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Blology/Exam 4 For each of the following, write on the blank line the letter of the completes the statement or answers the question. word or phrase Biology A DNA nucleotide does not contain (A) adenine (B) thymine. (C) uracil. (D) cy Human blood type is determined by Stadent t 12. A 23. (A) codominant alleles. codominant alleles. (B) a dominant allele. (C) multiple alleles.(D) sex-linked genes 13 People who carry genetic disorders (ca 14A method to trace the inheritance of a trait over many generations is 15The insertion or deletion of a single base pair of DNA results in a (carriers) are 24. (A) heterozygous. (B) homozygous. (C) polygenic. (D) haploid 25. (A) carrier tree. (B) pedigree. (C) phenotype. (D) genotype. 26. (B) nonsense mutation. (D) frameshift mutation. (A) missense mutation. (C) duplication mutation. Gregor Mendel called the generation created by crossbreeding the generation the (A) second parental generation. (C) second filial generation 2 16, (B) cross filial generation. (D) first filial generation. 17. A recessive trait is expressed only in an individual who is 18. A tall pea plant (TT) and a tall pea plant (T) have the same 19The failure of homologous chromosomes to separate properly during meiosis (A) heterozygous. (B) homozygous. (C) haploid. (D) polygenic. (A) alleles. (B) phenotype. (C) genotype. (D) filial type. is called (A) nondisjunction. (B) disjunction. (C) zygote failure. (D) telomere fii 20.- Watson and Crick's model of DNA replication is called (A) conservative. (B) semiconservative. C) transcription. (D) translation. 2. Pea plants usually reproduce by (A) self-pollination. (B) cross-pollination. (C) test-crossing. (D) coning 22. The pairs of alleles in an organism's genetic makeup are called its (A) phenotype. (B) genotype. (C) parental type. (D) filial type.

Answer 1

11. C) Uracil.

DNA contains adenine, guanine, cytosine and thymine. Uracil only present in RNA at the place of thymine.

12. A) codominant alleles.

Human blood contains three different types of alleles-IA, IB and I. IA and IB are codominant.

13. A) heterozygous.

Carriers are recessive because they contain both wild type and the mutant allele (heterozygous). If homozygous for the mutant allele then disease occured.

14. B) pedigree.

Pedigree is a kind of flowchart which describes the family history by considering a particular disease and by analysing pedigree one can trace how the disease is inherited.

15. D) frameshift mutation.

Insertion or deletion of a single nucleotide base changes the whole frame of DNA and of mRNA by one nucleotide from which protein synthesis occurs.

16. D) first filial generation.

First filial generation or F1 generation is generated by the crossbreeding of parental generation.

17. B) homozygous.

Because only in homozygous (individual with two same allele) condition, a recessive trait is expressed. If one is dominant and one is recessive allele (e.g. Tt), dominant phenotype expressed. Recessive phenotype expresses only if there are two recessive allele (e.g tt).

18. B) phenotype.

Phenotype is the physical appearance based on genetic constituents. Here both are tall.

19. A) nondisjunction.

Homologous chromosome is a set of a paternal and a maternal chromosome. To seperate sister chromatids properly in meiosis-II it is required to seperate homologous chromosomes in meiosis-I. If there is a problem in seperation of these two chromosome, nondisjunction occurs. E.g trisomy.

20. B) semiconservative.

Because after generation of two new DNA from a single DNA, each of the daughter DNA contains a parental strand and a de novo strand. So half of the DNA is conserved hence semiconservative.

21. A) self-pollination.

Pea plants are hermaphrodite that is it contains both female and male parts. So it itself contains all the parts for reproduction.

22. B) genotype.

Genotype is the genetic constituent of an organism that determines the phenotype. A pair of allele like tt or Tt is called as the genotype