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.
Nitrogeneous bases
sugar
phosphate group
False, an environment containing no calcium is not the best for Brian shrimp egg hatching. The following evidence statements can be used to support our answer.
- Control shows 9 hatchlings after 72 hours whereas the treatment of 10mg/100ml concentration of calcium shows 17 hatchlings.
- Control shows 9 hatchlings after 72 hours whereas the treatment of 20mg/100ml concentration of calcium shows 28 hatchlings.
- Control shows 9 hatchlings after 72 hours whereas the treatment of 10mg/100ml concentration of calcium shows 39 hatchlings.
