The fossil record shows a sequence from simple bacteria to more complicated organisms through time, it is very reliable because it is physical evidence and by studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.
The answers are A) ectoderm and B) endoderm.
Fertilization is a fusion of male and female gametes which leads to the formation of a zygote. The zygote undergoes mitosis and transforms into a single-layered blastula. Gastrulation is a transformation of the blastula into a two-layer or three-layer gastrula. Cnidarians are a diploblastic animal because their gastrula has only two layers - endoderm and ectoderm.
1 - A ground level plant develops curling tendrils that wrap around other objects so it can "climb".
This is a species changing over time as it was originally a ground level plant but began to climb higher.
2 - Over many generations.
This is because diversity takes time and has to be integrated through generations; for instance, marriage. In a family, it becomes more diverse after the next generation as each generation is likely to marry someone of another ethnicity and allow the family tree to become more diverse.
3 - Mutate or Survive
It depends on what it means by mutate - develop a mutation to make it adaptable? If that's the case, then mutations within the DNA would be a result of adaptation and increase survival. Otherwise, survive is the obvious answer as adaption allows for species to move around and live longer.
Hope this helps!
