Euglena, a unicellular freshwater protist, is shown above. Which pair of
lettered organelles likely originated from photosynthetic and aerobic
bacteria?
A)1 and 2
B)3 and 8
C) 5 and 4
D) 7 and 11

Option B is likely originated from photosynthetic bacteria.

Explanation:

A) pellicle and contractile vacoule

B) Stigma and chloroplast (photosynthetic bacteria)

C) reservoir and  flagellum

D) photoreceptor and Nucleolus

Euglena is a genus of single cell flagellate eukaryotes. Euglena have features of both animals and plants. Euglena have photosynthesizing chloroplasts within the body of the cell, which enable them to feed by autotrophy, like plants. Euglena's chloroplasts evolved from a eukaryotic green alga. Thus, the intriguing similarities between Euglena and the plants have arisen of a secondary endosymbiosis. Molecular phylogenetic analysis support this hypothesis but this is not generally accepted. A stigma (red eyespot) is located near the base of the reservoir and this filters the light and focuses it on the paraflagellar body, and is involved in the phototaxis of this alga.

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.