I think the correct answer from the choices listed above is option B. You can find methanogens in the human intestines. These organisms can work with or without oxygen. Too much of oxygen for them is toxic. They are obligate anaerobes.
Echinoderms have radial symmetry.
Answer:
The spindle fibre is necessary to separate the sister chromatids into opposite sides of the cell.
Please find detailed explanation below
Explanation:
Mitosis is the cell division that produces two daughter cells that are genetically identical to the parent cell. Mitosis occurs in stages viz: prophase, metaphase, anaphase and telophase. The replicated chromosome, aligns at the centre of the cell in the METAPHASE stage and separates into opposite poles in the ANAPHASE stage.
This alignment (at the equator) and separation into opposite pole is possible with the aid of a structure called SPINDLE FIBRES. Spindle is a structure formed from microtubules, which attach to the kinetochores (located in the centromere) of each replicated chromosome to separate them from one another. Hence, the purpose of the spindle fibre during mitotic division is to separate the GENETIC MATERIAL of a parent cell into two daughter cells.
The DNA that contains your genes is stored in your cells in a structure called the nucleus.