Biology Questions

Using the quick and dirty formula given in class what is the approximate melting temperature of the following dsDNA fragment 5 ATG GTG AAT CTG ACT GCT GCT GAG 3 Tm C

Formation of a phosphodiester bond between two nucleotides is energetically unfavorable reaction How is then DNA synthesis driven forward O The phosphodiester bond forms between the 3 hydroxyl of the ribose at the end of the growing chain and the alpha phosphate of the incoming nucleotide A molecule of pyrophosphate PPI is released in the process and is further hydrolyzed into inorganic phosphate P Thus a net of one high energy bond is consumed in the process which drives the process forward PPP 5 DNA 3 OH dNTP PPP 5 DNAn 1 3 OH PPI 2Pi The polymerase is hydrolyzing an ATP molecule the general currency molecule of the cell for every new nucleotide that is added to the growing chain Thus a net of two high energy bonds are consumed in the process which drives the process forward PPP 5 DNA 3 OH dNTP ATP PPP 5 DNAn 1 3 OH PPI 2Pi The phosphodiester bond forms between the 3 hydroxyl of the ribose of the incoming nucleotide and the alpha phosphate at the 5 end of the the growing chain A molecule of pyrophosphate PPI is released in the process and is further hydrolyzed into inorganic phosphate Pi Thus a net of one high energy bond is consumed in the process which drives the process forward dNTP OH PPP 5 DNA 3 OH PPP 5 DNAn 1 3 OH PPI 2Pi

Listen to this 60 seconds podcast and then answer the following question http www scientificamerican com podcast episode cfm id mammoth hemoglobin could provide co 11 09 19 ref worth What were the methods likely used for the analysis of the mammoth hemoglobin Mammoth DNA fragments encoding for the two globin subunits of hemoglobin were amplified using PCR X ray crystallography was used to determine the structure of the DNA encoding for the hemoglobin protein Hemoglobin protein in sufficient quantities was purified from the mammoth remains and the amino acid sequence was determined directly from the protein Sanger s chain termination sequencing was used to determine the sequence of the genes encoding the two globin subunits

Imagine DNA like molecules were recovered from several single celled organisms found in the liquid water ocean on the Jupiter Moon Europa The molecules consist of a double stranded polymers whose monomeric subunits are composed of glycerol phosphate and nitrogenous bases of which four kinds were found The bases in this glyceronucleic acid GNA are symbolized as a y and 5 Alpha Beta Gamma and Delta The monomers are linked through phospodiester bonds and the bases form hydrogen bonds between the strands according to the following rules For every a there are twice as many s for every y there are twice as many 6s GNA molecules from one such organism contain 20 Bs what do you expect is the percentage of ys 30 0 35 0 46 7 23 3 13 3 26 7

The following is the DNA sequence coding for the hemoglobin beta subunit mentioned in the podcast What is the complementary strand s sequence Note that by convention and unless stated otherwise single stranded nucleic acids are always written with their 5 ends on the left 5 ATG GTG AAT CTG ACT GCT GCT GAG 3 Enter the nucleotides of the complementary strand in groups of three below pay attention to the orientation 5 3

You identify an E coli mutant which has a defect in its DNA replication A closer examination reveals that DNA Pol III is functional but seems to exhibit extremely low processivity A mutation in which of the following structures is the most likely hypothesis to explain the defect the clamp loader the topoisomerase enzyme the sliding clamp the pol III holoenzyme the t proteins

Question 9 When a cell secretes a growth factor that binds to receptors onits own membrane preventing it fromproliferating this is an example of endocrine signaling autocrine signaling O paracrine signaling 0 5 pts contact dependent signaling direct intercellular signaling

Which of the following statements referring to the schema of a replication bubble is true 5 3 A C E H B D O A and D are leading strands C and B are lagging strands A and B are lagging strands C and D are leading strands A and C are lagging strands B and D are leading strands OA and D are lagging strands B and C are leading strands O A and B are leading strands C and D are lagging strands O A and C are leading strands B and D are lagging strands F 3 5

Which of the following statements referring to the schema of a replication bubble is true more than one true answer is possible 5 3 A C E H B O The 5 end of DNA strand C is close to H The 5 end of DNA strand B is close to E The 5 end of DNA strand D is close to H The 5 end of DNA strand A is close to E F3 G 3in 5

Which of the following statements referring to the schema of a replication bubble is true E 5 3 A C H B D F3 5 The replication bubble spreads bidirectionally from E and H toward the right F and G and the left I and J The replication bubble spreads bidirectionally from 5 to 3 J to F upper strand and G to I lower strand O The replication bubble spreads from I and J toward the right F and G The replication bubble spreads from F and G toward the left I and J

What is difference between ddNTPs and dNTPs The ddNTPs have a 2 H and a 3 H while dNTPs have a 2 H and a 3 OH The ddNTPs have a 2 H and a 3 OH while dNTPs have a 2 H and a 3 H The ddNTPs have a 2 H and a 3 H while dNTPs have a 2 OH and a 3 OH The ddNTPs have a 2 OH and a 3 H while dNTPs have a 2 H and a 3 OH The ddNTPs have a 2 OH and a 3 OH while dNTPs have a 2 H and a 3 H

gene consists of the entire molecule sequence required for synthesis of a n or a n

