Ribosomes are attached to<span> the </span>membrane<span> of the </span>ER, making it “rough<span>.” The RER is also </span>attached to<span> the nuclear envelope that surrounds the nucleus.</span>
B. a specific place on a chromosome where a particular gene resides.
A locus (plural loci) in genetics is the position of a gene on a chromosome. Each chromosome carries many genes; humans' estimated 'haploid' protein coding genes are 19,000-20,000, on the 23 different chromosomes. A variant of the similar DNA sequence located at a given locus is called an allele.
Answer:
A. Many dinosaurs were present in upper layers of rock strata, but not in lower layers.
Explanation:
In my opinion, this is the best possible answer.
Each "human body cell" has 46 chromosomes. But human sex cells have 23 unpaired chromosomes in each cell. Sex cells are created by a special type of cell division, Meiosis.
