Human Development and Genetics MCQs

1. : Which of the following is the first stage of human embryonic development?
(A) Blastula
(B) Zygote
(C) Morula
(D) Gastrula

2. : What is the term for the process by which a single zygote develops into a multicellular organism?
(A) Fertilization
(B) Cleavage
(C) Morphogenesis
(D) Differentiation

3. : During which stage of embryonic development do the three germ layers form?
(A) Blastulation
(B) Gastrulation
(C) Neurulation
(D) Organogenesis

4. : Which genetic condition is caused by the presence of an extra chromosome 21?
(A) Turner Syndrome
(B) Klinefelter Syndrome
(C) Down Syndrome
(D) Patau Syndrome

5. : What is the term for the genetic phenomenon where two different alleles for a trait are expressed simultaneously?
(A) Codominance
(B) Incomplete dominance
(C) Complete dominance
(D) Epistasis

6. : Which process involves the exchange of genetic material between homologous chromosomes during meiosis?
(A) Independent assortment
(B) Crossing over
(C) Mutation
(D) Gene flow

7. : In Mendelian genetics, what is the expected phenotypic ratio of a monohybrid cross between two heterozygous individuals?
(A) 1:1
(B) 3:1
(C) 1:2:1
(D) 9:3:3:1

8. : Which term describes a genetic trait that is expressed only when two copies of the gene are present?
(A) Dominant
(B) Recessive
(C) Codominant
(D) Incomplete

9. : What is the primary purpose of mitosis in human development?
(A) Formation of gametes
(B) Reduction of chromosome number
(C) Growth and repair of tissues
(D) Genetic recombination

10. : Which genetic disorder is characterized by a single gene mutation affecting the production of the enzyme phenylalanine hydroxylase?
(A) Cystic Fibrosis
(B) Sickle Cell Anemia
(C) Phenylketonuria (PKU)
(D) Huntington’s Disease

11. : Which of the following represents a chromosomal abnormality where an individual has three copies of chromosome 18?
(A) Down Syndrome
(B) Edwards Syndrome
(C) Klinefelter Syndrome
(D) Turner Syndrome

12. : In human genetics, what is the term for the observable characteristics of an organism resulting from the interaction of its genotype and environment?
(A) Phenotype
(B) Genotype
(C) Allele
(D) Karyotype

13. : What type of inheritance pattern is demonstrated by the expression of a trait in all generations of a family pedigree, with both males and females affected equally?
(A) Autosomal recessive
(B) Autosomal dominant
(C) X-linked recessive
(D) X-linked dominant

14. : Which genetic term describes the genetic makeup of an organism?
(A) Phenotype
(B) Genotype
(C) Allele
(D) Chromosome

15. : In which phase of meiosis does independent assortment of chromosomes occur?
(A) Prophase I
(B) Metaphase I
(C) Anaphase II
(D) Telophase II