In their famous experiment which of the following would Meselson and Stahl have observed after one cycle of replication in 14N medium if DNA replication were dispersive DNA molecules containing one strand of 15N DNA and one strand of 14N DNA ODNA molecules containing two 15N DNA strands only DNA molecules containing two 14N DNA strands only A mix of DNA molecules composed of a random mixture of 15N DNA segments and 14N DNA segements An equal number of DNA molecules containing two 15N DNA strands and DNA molecules containing two 14N DNA strands

In the reaction pyruvate CoA NAD acetyl CoA CO 2 NADH O Pyruvate is oxidized and NAD is reduced O Pyruvate is oxidized and CoA is reduced O Pyruvate is reduced and CoA is oxidized O Pyruvate is reduced and NAD is oxidized

A difference between a chicken s foot and a duck s foot is the presence or absence of webbing a duck s foot has webbing between the digits while a chicken s foot lacks the webbing Which of the cell processes that play a role in producing tissues organs is NOT happening to a great extent during development of a duck s foot differentiation O cell connections cell growth O apoptosis 0 5 P Ocell division

The heart is a n O tissue epithelial O tissue connective O organ connective organ muscle organ epithelial Previous composed mainly of tissue

The process through which cells can detect and respond to signals in their extracellular environment is O sensory response O cell sensation O reception cell communication O transduction

If you tear your Achilles tendon you are damaging ECM rich tissue O connective O epithelial O nervous O muscle

Gap junctions in animal cells are most similar to inplant cells O hemidesmosomes O plasmodesmata O primary cell walls O tight junctions middle lamella

0 5 p In the citric acid cycle some intermediates are used in other metabolic reactions Which of the following adaptations would need to be made by a cell in response to this O Cells would have to use energy sources other than glucose for metabolism O Some oxaloacetate would need to be produced through an alternative pathway to combine with acetyl CoA O Some citrate would need to be produced through an alternative pathway to combine with acetyl CoA O The citric acid cycle would eventually shut down when it ran out of int

Question 16 When a neurotransmitter released from one neuron binds to a O enzyme linked receptor O G protein coupled receptor nuclear receptor O ligand gated ion channel O voltage gated ion channel on a secondneuron that neuron depolarizes and fires

Proteins Amino acids Carbohydrates Sugars Glycolysis Glucose Glyceraldehyde 3 phosphate Pyruvate Acetyl CoA Citric acid cycle Oxidative phosphorylation Fats Glycerol Fatty acids The conversion of pyruvate to acetyl CoA is irreversible Predict what would happen to fatty acidsas a result of thi Fatty acidscannot be metabolized in the citric acid cycle Fatty acidscannot be converted into carbohydrates O Fatty acids can be converted into carbohydrates O Fatty acidscan

The production of second messengers in signal transduction offers at least two advantages speed and O reversibility O specificity O affinity O amplification one to one stoichiometry

Question 10 When epidermal growth factor binds to its O enzyme linked receptor O mechanoreceptor O G protein coupled receptor O ligand gated ion channel receptor Othermoreceptor 0 5 pts the receptor phosphorylates itself triggering a signal transduction pathway

Following its initial activation how does a G protein become inactivated O The G protein a subunit GTP is hydrolyzed to GDP allowing reassociation of the G protein a subunit and By dimer The receptor becomes internalized O The G protein a subunit is digested and recycled O The G protein a subunit containing a GTP eventually reassociates with the G protein bg dimer O It spontaneously loses activity within a few seconds

Mutations that inhibit the function of photosystem I but not photosystem II would result in a plant cell that could still generate O produce O 2 ATP and NADPH O produce CO 2 and ATP O produce O 2 ATP and NADP O produce ATP and NADP O produce ATP andNADPH

Question 7 Where does the Calvin cycle occur O chloroplast stroma Othylakoid lumen O chloroplast outer membrane thylakoid membrane O chloroplast inner membrane

Blue light has energy than red light and is by a green leaf more absorbed O less reflected more reflected O less absorbed

If you wanted to install lights to grow plants indoors the type of light would you want to use is microwaves because it has low energy wavelengths O ultraviolet because it has high energy wavelengths O visible light because it has low energy wavelengths O gamma rays because it has high energy wavelengths O infrared because it has high energy wavelengths

