Answer:
a/1 chloroplast
Explanation:
chloroplasts hold green pigment
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Answer:</h2>
Option A. Bacteria.
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Explanation:</h2>
- It is presumed that, over millions of years of evolution, abiotic molecules evolved into the self-replicating molecules by means of natural selection.
- Cyanobacteria, or blue-green algae is a bacteria which was one of the oldest fossils found on earth. These microbes conduct photosynthesis: using sun light, water and carbon dioxide to produce carbohydrates and oxygen.
- Cynobacteria played a major role in forming oxygenated atmosphere.
- The first living things on the planet Earths was single-celled micro-organisms which lack a well defined cell nucleus were known as prokaryotes, and bacteria belongs to prokaryotes ans hence among given options bacteria matches the most for the first life form on earth.
Result: Among the given choices bacteria was most similar to first living things on earth.
The answer is: Plasma.
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Answer:
The reason why cities tended to develop in the region of the fall line of rivers is because of the need to offload goods from the ships since navigation will be hindered at the zone.
Explanation:
Fall line is a region that separates the upland or mountainous zone from the lowland river bodies, where waterfall also occurs. The waterfall in this region tends to expose the beneath bedrock materials and stop the movement of riverboats and ships upstream. Therefore, the boats must offload their goods, which tends to induce the formation of ports and majorly settlement by commercially oriented people who are willing to utilize the opportunity to trade on the commodities offloaded. The emergence of cities along the river fall lines is owing to this reason.
Answer:
In general, your body fights disease by keeping things out of your body that are foreign. Your primary defense against pathogenic germs are physical barriers like your skin. You also produce pathogen-destroying chemicals, like lysozyme, found on parts of your body without skin, including your tears and mucus membranes. In response to infection, your immune system springs into action. White blood cells, antibodies, and other mechanisms go to work to rid your body of the foreign invader. The immune system has a vital role: It protects your body from harmful substances, germs and cell changes that could make you ill. It is made up of various organs, cells and proteins.
Once infected cells have sensed an invading pathogen, they secrete molecules called cytokines and chemokines. These cells are then primed to resist an infection with the invading virus. Cytokines such as interferons activate anti-viral genes in the infected and neighbouring cells.
Microorganisms capable of causing disease—or pathogens—usually enter our bodies through the eyes, mouth, nose, or urogenital openings, or through wounds or bites that breach the skin barrier. Organisms can spread, or be transmitted, by several routes.
The second line of defense is nonspecific resistance that destroys invaders in a generalized way without targeting specific individuals: Phagocytic cells ingest and destroy all microbes that pass into body tissues. For example macrophages are cells derived from monocytes (a type of white blood cell).
If pathogens do manage to enter the body, the body's second line of defense attacks them. The second line of defense includes inflammation, phagocytosis, and fever.