Answer:
The correct answer is - DNA tightly coils around proteins and condenses into chromosomes, which fit in the nucleus.
Explanation:
The chromatin reticulum is present in the undivided cells, which condenses to form a rod-like form called a chromosome. The chromosome consists of DNA structures.
That DNA is a double helical structure and acidic in nature and it is present inside the chromosomes as it is coiled around histone protein which is basic in nature. That allows the DNA to fits in the nucleus.
Thus, the 3rd statement is the correct answer.
Answer:
When do new species develop?
New species develop after fertilization has occurred which brought about a new organism or specie callled a zygote. Such new species inherit traits from parents
Explanation:
The question is incomplete. The complete question is:
Question: Innate immunity:
a) is based on recognition of antigens that are specific to a pathogen.
b) is the first and most general, mechanism of protection against pathogens
c) is found only in vertebrates
d) depends on an infected animal's previous exposure to a pathogen
Answer:
b) is the first and most general, mechanism of protection against pathogens
Explanation:
Innate immunity is the nonspecific immune response that provides immediate and the most general protection against all types of pathogens, parasites, toxins and cancer cells. Innate immune responses serve to prevent the pathogens from entering the body. The components of innate immunity also rapidly destroy those pathogens that have entered the body.
Some of the components of innate immunity are the first line of defense such as the physical and chemical barriers of the skin and mucous membranes. The components of the second line of defense such as natural killer cells, phagocytes and inflammatory response are also involved in innate immune responses.
For example, cuticle or skin serves as a physical barrier to pathogens that come in contact with an animal’s body. Phagocytosis kills the bacteria that invade the body.
Treatment
Meningitis is an infection of the membranes, meninges that surrounds and protects the central nervous system (the brain and spinal cord). Bacterial meningitis must be treated immediately with intravenous antibiotics and sometimes corticosteroids and, of course, the antibiotic depends on the type of bacteria causing the infection.
Prevention
First of all, to prevent the spread of bacterial meningitis it is important to practice good hygiene, such as frequent handwashing. Since the factors that increase the risk include spending time in communities (school, campus or college) because it spreads easily, children should be aware and vaccinated. As several types of bacteria can cause bacterial meningitis, a range of vaccines is wide (e.g. meningococcal vaccine, Hib vaccine).
The answer is D. Dissolution
