Correct answer - Tetrahedral, planar or flat.
Why? - When carbon forms single bonds with other atoms, the shape is tetrahedral. When two carbon atoms form a double bond, the shape is planar, or flat. Single bonds, like those found in ethane, are able to rotate.
Natrual variations i think
I think I understand even without the picture. I'll add a picture of the Punnett Square filled in, but what you're crossing is
Tt x tt (heterozygous crossed with a homozygous recessive)
The ratio you get in the end is 2 heterozygous (Tt) and 2 homozygous (tt) offspring, so the ratio is 1:1.
So the percentage of offspring that are homozygous recessive is 50%.
Assuming you mean living matter
All living matter is produced by other living matter
The fossil record
This supports Darwin's theory of evolution, which states that simple life forms gradually evolved into more complex ones. Evidence for early forms of life comes from fossils. By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. What traces there were may have been destroyed by geological activity. This is why scientists cannot be certain about how life began.
Fossils provide a snap shot of the past and allow us to study how much or how little organisms have changed as life developed on Earth.
