Answer:
In the first step of meiosis I, the chromosomes/genetic material of the cell condenses into a visible form, into a form called heterochromatin. The nucleolus also disappears.
In the second step, a process called synapsis occurs. This is when homologous chromosomes align themselves, gene by gene.
In the third step, crossing over occurs. Segments of corresponding DNA are cut and exchanged between non-sister chromatids of the formed tetrads.
In the fourth step, the nucleus fragments, the nuclear envelope fragments, the two centrosomes (if we're talking about an animal cell) separate from each other as their asters and mitotic spindles (mostly microtubules (kinetochore and non-kinetochore) lengthen. The microtubules extending from the centrosomes can now connect to chromosomes.
Fresh water is any body of water with a low salt concentration. Organisms in fresh water various challenges which includes; Osmotic concentration such that fresh water is permanently dilute and most cells cannot function at this concentration of ions. Varying temperatures, variation in oxygen levels and reproduction and life cycle due to permanence of habitat and physiological difficulty of regulating osmotic concentration in larvae and juveniles.
What? I don’t know what ur saying no offense
<span>for accurate results, for example when they are making vaccines, these are weakened harmful or disease causing viruses,, too little of the virus then it would not be a vaccine or simply would not build you antibodies, and too much of it would not also not a vaccine since it will already inflict a disease or possibly be fatal</span>
Answer:
A Y-chromosome
Explanation:
Males have one X and one Y chromosome
