Answer:
In bacteria, the Shine-Dalgarno (SD) sequence is a ribosomal binding motif that is localized upstream the initiation codon and helps to bind the ribosomal subunit. Moreover, the formylmethionine (fMet) on tRNA is found in bacteria and also in eukaryotic organelles
In eukaryotes, the Kozak sequence (A/GCCACCAUGG) is a sequence that helps to start the translation process
Gametophyte
The cells from the male and female that combine to form a zygote are called gametes. The main job of the gametophyte is gamete production. Gametes are haploid reproductive cells. Gametes are produced in the sex organs on the haploid gametophyte by mitosis or cellular division without reduction of chromosomes sets. There are two sex organs; archegonium<span> which is found in the female sex organ producing egg cell and </span>antheridium<span> which is found in the male sex organ producing sperm cells.</span>
Multi cellular organisms are composed of many cells whereas unicellular organisms are composed of single cell. Multicellularity is indeed a progressive attribute of evolution where cells form tissue which forms organ and then organ system and finally an organism. Both multi cellular and unicellular organisms has advantages and disadvantages of their own. One of the main disadvantage of multi cellular organisms is that due to such a complex composition and functioning they require a large amount of energy for their maintenance and survival. Different organs and system require a huge amount of energy when it comes to comparison with unicellular organisms. A large amount of energy is also wasted in all these life processes. Though multi cellular organisms can survive in a variety of environmental conditions but then also their survival is difficult than any unicellular organism.
The Earth was first considered habitable when we discovered that it was Microbial organisms that started the process. I would go with D.
