Biolody_2015_STPM term U3_Objectives

The characteristics of an unknown marine organism are given below.

⋆ Radial symmetry

⋆ Diploblastic

⋆ Outer layer has stinging cells

What is the most probably phylum for the organism?

• Porifera

• Cnidaria

• Mollusca

• Platyhelminthes

Which level of biological diversity correspond to their explanation?

• Genetic diversity :

  I

  Species diversity :

  II

  Ecosystem diversity :

  III

• Genetic diversity :

  II

  Species diversity :

  III

  Ecosystem diversity :

  I

• Genetic diversity :

  II

  Species diversity :

  I

  Ecosystem diversity :

  III

• Genetic diversity :

  III

  Species diversity :

  I

  Ecosystem diversity :

  II

Which level of ecological organisation are shown above?

I. Habitat

II. Ecosystem

III. Population

IV. Community

• I and III

• I and IV

• II and III

• II and IV

The gross primary productivity of producers in a terrestrial ecosystem is 4000 kJ m^-2 y^-1. The net primary productivity of producers is 1800 kJ m^-2y^-1. If the efficiency of energy transfer from producers to herbivores is 10% and to the next level is 20%, what is the amount of energy obtained by secondary consumers?

• 36 kJ m^-2y^-1

• 80 kJ m^-2y^-1

• 110 kJ m^-2y^-1

• 360 kJ m^-2y^-1

X is a species of fish in a river. After a dam is constructed, individuals of species X upstream are separated from the individuals downstream. Gradually, the individuals in the upstream become a new species. This type of speciation is known as

• intraspecific and allopatric

• intraspecific and sympatric

• interspecific and allopatric

• interspecific and sympatric

Which characteristics correspond to their species?

• I and II

• I and IV

• II and III

• III and IV

Two species of Drosophila live in the same geographical area. One of the species is sexually active in the morning, while the other in the afternoon. Which reproductive isolation mechanism is involved?

• Behavioral

• Gametic

• Mechanical

• Temporal

In a monohybrid cross, the genotypic and phenotypic ratios for the F₂ generation are both 1 : 2 : 1. What do the ratios-indicate?

• Incomplete dominance

• Dominant and recessive interactions

• The presence of lethal gene

• The presence of linked genes

Which statement is not true about genetic code?

• It is a triplet codon.

• It is non-overlapping.

• One amino acid is coded by one genetic code only.

• Most organisms share the same genetic code.

The formation of peptide bonds occurs at

• P

• Q

• R

• S