According to this phylogenetic tree, which of the following pairs of organisms is the most closely related? A Sharks and ray-finned fishes
B Amphibians and primates
C Primates and rodents/rabbits
D Rodents/rabbits and birds

By looking at the phylogenetic tree, we can tell which taxonomic groups are more closely related to each other or less related. In this phylogenetic tree, primates and rodents/rabbits is the pair most closely related.

The phylogenetic tree is composed of,

⇒ Highly related groups that share a recent common ancestor. This means that they all diverge from the same node.

⇒ Lineages less related to each other are those whose common ancestor is far away in history.  

In the exposed pylogenetic tree, there are two groups of linages that are closely related to each other.

These two groups share a common ancestor farther away, which is the point from where each group diverge.

Among the given options, we have

A) Sharks and ray-finned fishes ⇒ Not closely related

B) Amphibians and primates ⇒ Not closely related

C) Primates and rodents/rabbits ⇒ CLOSELY RELATED

D) Rodents/rabbits and birds ⇒ Not closely related

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According to this phylogenetic tree, which of the following pairs of organisms is the most closely related?

C. Primates and rodents/rabbits

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.