Answer:
What is the difference between Metaphase 1 and Metaphase 2? In Metaphase I, the 'pairs of chromosomes' are arranged on the Metaphase plate while, in the Metaphase II, the 'chromosomes' are arranged on the metaphase plate. In Metaphase I, the spindle fibers get attached to two centromeres of each homologous chromosome.
In metaphase 1 the pairs of chromosomes referred to as bivalents are totally condensed. Moreover the in metaphase 1 of meiosis there is no centromere division whereas in metaphase of mitosis it does. They align on the metaphase plate in between the poles.
Explanation:
<h3><u>Answer and Explanation;</u></h3>
- <u>Endosymbiotic theory</u> explains the origin of chloroplasts and mitochondria and their double membrane. Mitochondria of eukaryotes evolved from aerobic bacteria living within their host cell and the chloroplasts of eukaryotes evolved from endosymbiotic cyanobacteria.
- On the other hand according to the <u>autogenous hypothesis, </u>mitochondria and chloroplasts have evolved within the protoeukaryote cell by compartmentalizing plasmids or vesicles of DNA within a pinched off invagination of the cell membrane.
- <u>Endosymbiont theory </u>is the theory that suggests that simple prokaryotic cells were engulfed by larger prokaryotes 1.5 billion years ago.
- <u>Autogenous theory</u> is a theory that was proposed as an alternative to endosymbiont theory. proposes that eukaryotic organelles formed by infolding of the plasma membrane.
- <u>Horizontal gene transfer theory</u> is an alternative to endosymbiont and autogenous theories for the origin of complex organelles in eukaryotes.
Answer:
A mutation can alter the structure/function of a particular protein, thereby also altering the phenotype resulting from this new variant
Explanation:
A mutation can be defined as a genetic change in the genome of an organism. Some mutations are capable of modifying the expression and/or structure of the proteins, while other mutations (known as silent mutations) have no effect on the resulting proteins. When mutations occur within the gene region encoding a protein (i.e., exons), they are potentially capable of producing a faulty protein. For example, a mutation can alter the Open Reading Frame (ORF) of the resulting protein, thereby inactivating it. The mutations that alter the structure and/or function of the protein can also alter the resulting phenotype associated with the expression of this protein. For example, a mutation within a gene that encodes a key enzyme can potentially alter the binding site of the protein, so the resulting mutated enzyme cannot bind to the substrate anymore. In consequence, this mutation alters the phenotype of the individual who is not more able to carry out the metabolic reaction catalyzed by the faulty enzyme.
<span>Ocean current are formed from temperature differences in the same way that wind is formed.
Hope this helps :)</span>
