The answer is A. The sample from a crime scene does not have enough DNA to perform forensics tests such as DNA matching. PCR -polymerase chain reaction - is used to amplify the DNA to required amount. Each cycle of PCR amplifies DNA two-folds
The soil because they can't live without it because plants grow in it and prvide them with food
If the water molecule was linear instead of bent, water
would no longer produce hydrogen bonds. It will lose its polar properties and
nearly all of its properties will change such as boiling point, water tension
and solubility. It would be closer to gas, rather than liquid.
A is correct. We know that water buildup is essential for plants (and all other organisms) that live in the desert due to its lack of moisture. So, the question is simply asking which adaptation will help a plant retain the most water in the desert. Here’s what makes each wrong or right:
A. Stem that stores water - Having stems that can retain a lot of moisture and water is absolutely necessary for plants that live in hot and dry biomes. The brief periods of rain in the desert make it easier for plants with water-storing stems to absorb the water and remain hydrated throughout their time. This is referred to as succulence, and most (if not all) plants in the desert are succulents. This is the correct answer!
B. Shallow root system - Many plants that live in deserts tend to have shallow root systems that allow them to quickly absorb and moisture in the environment — and because water never goes too far in the desert, they soak most of it up. Although this is helpful, it is better for plants that live in places with a lot of soil.
C. Large surface area - Having a large surface area is more useful for photosynthesis and may result in dehydration. This is wrong!
D. Flat broad leaves - Again, this adaptation is more favorable for plants that do not live in the desert because, as we know, photosynthesis requires water.
Answer: Like us, fish also need to take in oxygen and expel carbon dioxide in order to survive. But instead of lungs, they use gills. ... As the fish opens its mouth, water runs over the gills, and blood in the capillaries picks up oxygen that's dissolved in the water.
