BBS1005 - Human Genetics - Cases + lectures & practicals (part 2)

For which DNA repair mechanism is the sister chromatid used as a template? A. Non-homologous end-joining  G1 to S B. Homologous end-joining  S to G2 C. Mismatch repair D. Direct reversal

Antwort: B. Homologous end joining  S to G2

2. Correct sequence of cell stages in spermatogenesis A. Spermatocytes- spermatids- spermatognia- spermatozoa B. Spermatogonia- spermatids- sprmatocytes- spermatozoa C. Spermatogonia - spermatocytes- spermatids- spermatozoa D. Spermatocytes- spermatogona- spermatids- spermatozoa

Antwort: C. Spermatogonia - spermatocytes- spermatids- spermatozoa

3. A mutational event, in which adenine is replaced by guanine, is called A. Transition B. Transcription C. Transversion D. Frame shift mutation

Antwort: A. Transition

4. Where does meiosis halt in oogenesis? A. Metaphase 1 B. Prophase 2 C. Metaphase 2 D. Anaphase 1

Antwort: C. Metaphase 2

5. Choose three processes that occur in meiosis that do not occur in mitosis. - haploid cells produced - chiasmata formation - crossing over - homologous pairs associate and line up - two phases/divisions

Antwort: - haploid cells produced - crossing over - two phases/divisions

Which of the embryonal stages below is the last stage where all cells are totipotent? A. Zygote B. Blastocyst C. 8-cell D. 16-cell

Antwort: D. 16-cell (-> morula) The blastocyst is already totipotent

2. What is the name of the glycoprotein receptor that the sperm binds to on the zona pellucida? A. ZP1 B. ZP2 C. ZP3

Antwort: C. ZP3

3. What step comes first in IVF? A. Egg and sperm combine. B. Stimulate ovulatory process. C. Place in culture for 2 - 6 days. D. Remove ovum.

Antwort: B. Stimulate ovulatory process.

4. A wave of which molecule causes the release of the content of the cortical granules? A. Na+ B. Ca2+ C. K+ D. Cl-

Antwort: B. Ca2+

5. Which protein aids in the accumulation of blastocoelic fluid?

Antwort: Na+/K+ ATPase