Answers to Last Issue's Do You Know?
1. How much brainpower do our senses take up, and is there one that takes up the most?
Ans: We don't actually have five senses, which we normally call sight, hearing, taste, touch and smell. In fact, touch is broken down into several components due to how some nerves pick up on some things. So touch/motion/self perception are broken down into lots of things. In any case, brain power could be thought of as the amount of blood flowing into the brain region to do its job (bringing oxygen and calories) or how much physical space of your brain is dedicated to a particular sense.
Visual Processing: The occipital lobe, located at the back of the brain, is primarily responsible for visual processing. It receives and interprets signals from the eyes, accounting for a significant portion of the brain's sensory processing capacity.
Auditory (Sound) Processing: The temporal lobe, particularly the primary auditory cortex, processes sound. It also plays a role in language comprehension and memory, which can overlap with auditory processing.
Taste and Smell: The gustatory cortex (taste) and olfactory bulb (smell) are involved in processing taste and smell, respectively. These senses are closely linked; for instance, taste is heavily influenced by olfactory signals.
Touch: The parietal lobe contains the somatosensory cortex, which processes tactile information such as pressure, temperature, and pain.
(Image from https://www.tributeseniorliving.com/wp-content/uploads/2022/03/how-brain-works-2.jpg)
While it’s difficult to assign specific percentages of brain capacity to each sense, studies suggest that a large portion of the brain—up to 30% or more—may be involved in processing sensory information, with visual processing often taking the largest share. The exact distribution can vary among individuals and depends on factors such as experience and training.
However, many senses often work together, like smell and taste. For instance, proprioception (or kinesthesia), is the body's ability to sense its position and movement in space. It allows you to know where your limbs are without looking and to make adjustments to your posture and movements without conscious thought. This sense relies on proprioceptors, specialized sensory receptors located in muscles, tendons, and joints. It could be argued that it takes the "most power" to process propprioception, because this "sense", under normal conditions (like walking down the street and waving to someone) would require bits of other senses: touch, vision, movement, balance, etc...
It is also important to remember that neurons do not have "off" switches. They never goof off; they're "on," alert, armed and ready for action. So if one sense is using up 10% of your brain power, doesn't mean that the rest of the brain has gone to sleep! It is working 100% of the time, waiting for a signal that needs some action. This also needs energy.

2. Why do some people get bitten by mosquitoes more than others?
Ans: Mosquitoes bite some people more frequently than others due to a combination of factors. Clothing choices and even alcohol consumption can alter this.
1. Body Odour and Sweat: Mosquitoes are attracted to the various chemicals found in human sweat. The smell of a person is influenced by genetics, diet, and skin bacteria. Sweatier persons or those with higher body temperatures tend to attract more mosquitoes.
2. Carbon Dioxide Exhalation: Mosquitoes detect carbon dioxide from a distance and use it as a cue to locate a potential blood meal. Larger individuals and pregnant women, who naturally exhale more carbon dioxide, may be targeted more frequently.
3. Skin Bacteria: The composition of bacteria on our skin varies from person to person and can influence attractiveness to mosquitoes.
4. Blood Type: Research suggests mosquitoes are more attracted to people with type O blood. This may be due to specific chemicals released through the skin by people with certain blood types.
5. Other Factors: Darker clothing can make individuals more noticeable to mosquitoes. Studies suggest that alcohol consumption, particularly beer, may increase mosquito attraction. Even our genes play a role in determining our unique scent and attractiveness to mosquitoes.

3. Can we make a plant entirely “from scratch” using only DNA?
Ans: The short answer is, Not yet. To design and build entire plant genomes, that is, making DNA sequences in the lab, assembling them into functional units like chromosomes, and then introducing them into plant cells, is still quite a challenge.
What has been achieved so far? Scientists can now synthesize DNA from scratch using DNA synthesizers, allowing them to create custom DNA sequences. This means that they can design of new genetic codes and even construct entire genomes. The synthesized DNA sequences are then assembled into larger structures, like chromosomes. This means that techniques to build synthetic chromosomes already exist for simpler organisms like yeast and some human cell lines. The process by which these synthetic chromosomes or other genetic elements are introduced into plant cells is called transformation. This is where challenges remain. Various methods are being tested and developed to efficiently perform transformation for plants. This is still an active area of research. The ultimate goal is to create a plant that can grow and reproduce from this synthetic genome. This will enable us to create crops with new traits and capabilities. For example, development of crops with increased resilience to climate change, improved nutritional content, are important aspects of this research. It could also lead to a better understanding of plant biology and evolution.

4. Do fish in the deep sea experience seasons?
Ans: Yes, deep-sea fish can experience seasonal changes, though not in the same way as surface-dwelling organisms. The most prominent seasonal changes in the ocean occur at the surface, influenced by sunlight and weather patterns. How does this affect deep sea season? Algal blooms are produced in sunlight. These slowly sink to the sea bed as "marine snow" and become food for the deep-sea ecosystem. This "marine snow" creates seasonal patterns in food availability for deep-sea organisms.
Researchers have documented seasonal migrations of deep-sea fish, suggesting that they respond to these variations in food supply. But as you go deeper, at 3-5 km under water, there will be hardly any marine snow. This has more influence near continental shelves.
The extent of seasonal influence varies with location. Fish and other marine life in some deep-sea regions (particularly those far from continental shelves or major current systems), may not experience these seasonal changes. So, for example, in the middle of the Atlantic and Pacific oceans, the bottom water is mostly unaffected by seasonal changes in surface waters.
Compiled from many sources