During the S phase in the cell cycle, the chromosomes are replicated so that there are two copies. These copies are necessary so that each daughter cell created during the M phase will have an identical copy of the DNA.
Therefore, the answer is A: The DNA must be replicated.
The chromosomes joining, cell membrane expanding, and cytoplasm separating all happen during the M phase (mitosis).
Birds and reptiles lay amniotic eggs. They consist of a shell, embryonic membranes, and the embryo.
Answer: Y represents carbon and z is oxygen which gives CO2
Explanation: To photosynthesis to occur Carbon has to reacts with oxygen to give carbondioxide (Co2) which then combines with hydrogen (H2) and oxygen to give water (H20) the reaction gives glucose (C6H12O6).
Equation for photosynthesis = 6CO2+6H20- C6H12O6
The carry the deoxygenated blood from the heart to the lungs and Pulmonary veins do the opposite!
