13th International Biology Olympiad Latvia, 2002 Ministry of Education and Science University of Latvia Association of Biology Teachers
4 Kronvalda boulv., Riga LV-1586, LATVIA phone: +371-7034860, +371-7334125, Fax: +371-7223801, email: ulkoro@latnet.lv

Final Report

• 4. Tasks
  • 4.1. Practical tasks
  • 4.2. Theoretical tasks
    • 4.2.1. Theoretical test Part A
    • 4.2.2. Theoretical test Part B

4.2. Theoretical tasks

4.2.1. Theoretical test Part A

Cell Biology

A1. In which processes microtubules could be involved?

	Beating of cilia and flagella	Movements of chromatids	Osmoregulation	Movement of organelles in living cells
A.	+	+	+	-
B.	+	-	-	-
C.	+	+	-	+
D.	-	-	+	-
E.	-	+	+	+

A2. Which of the following is an example of microfilament motion in nonmuscular animal cells?

A. Rigor mortis

B. Flagellar movement

C. Cytokinesis

D. Chromosome movement during meiosis

E. Beating of cilia

A3. When or where it is possible to observe nucleolus?

A. During meiosis

B. In senescent plant cells

C. During apoptosis

D. In senescent animal cells

E. During the elongation of plant cells

A5. Which statement about actin microfilaments is correct?

A. They are found only in animal muscle cells and involved in the contractions of

sacromeres

B. They are involved in the formation of the cell

cleavage furrow in plant and animal cells

C. They are found only in plant cells and involved in the movement of chloroplasts

D. They are found in plant and animal cells and involved in the movement of vesicles

E. They are found in all eukaryotic cells and involved in the movement of pyruvate

from cytosol to mitochondrial matrix

A6 . Which statement about genetic material is incorrect ?

A. There are viruses possessing genomes, built of RNA

B. There are cell organelles possessing their own RNA genomes

C. In the cells of bacteria genetic material may persist in extrachromosomal form

D. Genetic material of eukaryotes is made of DNA

E. Admission of foreign DNA in a cell is not necessarily lethal for the cell, especially in the case of eukaryotic cell

A7. Which of the following is not the metabolic role of tricarboxylic acid (TCA) cycle?

A. Completion of carbohydrates oxidation

B. Supply of metabolic precursors for biosynthesis of some amino acids

C. Supply NADH for the respiratory chain

D. Supply NADPH for biosynthetic reactions

E. Production ATP or GTP

A8. Which statement about the chemiosmotic theory is not correct?

A. While electrons in the electron transport chain are passing through the transporters located on the inner membrane of mitochondria, protons are pumped out of the matrix by the respiratory complexes I, III and IV

B. This theory explains coupling between oxidation and phosphorylation

C. The protons return to the mitochondrial matrix through the proton-dependent ATP synthase

D. This theory is valid for forming of ATP in photosynthetic electron transport chains

E. The respiratory proton transport is driven by conformational oscillations of the

energy-coupling membrane bilayer

A9. Which three amino acids can be formed directly in one step from the following metabolic intermediates: pyruvate, oxaloacetate and -ketoglutarate ?

	Pyruvate	Oxaloacetate	-ketoglutarate
A.	Alanine	Aspartate	Glutamate
B.	Lysine	Asparagine	Glutamine
C.	Serine	Arginine	Tyrosine
D.	Threonine	Glycine	Tryptophan
E.	Histidine	Proline	Leucine

A 10. How many different primary structures approximately may represent a 10 residues long polypeptide, which is a random combination of 20 naturally occurring amino acids?

A. 10

B. 200

C. 40 00

D. 10 000 000 000 000

E. 100 000 000 000 000 000 000

A 11. Apoptotic cell undergoes a series of changes including membrane blebbing, fragmentation of DNA creating a vacuolar nucleus and following fragmentation of nucleus forming micronuclei. Researchers used onion cells to study the cell death. Which picture corresponds to cell with nuclear fragmentation?

A	B
C	D	E

A 12 . What is the correct sequence of events during immunological responses to viral infection?

Code

1. Natural killer cell activation
2. Antibody production
3. Cytotoxic T cell activation
4. Virus invasion

Time
A.	4	2	3	1
B.	1	4	3	2
C.	3	2	1	4
D.	4	1	3	2
E.	4	3	2	1

 

	A 13. The diagram shows a simplified scheme of three stages (P, Q and R) of aerobic respiration. What substances are X, Y, Z?
		X	Y	Z
	A.	Acetyl CoA	NADH2	Lactic acid
	B.	Water	CO2	Dehydrogenase
	C.	NADH2	CO2	Dehydrogenase
	D.	NADH2	Water	Peroxidase
	E.	Pyruvate	CO2	NADH2

A 14. Some genes in the genome of bacteria are organised in operons. Which statement about such operons is correct?

A. Genes of the operon are arranged in mosaic structures of introns and exons

B. Translation of all genes of one operon starts at the same initiation codon

C. All genes of the same operon are not expressed simultaneously

D. Proteins encoded in the genes of the same operon are translated from one common mRNA molecule

E. Translation of all genes from the same operon is terminated at the same common STOP codon

A 15. Which of the given components is not needed for DNA replicationin vivo?

A. Single stranded DNA template

B. Deoxy-nucleoside monophosphates (dAMP, dCMP, dGMP, dTMP)

C. RNA polymerase – primase

D. Single-strand DNA binding proteins

E. DNA polymerase

A 16. For numerous groups of organisms genes are split in exons and introns. Which statement about gene expression is correct?

A. The genetic information of only some introns is used for synthesis of proteins

B. A separate promoter induces the transcription of each exon

C. During RNA processing the sequences of introns are removed as a result of splicing of the pre-mRNA

D. Translation of each exon starts with its own initiation codon (AUG)

E. During the translation ribosomes are jumping over the intronic part of mRNA

A 17. Human hormone insulin is synthesised as pre-protein and modified before secretion in extracellular space. It contains two polypeptide chains. Which statement about these chains is correct?

A. They are synthesised on cytosolic ribosomes and modified in Golgi apparatus

B. They are synthesised on ER ribosomes and modified in Golgi apparatus

C. One chain is synthesised on cytosolic ribosomes, another on ER ribosomes and

modified in cytosol and Golgi apparatus

D. They are synthesised on cytosolic ribosomes and modified in the lumen of lysosomes

E. They are synthesised on cytosolic ribosomes and modified in cytosol

A 18. Which statement regarding the amount of genomic DNA per cell (M) during the cell cycle is correct?

A. M_DNA[G₁] = M_DNA[_{meiosis prophase II}]

B. M_DNA[_{meiosis prophase II}] = 2 x M_{DNA[meiosis prophase I}]

C. M_DNA[G₁] = M_DNA[G₂]

D. M_DNA[G_{2 after mitosis}] < M_DNA[G_{2 after meiosis}]

E. M_DNA[_{telophase of mitosis}] > M_{DNA[telophase I of meiosis}]