DEPARTMENT OF LIFE AND CONSUMER SCIENCES
BLG1501
SEMESTER 2
TUTORIAL LETTER 201/2012
ASSIGNMENT 02
MEMORANDUM
2
BLG1501/201/S2/2012
Dr Monde Nyila 011 471 2294 e-mail: nyilama@unisa.ac.za
Question 9.1: What is the summarised equation for cellular respiration?
(6)
Answer:
Organic compounds + Oxygen → Carbon dioxide + Water + Energy
OR
C6H12O6 + 6O6 → 6C02+ 6H20 + Energy (ATP + heat)
Question 9.6: Explain why ATP is required for the preparatory steps of glycolysis.(2)
Answer:
ATP is used to phosphorylate the fuel molecules.
Question 9.12: Compare in tabulated form the processes of fermentation and cellular respiration.
(6)
Answer:
Fermentation
The final electron acceptor is an
Cellular respiration
The final electron acceptor is oxygen
organic molecule pyruvate ( lactic acid fermentation) or acetaldehyde (alcohol fermentation) Harvests less energy
Harvests more energy
Yields 2 ATPs
Yields 38 ATPs
Anaerobic conditions
Aerobic conditions
3
BLG1501/201/S2/2012
Question 10.3: Make labelled drawings to illustrate the different phases of mitosis in an animal cell with two chromosomes.
(20)
Answer
Question 11.6: Tabulate the key differences between mitosis and meiosis.
(14)
Answer:
Mitosis
Meiosis
DNA replication occurs during
DNA replication occurs during
interphase before mitosis begins
interphase before meiosis 1 begins
One division
Two divisions
Synapsis does not occur
Synapsis occurs during prophase 1
Two daughter cells, each 2n and
Four haploid cells, each containing half
genetically identical to parent cell
as many chromosomes as the parent cell
Effects growth and repair
Produces gametes
4
BLG1501/201/S2/2012
Question 12.5: A purple flower with an unknown genotype is crossed with a white flower. Determine the genotype of the purple flower if purple (P) is dominant and white (p) is recessive.
(20)
Answer:
P-generation:
The purple flower must have the P-allele because purple is dominant. We do not know