| Question | Answer |
| Plants develop brightly coloured flowers to attract animals. Which process is directly assisted by this adaptation? | fertilization
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What controls the flowering process in long-day plants? | Pr is converted by red light to Pfr which acts as an inhibitor of flowering
| How do mineral ions in the soil move to the root through the soil? | Mass flow of water
| What is a difference between the features of monocotyledons and dicotyledons? | Parallel-veined leaves v Net-veined leaves
| What causes stomata to close? | The presence of abscisic acid
| The lengths of a sample of tiger canines were measured. 68% of the lengths fell within a range between 15 mm and 45 mm. The mean was 30 mm. What is the standard deviation of this sample? | 15
| What does a small standard deviation signify? | The data is clustered closely to the mean value.
| The t-test is used to test the statistical significance of a difference. What is that difference? | Between the means of two samples
| What do error bars on graphs show? | how variable the data is
| What happens in crossing over? | Exchange of genetic material between homologous chromosomes
| What are homologous chromosomes? | Each gene is at the same locus on both chromosomes.
| What is the probability that the child will have hemophilia? | 0%girl 50%boy
| Which enzymes are needed to produce recombinant plasmids to be used in gene transfer? | Restriction enzyme (endonuclease) and DNA ligase
| A parent organism of unknown genotype is mated in a test cross. Half of the offspring have the same phenotype as the parent. What can be concluded from this result? | The parent of unknown genotype is heterozygous.
| What is the difference between the alleles of a gene? | their base sequence
| Which of the following is the cause of sickle-cell anemia? | Glutamic acid is replaced by valine.
| A man of blood group A and a woman of blood group B have a child. If both are heterozygous for the gene, what are the chances of them having a child with blood group B? | 25%
| How is hemophilia inherited? | sex linked
| What kind of inheritance does skin colour represent? | polygenic
| A cell in the testis of a male chimpanzee (Pan troglodytes) contains 48 chromosomes. It is about to undergo meiosis. How many molecules of DNA will be present in the nucleus of the sperm cells just after meiosis? | 24
| What process Samples cells from the placenta? | Chronic villi sampling
| How can fragments of DNA be separated? | gel electrophoresis
| Why can DNA profiling be used to determine paternity? | Half the genes of children are the same as their father’s.
| Which 2 processes promote variation in a species? | meiosis and fertilization
| What is the set of alleles that an individual possesses? | genotype
| Which phase of cell division is photographed in order to make a karyotype? | metaphase
| Which process is used in polymerase chain reaction (PCR)? | DNA replication
| If the haploid number of a species is 14, how many chromatids will there be in metaphase I in a dividing diploid cell? | 56
| If an organism that is homozygous recessive for a trait is crossed with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the first generation? | 50%
| What is placed into the uterus after the process of in vitro fertilization (IVF)? | embryos
| What are the fundamental structural units of eukaryotic chromosomes? | nucleosome
| When do chiasmata form in meiosis? | prophase I
| What conclusions did Mendel make from his experiments? | Genes for two different characteristics are inherited separately.
| In fruit flies (Drosophila melanogaster) grey body is dominant to black body and normal wings are dominant to vestigial wings. If a heterozygous grey fruit fly is mated with a black-bodied fruit fly, what proportion of the offspring would be black? | 50%
| What chemicals are a component of eukaryotic chromosomes? | DNA and proteins
| A small amount of a suspect’s DNA is obtained from a crime scene. What techniques would be used to carry out DNA profiling? | PCR and gel electrophoresis
| The Human Genome Project allowed the first accurate estimates of the number of different genes in the human genome. What was a typical estimate, based on the results of the Human Genome Project? | 25,000
| How many autosomes are there in a human sperm? | 22
| What type of inheritance pattern determines a character that is controlled by two or more genes? | polygenic
| How are plasmids used in biotechnology? | gene transfer
| What is the cell theory? | I Living organisms are composed of cells. II. All cells come from pre-existing cells by mitosis. III. Cells are the smallest units of life.
