1. The appearances of fireflies at dusk is an example of a circadian rhythm because it's happens daily. The correct option among all the options that are given in the question is the third option or option "c".
2. During migration, animals undertake a seasonal movement. The correct option among all the options that are given in the question is the first option or option "a".
E-coli bacteria which most useful in the routine monitoring of microbial pollution are gram negative rods and this is common indicator organism of water contamination.
It is important to identify enteric bacteria which is one of the major causes of diarrhea disease is bacteria and that detection of pathogenic bacteria is a global key to the prevention and identification of food borne diseases and enteric infections like diarrhea.
The extent of water contamination can be measured using these indicator organisms. This fecal coli-form group has been used as the most common indicator of general wastewater contamination because they are abundant and easy to identify.
To learn more about E-coli bacteria here
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Answer: Spinal cord.
Explanation:
The spinal cord of the central nervous system helps to move off quickly as a part of the reflex response. Jill stepped on a tack and suddenly he realizes that he should quickly move his legs out of the tack.
The pain is not stimulated until the signals reaches from the receptor to the brain. The formation of the reflex arc ensures that the amount of potential tissue damaged is less.
It forces the body to move quickly from the place that is causing damage.Example: Moving the leg up involuntarily when stepped on pin.
This occurs because the sensory neurons connects to the motor neurons within the spinal cord.This leads to the contraction of bones and muscles.
Hence, the correct option is spinal cord.
Answer: There are two ways to determine the age of a dinosaur fossil. One is called relative geologic time, which involves deciding whether one dinosaur fossil is older or younger than another. Geologists then measure the proportion of parent and daughter atoms present in the ash crystals to determine the crystal's age.
Explanation:
Answer:
Explanation:
Given that,
The mass of a sample, m = 16.7 grams
Volume of the sample, V = 4.4 cm³
We need to find the density of the metal sample.
Density = mass/volume
Substituting all the values,
So, the density of the metal sample is 
.
