Biology Answers

A sample containing mixture of methionine, proline, cysteine, histidine, and glutamic acid was subjected to electrophoresis at pH 4. Show the migration of each amino acid in the electrophoresis matrix by drawing spots corresponding to the location of each amino acid. Label each the spots with the 3-letter abbreviation of the amino acid. Show the calculation of pI of each amino acid below. The ionization of each amino acid is no longer necessary to be illustrated.

Illustrate below the structure of the peptide with the sequence WATERS

a. What is the amino acid residue at the C-terminal of the peptide? __________________

b. What is the amino acid residue at the N-terminal of the peptide? __________________

c. How many peptide bonds are present in the peptide? __________________

Name the following peptides with the following amino acid sequence:

 GSM

 CARE

 DREAMER

 LIPIDS

 VITAMINS

Why are conjugation and sporulation not considered as forms of reproduction in prokaryotic cells? What are the main purposes of these processes?

Are tissues considered as constant features of living things? Explain your answer shortly.

Two sister species of butterflies, Heliconius melpomene and Heliconius cydno, each mimic a different model species. While these species are largely sympatric, there are some areas in which H. melpomene occurs alone (i.e., allopatric to H. cydno). Mating studies show that H. melpomene females from these allopatric populations are more responsive to courtship by H. cydno males than are H. melpomene females from sympatry. What mechanism could explain this stronger behavioural isolation in sympatric compared to allopatric H. melpomene populations?

a) trait-based reproductive barriers

b) reinforcement

c) ecological speciation

d) prezygotic isolation

e) behavioural isolation

Two sister species of insects feed on different parts of the

same plant species, one on the stem and the other on the leaves. Hybrids between the insect species grow more slowly and have reduced survival, indicating some form of postzygotic barrier. Outline conceptually what you would need to show to infer that ecological speciation is the mechanism generating this reproductive barrier, and briefly

describe how you might test this.

Which promoter initiates which life cycle (lysogenic & Lytic)? Mention both types of promoters and their characteristics.

Which consumes energy anabolic or catabolic

Tendency of the solute to spread throughout the solution until the composition is homogeneous