a reaction where particular set of chemicals changes into another form without changing their nuclei just the transfer or sharing of electrons and formation and breaking of bonds is called as chemical reaction.
example- formation of water, photosynthesis etc.
but if there is a change in nuclei than it would be called as nuclear reaction.
like Uranium breakdown etc.
Answer:
Cell divison is defined as the process in which a parent cell split into two or more daughter cells. There are three stages of cell division that includes interphase, mitosis/meiosis and cytokinesis.
In the interphase the proteins, enzymes and cell organelles are formed and at the end of this phase single strand chromosome becomes a double strand carrying genes.
In the meiosis (in sexual reproduction) or mitosis (asexual reproduction) phase, divison of nucleus takes place. Meiosis gives rise to geneticaly different cells due to crossing over while mitosis leads to identical cells .
Cytokinesis occurs cocurrently after meiosis or mitosis in which cytoplasm of a parental cell divides into two daughter cells each with identical chromatin.
Creation of new animals are also undergo these 3 stages of cell division that is interphase, meiosis (eukaryotes)/mitosis (prokaryotes) and cytokinesis. Majority of animals (eukaryotes) undergo meiosis phase because their mode of reproduction sexual and have genetic variation due to crossing over of chromosomes and produces 4 daughter cells at the end cell division.
Hence, the 3 stages of cell division is similar to craetion of new animals.
Its autotrophs, they are the first level of the food pyrimid
Answer: During the Cambrian Explosion of Animal Life