IGCSE Biology Paper-4: Specimen Questions with Answers 87 - 88 of 120

Question number: 87

Essay Question▾

Describe in Detail

What are the three levels of biodiversity?


Edward Wilson first applied Biodiversity word in 1992 to describe the all levels of biological organization. There are three hierarchical levels of biodiversity present.

(i) Genetic biodiversity-It is the diversity in the number of genes and structural changes in chromosomes. For example, each human being is very different from all others.

(ii) Species Diversity- The numbers of species of plants and animals that are present in a region constitutes its species diversity. It can be divided into species evenness and species richness.

(iii) Ecosystem or Community Diversity-It is a global biodiversity. Ecosystem diversity can be defined for a specific geographical region, or a political entity such as a country, a state or a taluka. It is divided into three parts:

a- Alpha Diversity b- Beta Diversity c- gamma Diversity

Image shows types of biodiversity

Image Shows Types of Biodiversity

Image shows three different levels of biodiversity and types of ecosystem biodiversity

Question number: 88

Essay Question▾

Describe in Detail

What is antisense RNA Technology? What are the main applications of this technology?


This technology is used for inhibition of gene expression. The concept behind it is that an antisense nucleic acid sequence base pairs with its complementary sense RNA strand and prevents it from being translated into a protein.

Image shows transcription of antisense strand of DNA

Image Shows Transcription of Antisense Strand of DNA

Image shows transcription of antisense strand of DNA into the sense mRNA strand, which is then translated into a polypeptide

Applications of antisense RNA technology-

  • Such techniques are used in fundamental research
  • It is used for the treatment of genetic disorder or infections
  • Antisense drugs are being researched to treat cancer, HIV, CMV etc.