Answer: The question is not complete as options are not complete , the remain part are;
A. 3.7 years, photosynthetic bacteria.
B. 3.7 years cyanobacteria.
The correct option is
3.7 billion years old, cyanobacteria and stromatolite.
Explanation:
This is because cyanobacteria is the oldest fossil to exist and they have been in existence for about 3. 7 billion years. These cyanobacteria photosynthesized because they have thread like chlorophyll filament, they produce food through the process of photosynthesis which is needed for their survival and they release oxygen as bye product.
Lancelet is a chordate but not a vertebrate because it lacks a backbone
Explanation:
The subphyla of the phylum Chordata are - Vertebrata, Urochordata and cephalochordate
Those chordates with a structural backbone belong to Vertebrata.
Urochordates and cephalochordates lack a backbone and hence are termed invertebrate chordates.
Lancelet is an invertebrate chordate of the subphylum – Cephalochordata.
The lancelets consist of a notochord that extends right from the head till the tail at the dorsal surface. The notochord acts like the backbone and provides support and a semi-flexible structure to aid in the movement of the organism.
They lack a developed nervous system like vertebrates but only has a dorsal nerve tube
.
The most likely reason is because of the decrease of population of prey in the south
Carbohidratos termina en s
Number of producer depends on ecosystem we are talking about. I am taking this question as terrestrial ecosystem so for the terrestrial ecosystem the answer will be group D.
In terrestrial ecosystem number of producer is higher than the second trophic level that is primary consumer. To study this we use pyramid of number. In most cases the pyramid of number is upright with members of successive higher trophic level being fewer than the previous one. The maximum number of individuals occurs at the producer level.