Answer:a. Retention of five functional digits on the tore and hindimbs
Explanation:
The presence of five digits or pentadactyly on the fingers as well as on the toes makes the primates distinct from other mammals. Also the keratin nails are present on each digit makes these organisms distinct from other mammals.
The five digits on the hindlimbs helps in grip of objects and on toes helps in climbing.
Answer:
(C) Aminoacyl-tRNA synthetases have an additional active site that binds to non-cognate tRNAs. The tRNAs that bind to this second active are hydrolyzed and released from the enzyme.
Explanation:
In case of translation, proof reading is done by aminoacyl-tRNA synthetases only. Aminoacyl-tRNA synthetases have two mechanisms to avoid error during translation which are mentioned as under:
<u>(1) Chemical proof reading:</u> Incorrect amino acids rather than being hydrolyzed in catalytic pocket get hydrolyzed in editing pocket and thus they hardly get attached to tRNA.
For example: For distinguishing similar amino acids like isoleucine and valine, isoleucyl-tRNA synthetase uses a second active site which is meant for only valine not for isoleucine. In this particular site, valine which had entered the enzyme is cleaved away with the help of editing reaction after which the enzyme is well prepared to process isoleucine which is the correct amino acid for this enzyme.
<u>(2) Kinetic proof reading: </u>Even if an incorrect amino acid has entered a particular aminoacyl-tRNA synthetase, it does not cause appropriate conformational change in the enzyme because of which the incorrect amino acid loosens from the enzyme and does not get incorporated.
Note: In this example, only chemical proof reading is mentioned not kinetic proof reading.
Answer:
DNA can be described as the molecules which carries the genetic code for every individual. The DNA is made up of nucleotide bases which join the two strands of DNA. The sugar and phosphate form the backbone of the DNA.
Genes are the hereditary molecules which are made up of DNA. The alleles of a gene represent which traits will be carried by an organism.
Chromosomes are made up of genes. During reproduction, crossing over of DNA occurs and alleles of the genes assort independently due to which variations occur.
Bacteria in our gut help to protect us by crowding out some of their dangerous relatives that can cause disease. Other good bacteria have been used in medicine to create antibiotics, and others still are used in food production to make fermented foods (think sauerkraut, yogurt, kimchi and kombucha.)
Answer:
We breath in then out through our lungs
Explanation:
