Homologous chromosomes pair up and exchange segments of DNA.
Option A
<h3><u>Explanation:</u></h3>
Crossing over is an event of Prophase 1 of meiosis 1. It occurs in the zygotene phase of prophase 1. Here the homologous chromosome pairs get very close together and gets packed within protein coat. The enzymes randomly cut the DNA segments from both chromosomes at same loci and exchange them with each other. This results in the exchange of genes between the two chromosomes. This is how the variation comes to place between offsprings of the same individuals. The crossing over results to form X shaped intersections between homologous pair of chromosomes which is called as chaismata. This phase occurs in pachytene phase and is visible in diplotene phase when the protein coat dissolves.
Answer: low frequency & low energy
Explanation:
Tissues and organ systems.
here is the full chart:
cell --> tissue --> organ --> organ system --> organism
(think: group of [insert former here])
e.g. tissue=group of same cells
(et.al)
Explanation is in the file
tinyurl.com/wpazsebu
Answer:
3, 1, 4, 5, 2
Explanation:
DNA helicase enzyme will unwind DNA into 2 segments for a template. Complementary nitrogenous bases will attach themselves to one of the DNA strands. mRNA carries codons for instructions from DNA. mRNA leaves the nucleus and joins with a ribosome (tRNA) in the cytoplasm. tRNA has anticodons which are complementary to a specific mRNA molecule. tRNA pairs with and translates instructions that the mRNA is carrying. Each amino acid delivered to the ribosome by tRNA begins forming a chain of amino acids, called a peptide bond.
