This primitive fish was the ancestor of land-dwelling tetrapods (amphibians, reptiles, mammals and birds), although fish of this type still exist in the modern deep ocean:
a) jawless fish.
b) lobe-finned fish.
c) placoderms.
d) ray-finned fish.

The correct answer is option B. lobe-finned fish.

Explanation:

Lobe finned fishes or the Sarcopterygii is a group or clad of fish that contain the coelacanths, tetrapods, lungfish, and other fossil relatives. ray-finned fishes and lob finned fishes are the are sister groups.  

The major characteristic feature of this fish is the presence of lobe in their fins. The ancestral records explained that the land-dwelling tetrapods are evolved from the lobe-finned fishes around four four hundred million years ago.

Thus, the correct answer is option B. lobe-finned fish.

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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