<span>The question is asking us to choose the order of increasing complexity and the correct answer is
(3) organelles → cells → tissues → organs. Organelles are parts of cells, for example a mitochondrium is an organelle. Many cells form tissues and tissues form an organ. Many organ for an organism, for example, a human being is an organism - that's the whole animal or plant. </span>
<span>The stage at which all the cells show crossover chromosomes is meiotic prophase I. The crossover is the exchange of genetic material between homologous chromosomes. Homologous chromosomes are present in the meiosis I. Regarding the phase of meiosis I, it is expected that the crossover takes place in meiotic prophase I since homologous chromosomes pair up in the prophase.</span>
Pythons are affecting everglades very negatively they are causing chaos in the food pyramid attacking all levels and not having predators prey on them pythons have become a huge problem that must be dealt with quickly because their affects are being felt quickly and very largely.
<span>It began with selective breeding in the ancient times where a population with desirable traits were bred with other population to achieve a desired set of traits. It then continued with the advance in the discovery of bacteria (Escherichia coli) and antibiotics. Then Watson and Crick discovered the structure of DNA. The latest advance being that of gene sequencing and gene editing tools. </span>
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