The ice has less density than liquid water, so it floats on the water surface. Therefore during the winter all the lakes and rivers are frozen only at a top. Deeper layers of water are cold, but still liquid and it allows fish and other organisms to survive. Moreover, the ice cover provides temperature isolation so liquid water beneath the ice has more or less constant temperature (around 4 dgr Celsius)
The sequence that correctly describes the route that an egg takes through the female reproductive system would be option d. Ovary - Fallopian tube - Uterus. The mature egg is released by the ovary into the Fallopian Tube. Once it is fertilized, it is embedded in the wall of the uterus and this is where the unborn baby develops. If fertilization does not happen, the endometrium is broken down, which results in menstruation.
Atoms may have different numbers of neutrons. Atoms are the smallest fraction of an element that can exist, and still show the properties of the element. They consists of electrons (negatively charged), protons (positively charged), and neutrons (no charge). The number of electrons is equivalent to the number of protons normally however an atom may loose or pick up electrons and have a positive charge or negative charge. The number of neutrons in the nucleus may vary within a given element to give varieties of atoms we call isotopes.
Eukaryotic cells posses a nucleus the purpose of the nucleus is it stores DNA which is the genetic material for the cell DNA acts as an instruction manual for the other organelles in the cell. While prokaryotic cells do not have a nucleus they still have dna but it’s floating around freely
