<span>evidence for copper alloy or bronze casting in Sub Saharan Africa.</span>
The correct answers are I and IV
There are three main effects of complement :
1. Lysis of cells such as bacteria and tumor cells.
2. Generation of mediators that participate in inflammation and attract neutrophils to the site of infection, an event called chemotaxis.
3. Opsonization i.e. enhancement of phagocytosis.
Lysis of pathogens by complement involves the insertion of a special substance called the membrane attack complex into the cell membrane of the pathogen which disrupts or punctures the membrane as a result of which water and electrolytes enter the pathogen and it dies.
Generation of mediators known as C5a and C567 complex attract neutrophils.
Answer:
The protein covering of a virus is called a capsid.
I think the enzyme photolyase is activated by light and can repair thymine dimers caused by UV radiation. Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. These enzymes are involved in the repair of ultraviolet light-induced DNA damage when activated by light absorption.
The correct answer is - No.
The Cambrian explosion is a term used for the big and rapid diversification of the animal species, but it is not the period in which the animal life started. The animal life started in the period between 620 and 550 million years ago, in what is known as the Vendian Period. In the Vendian Period, the first complex animal organisms appeared, started to develop and evolve, though it is not a period where there was a high diversification of the species. The later Cambrian Period provided better living conditions, and that resulted in a so called ''explosion of life'', which resulted in much more new species developing and evolving.
