Answer: Membrane transport proteins are specific and selective for the molecules they move, and they often use energy to catalyze passage. Also, these proteins transport some nutrients against the concentration gradient, which requires additional energy.
Explanation:
After two half-lives or 60 years, 7.5 g of the element will be left.
<u>Explanation:</u>
<u>Half-life:</u>
- In simple words, Half-life can be defined as the amount of time needed for a quantity to fall to half its value as contained at the beginning of the time period.
- In this problem the half-life of the element is thirty years, then after thirty years half of the sample would have decayed and half would be left as it is.
- After thirty years (The first half-life ) 30 /2 = 15 g declines and 15 g remains disappeared.
- And after another sixty years (The two half-lives) 15 /2 = 7.5 g declines and 7.5 g remains disappeared.
- After two half-lives or 60 years, 7.5 g of the element will be left.
Answer:b. an mRNA transcript to which multiple ribosomes are attached
Explanation: polysome consist of mRNA complex and two or more ribosome coming together to translate mRNA into a polypetide or amino acid. It helps produce many polypeptide from a single mRNA.
Different ribosomes bind to the mRNA at different time elongating the polypeptide chain. We have the free( non-poly A ) and memberane bound (poly A) polysome.
Answer:
Chromosomes must still be copied.
the cell must double in size.
the nuclear DNA must double.
Explanation:
