Answer:
Primary active transport directly uses a source of chemical energy (e.g., ATP) to move molecules across a membrane against their gradient.
<span>D. 9 </span>
<span>Notice that diploid cells which 18 are the complete number of chromosome pair of the organism. This usually happens under cell divison –mitosis which process of replicating oneself to produce another like cell. Meiosis occurs in gametes, sex cells. Their respectively called spermatogenesis (sperm cells) and oogenesis (egg cells). These cell division –meiosis produces haploid cells, in which in words “half” from the complete cell chromosome number, hence, these </span>haploid cells<span> only produce half number or one set of chromosome (9) instead of the complete pair which in this case, 18.<span>
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<span>The biggest difference between the elements and the compounds is that elements are substances that cannot be separated into simpler substances and more elements chemically joined combined make a compound.
</span>In a compound th<span>e atoms lose their individual properties and have different properties from the elements they are composed of.
</span><span> The smallest particle of an element that has the properties of that element is the atom.</span>
