Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. Almost all skin cancers (approximately 99% of non-melanoma skin cancers and 95% of melanoma) are caused by too much UV radiation from the sun or other sources such as solaria (solariums, sunbeds, and sun lamps).
The Largest Animal Ever: The Blue Whale. The blue whale(Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales. At 30 metres (98 ft) in length and 180 metric tons (200 short tons) or more in weight, it is the largest known animal to have ever existed.
Q3. In each testes in a male reproductive system, there are ________ compartments called testicular lobules.
पुरुष जनन तंत्र के प्रत्येक वृषण में लगभग ______ कक्ष होते हैं जिन्हें वृषण पालिका कहते हैं|
The life cycle of most mosses begins with the release of spores from a capsule, which opens when a small, lidlike structure, called the operculum, degenerates. A single spore germinates to form a branched, filamentous protonema, from which a leafy gametophyte develops.
Q5. Which among the following does not have a cell wall?
निम्नलिखित में से किस में कोशिका भित्ति नहीं होती है?
Mycoplasma is a genus of bacteria that lack a cell wall around their cell membrane. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis. They can be parasitic or saprotrophic.
Q6. Which among the following is also called as ‘power house of the cell’?
निम्नलिखित में से किसको ‘कोशिका का शाक्तिगृह’ भी कहा जाता है?
Mitochondria are rod-shaped organelles that can be considered the power generators of the cell, converting oxygen and nutrients into adenosine triphosphate (ATP). ATP is the chemical energy “currency” of the cell that powers the cell’s metabolic activities.
Q7. Which component in tobacco makes it harmful for human consumption?
तंबाकू का कौन सा घटक उसे मानव उपभोग के लिए हानिकारक बनाता है?
Biochemical oxygen demand (BOD, also called biological oxygen demand) is the amount of dissolved oxygen needed (i.e., demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
Physiology – Physiology seeks to understand the mechanisms that work to keep the human body alive and functioning, through scientific enquiry into the nature of mechanical, physical, and biochemical functions of humans, their organs, and the cells of which they are composed.
Phrenology – Phrenology is a pseudo medicine primarily focused on measurements of the human skull, based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions or modules.
Mycology – Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicine, food, and entheogens, as well as their dangers, such as toxicity or infection.
Biology – Biology is the natural science that involves the study of life and living organisms, including their physical and chemical structure, function, development and evolution.
Q10. Which of the following bacteria is responsible for the formation of curd?
निम्नलिखित में से कौन सा जीवाणु दही के गठन के लिए उत्तरदायी होता है?
When milk is heated to a temperature of 30-40 degrees centigrade and a small amount of old curd added to it, the lactobacillus in that curd sample gets activated and multiplies. These convert the lactose into lactic acid, which imparts the sour taste to curd.