Answered

which of the following statements describes the central dogma of molecular biology?
A.Biological information in a cell passes from DNAto RNA to protiens
B.Biological information in a cell passes from RNA to protiens to DNA
C.Biological information in a cell passes from RNA to DNA to protiens
D.Biological information in a cell passes from protien to RNA to DNA

how many chromosomes are shown in a normal human karyotype?
A.2
B.23
C.44
D.46
Which of the following has the disadvantage of possibly bringing two ressesive alleles together and causeing a genetic defect?
A.inbreeding
B.hybridization
C.genetic engineering
D.transformation



Answer :

Q1. The answer is A.Biological information in a cell passes from DNAto RNA to proteins. The biological information is the part of DNA. During transcription, DNA is transcribed into RNA which now serves as a template for the synthesis of proteins. Thus, the central dogma of molecular biology describes how biological information in a cell passes from DNA to RNA to proteins.
     
Q2. The answer is D. 46. In a human diploid somatic cell (2n), there are 23 chromosomes present in two copies - 22 pairs of autosomes and 1 pair of sex chromosomes. So, in a normal human karyotype there will be in total 46 chromosomes (23 pairs in 2 copies: 23 × 2 = 46).
   
Q3. The answer is A. inbreeding. Inbreeding is a breed from closely related organisms. Inbreeding causes a decrease of genetic variation by increasing homozygosity. This way, it can cause the genetic defect by bringing two recessive alleles together.