This is because it has many parts, arteries, and tubes that pass blood around the body. It is hard because it has many parts which are difficult to be cut open. Hope I helped!
Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads, and exchange DNA. The nucleolus and nuclear envelope disappear.
Answer:
The purpose of the siphon is to drain liquid from the reservoir by liquid flow that passes over a higher level than the liquid surface in the reservoir.
The formation of the fertilization envelope requires an increase in the cytosolic concentration of calcium ion .
<h3>What is fertilization?</h3>
The process of union of a haploid male gamete or sperm with a haploid female gamete or ovum to form a diploid cell ,zygote ,is called fertilization .
In human fertilization is internal as it takes place in the fallopian tube .
During coitus male discharge sperm to the vagina of the female , from the vagina sperm reach the ampulla partly by the movement of their tails and partly by the action of uterus .
After completing this long travels sperm reaches the fallopian tube within five minutes .
Learn more about fertilization here:
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