Label or a placard colored black and white with a skull and crossbones falls under which class

The correct answer is class-6 toxic and infectious components.

Explanation:

A placard or a label colored black and white with a skull and crossbones comes under class-6 health hazards. The class-6 is further sub differential into two categories, that is, class 6.1 and class 6.2.  

Class 6.1 signifies toxic substances, which possess the tendencies to cause serious injury or death or harm human health is inhaled or swallowed or coming in contact with skin.  

Class 6.2 comprises infectious substances, which are anticipated to constitute pathogens. The pathogens are illustrated as microbes that can result in diseases in animals or humans.  

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.