Answer:
Chlorophyll is a green pigment found in chloroplast in plants. It absorbs sunlight during the process of photosynthesis. It is a chelate molecule. In a chelate molecule a central metal ion forms bonds with a large organic molecule made of carbon, hydrogen and other elements like nitrogen or oxygen. 
In chlorophyll, magnesium is the central metal ion and it is bonded to a large organic molecule called as porphyrin. Porphyrin constitutes four nitrogen atoms to which the central magnesium is bonded in square planar arrangement. Since chlorophyll is responsible for the green color of the leaves, more the green color more the chlorophyll content and more is the nitrogen content. Hence, chlorophyll meter measures this green light and finds out if the plant needs more or less nitrogen. 
 
        
             
        
        
        
1 ) The first terrarium was developed by botanist Nathaniel Bagshaw Ward in 1842. He was interested in studying insect behaviour. Once he accidentally left one of his bug jars open. A fern spore in the jar sprouted, grew and germinated into a new plant. This is how the first terrarium had been created.
2 ) <span />Because of the different conditions within, terrariums there are two, which can be classified as closed and open. Closed terrariums have a lid to enclose the plants entirely within the glass container. Open terrariums do not require a lid.
Sorry working on this right now as well, and I don't have the others yet :(
<span><span>
</span></span>
        
             
        
        
        
Answer:
<u>Perilymph</u> is a fluid similar to cerebrospinal fluid that fills the space between the bony labyrinth and the membranous labyrinth.
Explanation:
The inner ear consists of the bony labyrinth and the membranous labyrinth, it is filled of endophilia and surrounded by perinfilia (the bony labyrinth surrounds the membranous, between both there is a space occupied by the perilymph). Perilymph is an albuminous fluid that has an ionic composition similar to the extracellular environment, it bathes the tympanic and vestibular ramps, fully occupying the bony cavities of the inner ear, bathing the membranous parts located inside these cavities.
 
        
             
        
        
        
Answer:
The geologic time scale is an important tool used to portray the history of the Earth—a standard timeline used to describe the age of rocks and fossils, and the events that formed them. It spans Earth's entire history and is separated into four principle divisions.
Explanation: