The circulatory system helps in the exchange of gases, nutrients, and hormones. Crab have an open circulatory system. Therefore option D is correct.
There are two types of circulatory system :
In open circulatory system there are no blood vessels and blood flows in open cavities. It is seen in arthropods and many molluscans species.
In closed circulatory system there are blood vessels and blood flows in blood vessels. This type of circulatory system is seen in mammals, Aves and other phylum as well.
Lizard belongs to phylum reptiles and have closed circulatory system. Bird belongs to phylum Aves and have closed circulatory system. Dog is a mammal and have closed circulatory system. Crab is an arthropod and have open circulatory system.
Therefore, Crab is an arthropod and it have open circulatory system. Hence, the correct option is D.
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One component of the cell theory is A cell is the basic unit of structure and function of all organisms. Thus, option "D" is correct.
The cell contains genetic material in the form of DNA which is passed from the parent cell to the daughter cells after cell division.
All cells are similar in chemical composition as well as in metabolic activities.
All the physiological and biochemical functions usually take place inside the cell.
The activity of the cell depends upon the cell organelles and other cellular parts.
Thus, option "D" is correct.
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Answer:
A cell is the basic unit of structure and function of all organisms
Explanation:
All other options are wrong
The correct answer is - B. The rock formed in a fast moving stream.
The rocks that have ripples are a relatively easy when it comes to guessing where they formed and under what conditions. The reason for that are the ripples themselves, as they are formed only because of the influence of water or wind, though it is mostly the water.
If we see a rock with ripples, the chances are that that rock has formed in place where it was influenced by water for prolonged period of time. The best guess would be a fast moving stream, as the water will have bigger power, and will be able to have bigger influence on the rock and make its ripples.
Answer:
P-waves travel through the fluid layers of Earth's interior, and yet are slightly refracted as they pass through the transition between the semi-solid mantle and the outer core liquid.
adenine
ermine
tidine
2.fluorine
purine
thymine
thalamine​
The four types of nitrogen bases of DNA nucleotides are adenine, thymine, guanine and cytosine.
DNA is defined as deoxyribonuclic acid and it is a polymer made up of two polynucleotide chains that arranged in foiled structure to form a double helix carrying genetic information for the various processes such as growth development functioning and reproduction.
There are four nitrogen bases of DNA nucleotides are such as adinine, thymine, guanine and cytosine.
Friedrich miescher discovered DNA in the year of 1860.
The main function of DNA is to carry information from one generation to another generation this is the reason due to which DNA is also known information molecule.
In our body DNA is found in the nucleus of the cell and it is known as nuclear DNA.
The shape of DNA is double helical structure.
Siblings share only about 50% of same DNA due to the reason of recombination. The life span of DNA is 521 years.
Therefore,the four types of nitrogen bases of DNA nucleotides are adenine, thymine, guanine and cytosine.
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Answer:
1. Adenine
2. Thymine
Explanation: