An organism is said to be ( ) if it carries two identical alleles for a certain trait. A: heterozygous B: homologous C: homozygous D: monohybrid E: dihybrid

The characteristics of diet in Tang Dynasty are ( ). A: south sweet, north salty B: drug homologous food C: diet can reflect politics

Which of the followings would contain genetic material that is 100% identical? A: Homologous chromosomes B: Sister chromatids C: X and Y chromosomes D: Acrocentric chromosomes E: non-sister chromatids

The<br/>integration mechanism of foreign genes in genetically modified crops<br/>are () A: Homologous<br/>recombination B: Site-specific<br/>recombination C: Transposition<br/>recombination D: Heterologous<br/>recombination

By definition, homologous genes are genes that: A: Share a common function. B: Share a common evolutionary ancestor. C: Are expressed under similar conditions. D: Have at least 50% nucleotide sequence identity.

Which of the following does not lead to the formation of aneuploid gametes? A: Failure of homologous pairs to separate at anaphase B: A mutatation in a single gene located on chromosome 2. C: A pair of sex chromosomes that does not separate during anaphase D: A set of sister chromotids that doest not separate during anaphase I

There was only one peak in the epidemic curve of a disease, and all<br/>cases are concentrated in the common incubation period of the<br/>disease, then the disease transmission mode maybe ( ). A: both<br/>homologous and continuous B: common source epidemic C: mixed type D: human to human E: unable to judge

Which of the following is not the diagnostic basis for suspected COVID-19 cases？ A: Epidemiological history B: Fever and / or respiratory symptoms C: Viral genetic sequencing is highly homologous to that of known SARS-CoV-2 D: In the early stage of, the total number of white blood cells is normal or decreases, and so is or does lymphocyte count. E: With the imaging characteristics of COVID-19.