| What type of bond exists between water molecules? | hydrogen
| The percentage of thymine in the DNA of an organism is approximately 30%. What is the percentage of guanine? | 20%
| What is a structural change of a protein that results in the loss of its biological properties? | denaturation
| How do cells capture the energy released by cell respiration? | produce ATP
| What is the source of the oxygen released into the air as a product of photosynthesis? | water in photosystem 2
| What property of water makes it a good evaporative coolant? | High latent heat of evaporation
| What is the difference between galactose and lactose? | Lactose is a disaccharide and galactose is a monosaccharide.
| Which process produces the most ATP per molecule of glucose? | Aerobic respiration
| | green
| How many molecules of water are required to completely hydrolyse a polypeptide made up of 23 amino acids? | 22
| What does a nucleosome consist of ? | DNA + histones
| What are Okazaki fragments? | Short sections of DNA formed during DNA replication
| The sequence of nucleotides in a section of RNA is: GCCAUACGAUCG What is the base sequence of the DNA sense strand? | GCCATACGATCG
| Where is chlorophyll found in a plant cell? | thylakoid membrane
| What is produced by the light-dependent reactions of photosynthesis and used in the Calvin cycle? | ATP and NADPH
| Which base pair is connected by three hydrogen bonds? | Cytosine and Guanine
| Which molecules are found in both DNA and RNA? | phosphate, adenine, cytosine, guanine
| The photosynthetic activity of desert plants is often reduced in the middle of the day. What is the most reasonable explanation for this fact? | the stomata close to preserve water and gas exchange decreases
| The decarboxylation of pyruvate occurs during what stage of Cellular Respiration? | link reaction
| Where does the RNA polymerase bind during the process of transcription? | promoter
| A plant is exposed to increasing light intensity from very dim to bright light, while the carbon dioxide concentration and temperature are kept at an optimum level. What will happen to the rate of oxygen production? | it will increase to a max level then level off
| In some people, hemoglobin always contains the amino acid valine in place of a glutamic acid at one position in the protein. What is the cause of this? | A base substitution in the hemoglobin gene
| What is a function of cellulose in plants? | make up cell walls
| A controlled release of energy, in the form of ATP, from organic compounds in cells is known as | cellular respiration
| What is the reason for Okazaki fragments being formed during DNA replication? | To enable replication of the 3′ → 5′ (lagging) strand
| What is removed during the formation of mature RNA in eukaryotes? | introns
| During glycolysis a hexose sugar is broken down to two pyruvate molecules. What is the correct sequence of stages? (use the words: lysis,oxidation and phosphorylation) | Phosphorylation → lysis → oxidation
| What does the universal nature of the genetic code allow? | transfer of genes among species
| What happens during the formation of Okazaki fragments? | DNA polymerase III adds nucleotides in the 5´ → 3´ direction.
| What is chemiosmosis? | Coupling of ATP synthesis to the electron transport and proton movement
| What chemical reaction is taking place when a dipeptide becomes two amino acids? | Hydrolysis
| What is a polysome? | Several ribosomes using a mRNA molecule to synthesize protein at the same time
| What does oxidation involve? | Loss of electrons, loss of hydrogen, or gain of oxygen
| What happens in the light-independent reactions of photosynthesis? | reduction of carbon dioxide (to form glucose)
| Which two tissues of a leaf are photosynthetic? | Palisade mesophyll and spongy mesophyll
| What is a codon? | A sequence of nucleotides on mRNA that corresponds to an amino acid
| What happens as an enzyme becomes denatured? | enzyme works slower or not at all
| What happens during the pathway of glycolysis? | glucose is broken down into 2 pytruvates, 2 ATP and 2 NADH
| What is light energy used for during photosynthesis? | to make ATP and NADPH
| Blood is a water-based transport medium. Which property of water makes it a good transport medium? | versatility as a solvent
| What is replicated by a semi-conservative process? | DNA
| TATCGCACG What are the anticodons of the three tRNA molecules that correspond to this sequence? | UAU, CGC and ACG
| What is the function of the tRNA activating enzyme? | It links tRNA to a specific amino acid.
