Scientific Stuff Flashcards
What is an aerogel?
Aerogel is a synthetic porous material created by delicately removing the liquid from a gel and replacing it with gas, making it 99.8% empty. It is nicknamed frozen smoke, solid air, or blue smoke. While aerogel shatters easily, it can support up to 2000 times its own weight. Due to the complex chemicals and manufacturing processes involved, it is very expensive. It has applications in fiber optics and insulation against heat or cold.
How is there water in tender coconut?
A coconut is a seed, and all seeds contain endosperm. The water in a tender coconut is the liquid endosperm. As the coconut matures, this water gets absorbed into the flesh of the coconut.
Why are ceramic tiles stuck to the nose of a space shuttle?
When a space shuttle re-enters Earth’s atmosphere, it faces extremely high temperatures due to air friction. To protect the shuttle and its occupants from burning up, ceramic tiles are attached to the nose of the space shuttle.
Which organism possesses the smallest and largest cell?
Smallest cell: Mycoplasma bacteria, with a diameter of 0.0001 mm.
Largest cell: Nerve cells in a giraffe’s neck, which can be up to 3 meters long.
Why do we need to classify living things?
Scientists estimate that there are between 10 and 100 million different species on Earth, but only less than 2 million have been named. Classification helps us organize, study, and protect species to ensure their survival.
What is genetically modified food (GM food)?
Genetically modified food refers to crop plants created using molecular biology techniques for human or animal consumption. GM foods are modified to:
Resist pests, herbicides, and pesticides
Improve nutritional content
Grow faster for larger yields
Withstand droughts
Produce medicines and vitamins
Soybean and corn are the top two genetically modified crops.
What are the possible harmful side effects of GM food?
GM crops can produce toxins that may kill useful insect species.
Over time, insects may develop resistance to GM crops’ pesticides.
Crossbreeding between GM crops and weeds may create superweeds that are herbicide-resistant.
Some children in the US and Europe have developed life-threatening allergies to GM foods like peanuts and wheat.
New allergens may be created in GM foods, potentially causing allergic reactions in some people.
What are lichens?
A lichen is a symbiotic relationship between a fungus and an algae. Lichens resemble fungi but contain chlorophyll, allowing them to produce their own food.
How do echinoderms (sea stars, urchins, sea cucumbers) move?
Echinoderms are invertebrates that move slowly using small tube-like structures on their body called podia. These podia expand when filled with water by the water vascular system. Small muscles inside the echinoderm contract the podia, causing movement. The cup-like structures at the tip of the podia produce strong suction, allowing them to stick to solid surfaces.
How are insects like bees attracted to flowers?
Flowers with bright colours and nectar attract insects and birds. When bees and birds land on flowers for nectar, pollen grains stick to them and are transferred from flower to flower. Different parts of the flower reflect ultraviolet rays, which bees can detect to locate nectar.
Does the number of bones in our body change as we grow?
At birth, a human has over 300 bones, but as we grow, some bones fuse together. An adult human has 206 bones in the body.
