We label the human sex chromosomes with X's and Y's. For example. A boy's chromosomes are XY. A girls chromosomes are XX. When a child is born, they get an X from their mother, and either an X or Y from their Father, thus determining their sex.
I think the hydra lacks the specialized cells for touch and chemical detection. On the other hand earthworms have touch, light, vibration and chemical receptors along the entire body surface. Both of them are invertebrates (those animals without a backbone), they include insects, worms, jelly fish, spiders among other animals.
A scientist can study <span>the relationship between the Tiktaalik roseae and modern fish and tetrapods by creating </span>a diagram that hypothesizes ancestry relying on the fact that common descent<span> describes how, in </span>evolutionary biology<span>, a group of </span>organisms<span> share a </span>most recent common ancestor<span>.</span>
Answer:
The first living organism on Earth are Bacteria in the first era.
Explanation:
Bacteria are the first organism to leave be on Earth. They came into existence about 3.5 billion years in the first era in the waters of small oceans. Then there were anaerobic hetetrophic bacteria because the atmosphere was free of oxygen before. Cyanobacteria then became the first autotrophic organisms and first photosynthesizer that release oxygen to the atmosphere after photosynthesis.
I think it's Genetic engineering