| What level of protein structure is formed from interactions between the amino acid side groups? | tertiary
| In the mitochondrial electron transport chain, what is the last electron acceptor? | Oxygen
| Where are complex carbohydrates made in the chloroplast? | stroma
| Where in the cell does the Calvin cycle take place? | in the stroma of the chloroplast
| What is the distinction between highly repetitive DNA sequences and single-copy genes? | The highly repetitive sequences are not transcribed.
| What principle is necessary to preserve the sequence of DNA during replication? | Base pairing is complementary.
| What happens during translation? | Polypeptide synthesis
| What is the role of NADH + H+ in aerobic cell respiration? | To transfer hydrogen to the electron transport chain
| What happens to glycerate 3-phosphate during the light-independent reactions of photosynthesis? | Glycerate 3-phosphate is reduced to triose phosphate.
| What is the advantage of having a small volume inside the thylakoids of the chloroplast? | High proton concentrations are rapidly developed.
| Carbon, hydrogen, nitrogen and sulphur are elements found in living cells. Which is the least common? | Sulphur
| A certain gene in a bacterium codes for a polypeptide that is 120 amino acids long. How many nucleotides are needed in the mRNA to code for this polypeptide? | 360
| What enzyme is used in transcription but not in translation? | RNA polymerase
| If mRNA has a codon CAU, what is the corresponding anticodon on the tRNA molecule? | GUA
| What are pyrimidines in DNA? | Thymine and Cytosine
| Which enzyme removes the RNA primer during replication? | DNA polymerase I
| What is the net production of ATP, per molecule of glucose during the fermentation of glucose to lactate? | 2
| A red blood cell is 8 μm in diameter. If drawn 100 times larger than its actual size, what diameter will the drawing be in mm? | .8mm
| A cell has cytoplasm, a cell wall, naked DNA and ribosomes. Based on this information, what type of cell could this be? | prokaryote(bacteria)
| What do diffusion and osmosis have in common? | they are passive transport
| If a mitochondrion has a length of 5 µm and a student’s drawing of the mitochondrion is 10 mm, what is the magnification of the drawing? | x2000
| What route is used to export proteins from the cell? | Rough endoplasmic reticulum → Golgi apparatus → plasma membrane
| How can cells in a multicellular organism differentiate? | They express some of their genes but not others.
| What happens during the G2 stage of interphase? | Synthesis of proteins
| What is the sequence of stages during the cell cycle? | G1 → S → G2 → mitosis → cytokinesis
| What does facilitated diffusion across a cell membrane require? | pore protein and concentration gradient
| How do prokaryotic cells divide? | binary fission
| During which phase of the cell cycle do chromosomes duplicate? | S
| What feature do plant cells have but not animal cells? | large central vacuole, cell wall
| Cells in the adrenal gland produce the hormone epinephrine and store it in vesicles. To release epinephrine these vesicles are carried to the plasma membrane and fuse with it. What process is occurring? | exocytosis
| During reproduction in flowering plants an embryo sac is produced, containing one haploid nucleus.This haploid nucleus divides by mitosis three times. What is produced? | 8 haploid nuclei
| What does therapeutic cloning involve? | Producing embryonic stem cells for medical use
| In viewing an electron micrograph of a cell, ribosomes, pili and a single circular chromosome are observed. What other structure is likely to be present? | plasmid
| The DNA of a particular cell is damaged, so that the cell continues to divide uncontrollably. What is the possible result? | tumour formation
| What is produced as a result of mitosis? | Two cells, each containing the same number of chromosomes as the original cell |
