Answer:
d) polyps; calcium carbonate
Explanation:
The Acanthaster planci It is a kind of invasive starfish, which destroys corals: it has poisonous spines and feeds on coral polyps at the expense of the reef.
On the other hand, CO2 reacts with water, forming carbonic acid and reducing the available calcium carbonate, an essential element so that marine organisms, from clams to hedgehogs, can form their skeletons and shells.
I would say leaf cuz they also have different layers :)
Plz give brainiest if I am right
Good luck
Answer: The correct answer is- D certain factors are dominant and other factors are recessive.
Mendel was interested in knowing the offspring that is produced from the cross pollination (that is from two different plants) as he wanted to study different traits of pea plant.
For doing so, he first removed the anthers of one plant (to prevent self pollination) and then transferred the pollens of one plant into the stigma of another plant.
When he allowed the cross pollination of purebred pea plant with other plant, he observed that some factors are dominant (such as tall height of pea plant, which masks the expression of recessive factors) and other are recessive (such as dwarf height of pea plant).
Thus, option D) is the right answer.