Question

Please answer all five multiple choice questions, i will give a thumbs up!

2014 BIOLOGY

21. What is one advantage of budding as a form of reproduction in animals?

a) It allows the species to survive long periods of unsuitable environmental conditions.

b) It increases genetic variability in the species.

c) It allows rapid colonisation of a favourable environment.

d) It allows the species to get rid of harmful mutations.

22. In animals where females bear the greater burden of parental care,

a) males and females have the same mating strategies.

b) females produce a much greater number of offspring by mating with multiple males.

c) males and females have very similar morphology.

d) males produce a much greater number of offspring by mating with multiple females.

23. From earliest to latest, the overall sequence of early development proceeds as follows:

a) first cell division → synthesis of embryo's DNA begins → acrosomal reaction → cortical reaction

b) cortical reaction → synthesis of embryo's DNA begins → acrosomal reaction → first cell division

c) cortical reaction → acrosomal reaction → first cell division → synthesis of embryo's DNA begins

d) acrosomal reaction → cortical reaction → synthesis of embryo's DNA begins → first cell division

25. In an egg cell treated with EDTA, a chemical that binds calcium and magnesium ions, the

a) acrosomal reaction would be blocked.

b) fusion of sperm and egg nuclei would be blocked.

c) fast block to polyspermy would not occur.

d) fertilization envelope would not be formed

27. Which of the following statements about gene expression is not true?

a) It is the process which ultimately leads to synthesis of a protein as encoded in the DNA.

b) It can be ‘switched on’ or ‘switched off’ by regulatory factors.

c) Gene expression of homeotic genes varies in time (i.e., age of the embryo) and space (i.e., region of the embryo).

d) House keeping genes are expressed intermittently

Answer 1

Answer-

21- C is the answer.It allows rapid colonisation of a favourable environment.

22- D is the answer. Males produce a much greater number of offspring by mating with multiple females.

23- D is the answer. Acrosomal reaction → cortical reaction → synthesis of embryo's DNA begins → first cell division

25- D is the answer. Fertilization envelope would not be formed.

27- D is the answer. Because housekeeping genes are constitutive genes which express themselves in all the cells of the organism all the time at almost constant rate.