Answer:
20 million years
Explanation:
If we have a neutral mutation rate of one mutation per 5 million years, then the total of eight mutation between the two different species would be 20 million years. This is because both species will have 4 mutations in those 20 million years, so combined, both by 4, will have 8 mutations between them. So few mutations on so much time will result in two species that are very similar to each other even after 20 million years of evolution, even making them hardly distinguishable, especially if it comes to defining fossil records from them both. A nice example of this are the members of the felidae (cat) family, which are all very closely related, and are almost identical, thus making it extremely hard to distinguish two species of the same or similar size by their fossils.
Answer:
Catabolite repression
Explanation:
Catabolite repression is characteristic for prokaryotic organisms such as bacteria and this is the way to control metabolism.
It is called repression, because enzymes that are involved in other sugar's metabolism are inhibited (repressed). The system of catabolite repression have components such as:
- sensory systems-detects ratios of glycolytic intermediates,
- global regulators-control the expression of genes that encode for enzymes.
Answer:
1. Chromatin condense into chromosomes.
4. Homologous chromosomes pair up (formation of tetrads).
5. Homologous chromosomes separate and move to poles.
2. Sister chromatids separate.
3. Chromosomes unravel in to chromatin.
Explanation:
This question portrays the process of meiosis in a cell. The ordered sequence of events in the options are:
1. Chromatin condense into chromosomes - This process occurs in the Prophase stage. Prior to the cell division, the nuclear material is found as Chromatin material. This Chromatin material then undergoes condensation to form visible chromosomes.
4. Homologous chromosomes pair up (formation of tetrads) - This process also occurs during the Prophase stage of meiosis I. In this stage, homologous chromosomes (similar but non-identical chromosomes received from each parent) are paired up side by side to form a structure known as TETRAD or BIVALENT.
5. Homologous chromosomes separate and move to poles - This process characterizes the Anaphase stage of meiosis I. Homologous chromosomes are pulled apart to opposite poles of the cell by spindle microtubules.
2. Sister chromatids separate - After meiosis I, meiosis II involving sister chromatids instead of homologous chromosomes follows. In the Anaphase stage of meiosis II specifically, sister chromatids are pulled apart towards opposite poles of the cell.
3. Chromosomes unravel in to chromatin - After the whole division process i.e. karyokinesis (division of the nuclear material), the chromosomes begin to unravel to form the CHROMATIN threads once again. This process occurs in the Telophase stage of meiosis.
