The answer is "D"
The body's first line of defense is also known as Innate immunity and incudes mucous membranes. Both the intact skin and mucous membranes of the body offer a high degree of protection against pathogens.
A good example is the mucous membrane of the respiratory tract. It is lined up with cilia and covered with mucus. The coordinated beating of the cilia drives the mucus up to the nose and mouth where the trapped bacteria can be expelled.
(Lymph nodes and white blood cells belong to the second line of defense, not the first)
Answer:
Photosynthetic lamellae
Explanation:
The cyanobacteria were the first successful photosynthetic cells present on the Earth which were able to convert the light energy into the chemical energy.
The endosymbiosis theory suggested that these cyanobacteria were engulfed by the eukaryotes and the cyanobacteria get transformed into the chloroplast.
The region of the chloroplast that was formed in the cyanobacteria before the endosymbiosis happened was the photosynthetic lamellae which contained the chlorophyll molecule and thus is the correct answer.
Thus, Photosynthetic lamellae are the correct answer.
Answer:
nuclear fusion
Explanation:
When the density and temperature at the core of the gravitationally collapsing nebula reaches values when nuclear fusion is triggered and sustained, that marks the birth of the star.
Answer: The correct option is D(Some produce toxic agents in the water).
Explanation:
Dinoflagellates are found in the phylum Dinoflagellata which are single celled organisms. They are mostly found in the ocean while few of them can live in streams, freshwater ponds and rivers. The following characteristics can be used to identify a Dinoflagellates, these include:
--> they are golden brown
--> they possess assimilative cell with indented waist.
--> they possess large nucleus with visible chromosomes.
It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Therefore the option, Some produce toxic agents in the water, is a correct statement.
