Biologists believe that eukaryotic cells arose from the endosymbiosis of prokaryotio cells. In this theory, prokaryotic cells (endosymbionts) took up residence inside much larger prokaryotic cells (the hosts). Modern-day mitochondria may be descendants of engulfed, heterotrophic bacteria that eould use oxywen to refeabe energy from onganic molecules through aerobic respiration. These specialised prokaryotes were not digest ed by the hosts, but remained alive inside vacuoles of the host cell, performing the same energy-production processes they had done when they were separate organiama Chloroplasts may be descendants of photosynthetic prokaryotes that could capture the energy of sunlight and use that energy to produce organic molecules from CO, The phylogenetic tree depicted in Figure 7.2 shows these evolutionary scenarios)

a. Which is greater: the proportion of modern-day eukaryotes that have mitochondria, or the proportion of modern-day eukaryotes that have chloroplasts?
b. What does this suggest about the sequence of evolutionary developments leading to mitochondria and chloroplasts? (In other words, which more likely came first: mito- chondria or chloroplasts?)
c. What modern day bacteria are likely to be most similar to the chloroplast ancestor?
d. Protists were formerly classified based primarily on their method of locomotion. Name a cell structure some protists have that enable them to move from place to place that some bacteria species also have. (Hint: By looking ahead to the protists that you will examine in lab, you might get a clue).

For starters I think your question is incomplete at the end, if so, contact me again that I can help you with the rest of the questions, meanwhile I answer the ones that I could interpret and the ones that were correctly written ...

1-As for the first question, it is very difficult to calculate, but I would say that the number of eukaryotes with mitochondrial content is greater, on the other hand it is necessary to clarify that both types of cells ... the eukaryotic mitochondrials and the mitochondrial chloroplasts They need each other to survive in this world.

2-It is more likely that the appearance of chloroplasts occurs first, since they are self-sufficient, and did not need further evolution like mitochondrial eukaryotes to survive.

3-An example is Elysia Chlorotica who was recently born.

4-An example of locomotion is by means of sliding or flagella, this mechanism is one of the most famous when it comes to analyzing bacteria that are prokaryotic cells, this flagellum that is formed by strong proteins is what allows the impulse in the adequate means. It is considered to be a very apt mechanism, and not all bacteria possess it, which is considered an advantage by those that do.

Explanation:

The world of eukaryotic and prokaryotic cells is very wide, but its main characteristic that the differences is that an organelle and nucleus presentation

(eukaryote) and prokaryotes do not have various structures ...

Within the eukaryotes we have a subdivision that is chloroplasts and mitochondrials, chloroplasts are in charge of forming the chlorophyll that develops in the world of plants and vegetations, thanks to its mitochondria with perfect self-sufficiency mechanisms for plants. photosynthesis and they don't feed on food like we do.

On the other hand, mitochondrial eukaryotic cells present a genetic load in their mitochondria that is what unites us with our oldest ancestors, calling mitochondrial DNA, it is very important for what you know in other topics such as human evolution.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.