Nucleus
..............................................................................
The best answer is pneumatophores.
In the environment where mangroves grow, oxygen is very limited. This necessitates mangrove root system to take up oxygen from the atmosphere. For this purpose, mangrove species have specialized above ground roots called pneumatophores or breathing roots.
In some species, these roots are pencil sized and peg-like while in others they look like a knee. These roots have numerous pores through which oxygen enters into the underground tissues. In some plants, buttress roots function as breathing roots and also provide mechanical support.
<span>A scientist is determining the age of a rock by comparing their position to other rock layers. By doing this, the scientist is determining the relative age of the rock. </span>
Answer:
adenine pairs with Thymine and guanine always pairs with cytosine respectively
Explanation:
In DNA nucleotide subunits, there are four nitrogenous bases:
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
Each of these bases can be divided into two categories: purine bases and pyrimidine bases.
Adenine and guanine are examples of purine bases. This means their structure is a nitrogen-containing six atom ring joined with a nitrogen-containing five atom ring that share two atoms to combine the two rings.
Thymine and cytosine are examples of pyrimidine bases.
Note that RNA replaces thymine with a different pyrimidine base called uracil (U).
The complementary base pairing rule, Chargaff's rule states that DNA base pairs are always adenine with thymine (A-T) and cytosine with guanine (C-G). A purine always pairs with a pyrimidine and vice versa. However, A doesn't pair with C, despite that being a purine and a pyrimidine.
