Question 1:
<u>Answer</u>:
The "first line of defence" in innate immunity is "Physical and chemical barriers".
<u>Explanation</u>
"Physical and chemical barriers" is first line of defence includes that are ready to defend the living organism's body from infection at any time . These barriers include your skin, cilia, tears, urine flow, mucus, stomach acid, friendly bacteria and white blood cells . Skin acts as a mechanical barrier as it does not allows all the organism to pass through it unless the skin is cut or open. Similarly mouth eyes, and nose are also the ways through with the disease causing organism can enter the body. The micro-organisms that entered through these pathways are trapped either in saliva or mucus and swallowed and later either killed in the stomach or flushed out via the urine. If this first line of defence is broken or damaged, the second line of defence inside our body will be activated.
Question 2:
<u>Answer:</u>
Histamine kinins, and interleukins are examples of inflammatory mediators.
<u>Explanation</u>:
Inflammatory mediators are identified in inflammatory bowel disease IBD.These mediators play an vital role in the clinical and pathologic characteristics of the disorders. Cytokines, that are released by macrophages in due to antigenic stimuli, are binded different receptors and produce endocrine, autocrine and paracrine effects. Interleukins are a subset of a large group of 'cellular messenger molecules' called cytokines that modulates the cellular behaviour. Interleukins are not stored within cells like cytokines but they are released immediately, in response to a stimulus. Once an interleukin has been secreted, it moves to the target cell and binds to it through a receptor molecule on the surface of the cell . This interaction triggers a sequence of signals in the target cell that ultimately leads to the alteration in the behaviour of the cell.
Answer:
<u>3) Uncontrolled cell division occurred as a result of gene mutations</u>
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Explanation:
Spontaneous modifications within the genome may occur during the process of cell division. When copies of the DNA inside the cell are made, these mutations cause errors; and can include small single nucleotide polymorphisms, and large scale additions or deletions across multiple genes.
Some, like somatic mutations, exist only inside vegetative (body) cells, that cannot be passed onto offspring. This is caused by several factors like
- UV radiation,
- chemical mutagens,
- infective agents
UV radiation damages strands of DNA, by causing dimers to form; here, consecutive nucleotide bases covalently bond instead of those on the complementary strand. This conformational change causes errors in DNA proofreading and repair mechanisms where bases are not well-incorporated into the strand- tumors (clumps of uncontrolled cell growth) may form, resulting in melanoma, a type of skin cancer.
Only toms idea could be scientific since it is testable, can be tested by others, have a hypothesis, and be proven
The diffusion of water through a cell membrane to reach dynamic equilibrium.
Answer:
tissues that is responsible for the secondary growth of stems and roots.
