Beacuse they died long time ago
Answer:
Organisms that are more complex, such as eukaryotes, have cells that are specialized for specific functions. Gene regulation needs to be more complex to produce these specialized cells for complex organisms. Please Mark Me Brainliest
Explanation:
////////////No///////////
Glucose is the main provider of energy for the brain and the nervous system. Because the brain is so rich in nerve cells, or neurons, it is the most energy demanding organ, using one half of all the sugar energy in the body. Brain functions such as memory, thinking and learning are closely linked to glucose levels and how efficiently the brain uses this fuel source.
Answer:
Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Some examples include height, skin color, eye color and weight.
- In polygenic inheritance the "dominant" capital genes are additive, each capital gene adding one unit of color to the genotype.With more capital genes, the phenotype (appearance) gets darker.