Biology Test - 20

The intestine absorbs the digested food materials. Columnar epithelium cells are responsible for absorption.

• The columnar epithelium is located in the digestive tract in the stomach, large intestine, small intestine, and functions as a barrier to bacteria and other microbes but permits the absorption of digested food.
• Stratified squamous epithelium cells are present in parts of the body where constant abrasion takes place, e.g. the outer layer of skin, the inner lining of the mouth, oesophagus, and vagina.
• Spindle fibers are protein structures that arise from centrioles in a cell during mitosis (functions in a separation of chromatids during cell division).
• Cuboidal epithelium is located in kidney tubules, glandular ducts, ovaries, and the thyroid gland (functions in protection, secretion, and absorption.

Right to Education: Article 21-A, is a Fundamental Right.
Article 21-A declares that "The State shall provide free and compulsory education to all children of the age 6 to 14 years in such a manner as the state may determine."
This provision was added by the 86th Constitutional Amendment Act, 2002. 
In pursuance of Article 21-A, the Parliament enacted the Right of Children to Free and Compulsory Education (RTE) Act, 2009.

'Sparging' is the process in which an inert gas is bubbled through the solvent reservoir to remove dissolved gases. Air sparging, a remediation process in which air is pushed through contaminated water or soil to remove volatile pollutants.

Reptiles have two auricles and a partly divided ventricle except crocodiles which have four chambered heart. Obelia shows metagenesis i.e., alternation of generations which may be defined as a a phenomenon in which diploid asexual phase alternates with haploid sexual phase. Lemur has a the codont teeth i.e., the teeth are embedded in the sockets of the jaw bone.

Humans produce droplets of saliva or mucus in various ways such as sneezing, coughing, speaking, etc. These droplets vary in size. Large droplets (> 5 µm) tend to settle to the ground rapidly. Droplets smaller than 5 µm are referred to as droplet nuclei and may remain suspended in the air for longer periods.

Many common infections can spread by droplet transmission in at least some cases, including Common cold, Diphtheria, Fifth disease (erythema infectiosum), Influenza, Meningitis, Mycoplasma, Mumps, Pertussis (whooping cough), Plague, Rubella, Strep (strep throat, scarlet fever, pneumonia).

So, a and c both are transmitted by droplet infection.

Malaria is a serious and sometimes fatal disease caused by the bite of a mosquito infected with one of four malaria blood parasites from the Plasmodium genus. Infected female mosquitoes are responsible for the spread of human diseases.

Polio is spread when the stool of an infected person is introduced into the mouth of another person through contaminated water or food (fecal-oral transmission). Oral-oral transmission by way of an infected person's saliva may account for some cases.

The genetic codes representing amino acid valine are - GUU, GUC, GUA, GUG.

The genetic code is a set of rules defining how the four-letter code of DNA is translated into the 20-letter code of amino acids, which are the building blocks of proteins. The genetic code is a set of three-letter combinations of nucleotides called codons, each of which corresponds to a specific amino acid or stop signal.

Recent human population growth is attributed to:

• Agricultural revolution
• Industrial revolution
• Medical advances
• Altruistic behaviour

The last 100 years have seen a massive fourfold increase in the population, due to medical advances, lower mortality rates, and an increase in agricultural productivity made possible by the Green Revolution.

Scorpion, spider and cockroach belong to Phylum Arthropoda and are invertebrates. They possess ventral solid central nervous system which consists of a dorsal brain connected with a nerve ring to a double ventral nerve cord.

Deoxyribonucleic acid (DNA) is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth, and reproduction of all known organisms.

• Geneis the basic unit of inheritance.
• Genesare hereditary markers from which derive various characteristics like skin color, height, etc.
• It is theunitof recombination, mutation, and self-reproduction.
• Geneis expressed in genetic expression by transcription of mRNA to produce proteins.