Answer:
Option A, oxygen in the atmosphere
Explanation:
The highest level of oxygen reached during this phase of the geological cycle of earth. The oxygen level in Carboniferous period accounted for 35% as compared to 21% of oxygen in the atmosphere in present time.
Due to high oxygen content, the giant and wide varieties of terrestrial animal and plant species evolved. For example – size of insects and carwlies increased, plant became extremely giant, increase in number of tree ferns etc.
The answer is A. number of pots
The organelle responsible for keeping the cell clean is the cell membrane.
CCUUACUCUUAAG is the mRNA sequence
Answer:
Offspring of a horse and donkey are unable to reproduce.
Explanation:
The biological concept of species states that:
A species is a group of organism with similar characteristics, that can interbreed and have a fertile offspring.
Horse + donkey = mule. A mule is a hybrid and is not fertile.