in India?
What is the answer?
ANS: two million years
QUES: Starting in 2006, Apple's industrial design shifted to favor aluminum, which was used in the construction of the first MacBook Pro. Glass was added in 2008 with the introduction of the unibody MacBook Pro. These materials are billed as environmentally friendly. The iMac, MacBook Pro, MacBook Air, and Mac Mini lines currently all use aluminum enclosures, and are now made of a single unibody. Chief designer Jonathan Ive continues to guide products towards a minimalist and simple feel, including eliminating of replaceable batteries in notebooks. Multi-touch gestures from the iPhone's interface have been applied to the Mac line in the form of touch pads on notebooks and the Magic Mouse and Magic Trackpad for desktops.

Which material did Apple add with the 2008 unibody MacBrook Pro?
What is the answer?
ANS:
Glass