Question

referred to the trait that was expressed in the hybrid, F, or first filial generation, as A. recessive B. codominant C. dominant D. epistatic 62. When the two haploid gametes contain two different alleles of a given gene, the resulting offspring is called A. discrete B. heterozygous C. a haploid D. homozygous 63. An allele that is present but unexpressed is A. redundant B. functional C. dominant D. recessive 64. The classes of RNA molecules made in cells include all of the following except A. mRNA B. rRNA C. tRNA D. cRNA 65. Ribosomes are complex arrangements of A. RNA and DNA B. RNA and sugars C. RNA and large proteins D. DNA and proteins ali a ne 66. In eukaryotic cells, mRNA is made as a copy of the DNA in the A. cytoplasm B. nucleus C. mitochondria D plasma membrane 67. In human males, genes on the X chromosome are C. homozygous A. hemizygous B. heterozygous 68. During replication, the role of DNA primase is to A. add nucleotides to the growing DNA chain B. untwist the double helix at the origin of replication C. synthesize a short chain of RNA D. relax the supercoiling of the double helix 69. Okazaki fragments are made from which strand of the DNA double helix? A. leading B. conservative C. continuous D. lagging 70. Which enzyme prevents DNA from tangling up as the replication fork migrates during replication? A. DNA helicase B. DNA polymerase I C. DNA polymerase III D. DNA gyrase

Answer 1

Ans-61

One allele known as dominant allele other one known as recessive allele of same gene. When cross is done then in first filial generation or F1 generation only dominant allele is expressed. Recessive one is expressd when they are in homozygous state.

So C option is correct

Ans-62

If offspring consist of same alleles of a gene then it is known as homozygous while different allele are present of same gene in offspring known as heterozygous

So B option is correct

Ans-63

When one recessive allele is present then it is an unexpressed but recessive alleles are in homozygous then it is expressed.

So option D is correct

Ans-64

a) m-RNA is formed during transcription from DNA so incorrect

b) r-RNA is formed in nucleolus and associate to ribosome so incorrect

c) t-RNA is formed in nucleus by RNA polymerase III and after splicing or removing introns which then goes to cytoplasm and support translation.

d) complementary(c) RNA not formed in cell it is synthetic RNA which is formed outside by transcription of single strand of DNA

So D option is correct