The ABO blood group is a classification of blood depending on the presence of how many antigens?

Suppose you found a fossil of a clam shell what can you conclude about the once-living organism and how it became a fossil?

Stolb23 [73]

Answer:

Identifying the fossil is the first step. We have already identified this fossil as a clamshell. We know clam are from the sea, but if you didn't, you could conclude this from knowing where you found the fossil (likely near the beach). Discovering where it is can also lead you to a conclusion on it's arrival as a fossil, perhaps washed up on shore or buried by an animal.

Explanation:

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3 years ago

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When cleaning up water pollution in a large lake or river, it is important to clean up the entire??

love history [14]

When cleaning up water pollution in a large lake or river, it is important to clean up the entire watershed. It is a basin-like landform defined by highpoints and ridgelines that descend into lower elevations and stream valleys. This is because pollution can be transfered to other areas of the lake or the river when this part is not cleaned well.

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3 years ago

What is a period in chemistry

Leviafan [203]

A period is the name given to a horizontal row of the periodic table. The periodic table has seven periods. Period 1 contains only two elements: hydrogen and helium.

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3 years ago

DNA has the appearance of a _____. DNA has the appearance of a _____. single strand letter U double helix triple helix circle

Kitty [74]

Answer:

double helix

Explanation:

Deoxyribonucleic acid, commonly known as DNA, consists of two long polynucleotide chains composed of four types of nucleotide subunits i.e. A, G, C, T. Each chain is called a strand. Each nucleotide is made up of a pentose sugar, phosphate group and a nitrogenous base.

DNA is a double-helical structure that contains each strand in a spiral or coiled form. This double helix structure forms when two complementary strands are held together by hydrogen bonds. The bonding occurs between the nucleotide base portions of the complementary strands e.g G-C, A-T.

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3 years ago

Bacteria and other microbes can be used to "clean up" an oil spill by breaking down oil into carbon dioxide and water. Two sampl

vlada-n [284]

Answer:

Sample A: Thymine= 20.7% ; Adenine= 20.7%; Guanine = 29.3% ; Cytosine= 29.3%

Sample B: Thymine= 30.9% ; Adenine= 30.9% ; Guanine= 19.1% ; Cytosine base= 19.1%

Explanation:

In a double-stranded DNA molecule, the percentage of adenine base is equal to that of the thymine base while the percentage of guanine base is equal to that of the cytosine base. It is called Chargaff's rule and is based on the complementary base pairing of purine and pyrimidine bases.

Sample A: Percentage of thymine= 20.7%

This means that the sample has= 20.7% adenine base

Total thymine and adenine bases in sample A= 20.7 + 20.7 = 41.4%

Therefore, proportion of guanine + cytosine bases in the sample= 100-41.4= 58.6%

Percentage of guanine base= 58.6/2 = 29.3%

Percentage of cytosine base= 29.3%

Sample B: Percentage of thymine= 30.9%

This means that the sample has= 30.9% adenine base

Total thymine and adenine bases in sample A= 30.9 + 30.9 = 61.8%

Therefore, proportion of guanine + cytosine bases in the sample= 100-61.8= 38.2%

Percentage of guanine base= 38.2/2 = 19.1%

Percentage of cytosine base= 19.1%

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3 years ago