A good index fossil is one with four characteristics: it is distinctive, widespread, abundant, and limited in geologic time. Because most fossil-bearing rocks formed in the ocean, the major index fossils are marine organisms
Make sure you post the picture of the tree, so I can answer.
***see attached pic***
Some helpful tips:
The nucleus is always going to be the big, spherical shape.
The ER is always going to be a weird, folded looking structure attached to the nucleus (rough = has ribosomes on it which are usually represented by little dots, smooth = has no ribosomes on it aka no dots)
The GA looks like the ER but it is not going to be attached to the nucleus like the ER is.
The mitochondria is always going to be pill-shaped and have weird folds inside of it.
Answer:
Spore can survive under unfavorable conditions as they are covered by a hard protective coat. Spores can grow to produce new plants and does not require sexual interaction with another organism. Due to their small size and light weight, they can be dispersed easily.
Spores can remain dormant till favourable conditions become available. b. Spores help an organism to tide over the bad phase. Spores can be spread through water, air or animals and thus is good for the spread of an organism to more places.
Explanation: hope this helps bro! (:
