1. Which of the following best describes a homozygous genotype?

 a) An organism with two different alleles for a trait. 

 b) An organism with two identical alleles for a trait. 

 c) The physical expression of a trait. 

 d) The allele that is masked in the presence of another allele.

2.  In a monohybrid cross between two heterozygous (Tt) tall pea plants, what is the expected phenotypic ratio of the offspring?

 a) 3 tall: 1 short 

 b) 1 tall: 1 short 

 c) 3 short: 1 tall 

 d) 4 tall: 0 short

3. Which of the following processes increases genetic variation in sexually reproducing organisms?

 a) Mitosis 

 b) Binary fission 

 c) Independent assortment 

 d) Cloning

4. (2 marks) What is the function of messenger RNA (mRNA) in protein synthesis?

 a) To carry genetic information from DNA to the ribosome 

 b) To transport amino acids to the ribosome 

 c) To catalyze the formation of peptide bonds 

 d) To maintain the structure of the ribosome

5. (2 marks) Which of the following genetic disorders is caused by a recessive allele?

 a) Huntington's disease 

 b) Cystic fibrosis 

 c) Marfan syndrome 

 d) Down syndrome

6. (2 marks) If a man with blood type A and a woman with blood type B have a child with blood type O, what are the possible genotypes of the parents?

 a) AA and BB 

 b) AO and BO 

 c) AB and OO 

 d) OO and AB

7. (2 marks) A color-blind man marries a woman who is a carrier for color blindness. What is the probability that their son will be color-blind?

 a) 0% 

 b) 25% 

 c) 50% 

 d) 100%

8. (2 marks) Which of the following describes the phenomenon where a single gene influences multiple phenotypic traits?

 a) Epistasis 

 b) Pleiotropy 

 c) Codominance 

 d) Polygenic inheritance

9. (2 marks) In a dihybrid cross, what phenotypic ratio is expected in the F2 generation if both parents are heterozygous for both traits?

 a) 9:3:3:1 

 b) 3:1 

 c) 1:1 

 d) 1:2:1

10. (2 marks) Which of the following statements is true about the genetic code?

 a) It is ambiguous, meaning that a single codon can code for multiple amino acids. 

 b) It is universal, meaning that nearly all organisms use the same codons for the same amino acids. 

 c) It is completely different for prokaryotes and eukaryotes. 

 d) It does not include stop codons.