IDENTIFY Pause at line 188 How would you describe the land lady s personality Explain Garm and but ultimateN Secretive unsettling inpiting nat herself 190 Circle the words in lines 189 194 that show what Billy thinks of the landlady presents A charming gost but her behavior and Responses become areasing IDENTIFY INTERPRET Pause at line 201 Do you agree that Billy is lucky Explain Now the fact that his landlady appeared to be slightly off her rocker didn t worry Billy in the least After all she not only was harmless there was no question about that but she was also quite obviously a kind and generous soul He guessed that she had probably lost a son in the war or something like that and had never gotten over it So a few minutes later after unpacking his suitcase and washing his hands he trotted downstairs to the ground floor and entered the living room His landlady wasn t there but the fire was glowing in the hearth and the little dachshund was still sleeping soundly in front of it The room was wonderfully warm and cozy I m a lucky fellow he thought rubbing his hands This is a bit of all right He found the guest book lying open on the piano so he took out his pen and wrote down his name and address There were only two other entries above his on the page and as one always does with guest books he started to read them One was a Christopher Mulholland from Cardiff The other was Gregory W Temple from Bristol That s funny he thought suddenly Christopher Mulholland It rings a bell Now where on earth had he heard that rather unusual name before Was it a boy at school No Was it one of his sister s numerous young men perhaps or a friend of his father s No no it wasn t any of those He glanced down again at the book 200 wave of the hand and went quickly out of the room and closed the door 210 Christopher Mulholland 231 Cathedral Road Cardiff Gregory W Temple

crophoblast stem TS cells using embryonic stem ES cells as a control A Nanog Oct 4 B actin ES 0 M TS Question 0 1 5 200 TSA M 5 5 aza dC UM RT Figure A RT PCR data for Oct 4 Nanog and actin in TS cells exposed to 5 aza dC 1 or 5 m a DNA methylase inhibitor and or TSA 200 nm a histone deacetylase inhibitor

3 Explain how the random alignment of homologous chromosomes during metaphase I contributes to variation in gametes produced by meiosis 20 pts

1 Complete the nucleotide sequence of DNA replication for the daughter strand 1 12 12 pts A G T C GA T C A G T C

7 In guinea pigs black coat color is dominant over white coat color Show the genotypic and phenot ratios of the offspring of a mating between two heterozygous black guinea pigs 30 points SHOW YOUR WORK 1 What is the phenotypic ration of the offspring 3 1 2 What is the genotype ratios of the offspring 1 2 1

2 Identify the Phases of Meiosis A B and C 15 pts A B 65 C

4 Transcribe the DNA nucleotides from the parent strand onto the mRNA strand 1 12 12 pts G A T A C DNA G A G A T T N A

5 Identify the Phases of Meiosis A B and C 15 pts A B C

6 Translate the mRNA strand into the corresponding amino acids using the chart provided 20 pts U C G G C A C C CG A

6 Translate the mRNA strand into the corresponding amino acids using the chart provided 20 pts U C G G CA C C C G A

Drag the appropriate labels to their respective targets Rectus abdominis Transversus abdominis Linea alba External oblique Aponeurosis of external oblique Internal oblique Inguinal ligament Rectus sheath Rese

Drag the appropriate labels to their respective targets Calcaneal Achilles Semimembranosus tendon Gastrocnemius Adductor magnus LALO Biceps femoris Gluteus medius Soleus Semitendinosus Reset Help Gluteus maximus Fibularis longus

the appropriate Soleus Calcaneal Achilles tendon bels to their respective targets Fibularis longus Gluteus medius MO Semimembranosus Gastrocnemius Semitendinosus Gluteus maximus Reset Biceps femoris Adductor magnus nu He

Vastus lateralis Soleus Tibialis anterior Gracilis Sartorius Vastus medialis Pectineus Adductor longus Fibularis longus Gastrocnemius Extensor digitorum longus Iliopsoas Rectus femoris

Drag the appropriate labels to their respective targets Brachialis Pectoralis minor Triceps brachii Pectoralis major Rectus abdominis O Sternocleidomastoid Biceps brachii Transversus abdominis Brachioradialis External oblique Platysma Deltoid Internal oblique Re

pons midbrain brain stem cerebrum hypothalamus thalamus medulla oblongata cerebellum

Question 2 The nucleotides within DNA are composed of a sulfur group ribose sugar and nitrogenous base O sulfur group deoxyribose sugar and nitrogenous base O phosphate group deoxyribose sugar and nitrogenous base O phosphate group ribose sugar and nitrogenous base O phosphate group hexose sugar and nitrogenous base

Question 1 Which of the following is NOT a criterion for an organism s genetic material To transmit information the genetic material must be replicated O The genetic material must be dynamic changing rapidly in response to changes in the environment O The genetic material must contain information necessary to construct a whole organism Genetic material must account for the known variation within each species and among different species The genetic material must be transmitted from parent to offspring

Question 2 In the small intestine food molecules pass from the lumen of the intestine into the individual cells lining the intestine and then into the circulatory or lymph system of the body If the digested molecules can leak into the abdominal cavity then must have been damaged Odesmosomes O gap junctions O focal adhesions Ohemidesmosomes 0 5 pts O tight junctions

Question 1 These act as rivets anchoring adjacent cells together at spots throughout the cell O desmosomes O adherens junctions focal adhesions hemidesmosomes fibronectin

Males are more often affected by sex linked traits than females because males are hemizygous for the X chromosome male hormones such as testosterone often alter the effects of mutations on the X chromosome X chromosomes in males generally have more mutations than X chromosomes in females