Test 2 Flashcards

Question

The cell inside water with sucrose glucose and fructose An artificial ‘cell’ is immersed in an aqueous solution with the solute concentrations shown in the diagram. The membrane is permeable to water and monosaccharides (glucose and fructose) and impermeable to disaccharides (sucrose). Which direction will water move?

Answer 1

Solute conc inside cell = .05 (0.03+.02) solute conc outside cell, in solution = 0.03 M (.01 +.01+.01) water flows from low solute to high solute, so itll flow into the cell. Hypotonic. Cell will swell.

Answer 2

A substance that elicits an immune response by binding to receptors of B cells, antibodies, or T cells.

Answer 3

An antigen receptor is a general term for a surface protein, located on B cells that binds to antigens, initiating adaptive immune responses. An antibody is a protein secreted by plasms cells (differentiated B cells) that binds to a particular antigen. they have antigen receptors on the variable region.

Answer 4

due to hypermutations in lymph nodes, biding sites for secondary antibodies are genetically different. thye also have different affinity for some of the antigen. secondarfy response is the second response to same antigen. It is faster and stronger due to memory B cells and mutations. This B-cell mutation and cellular evolution highlights why allergies get worse as you age.

Answer 5

first is a chormosomal inversion, where part of the genome flips 180 degrees in chromosome. second is an insertion or deletion of genetic sequence. gap and shift show an insertion or deletion where vertical genome contains more DNA than horizontal genome. Not possible to know wheter difs in size was due to insertion or deletion because the pattern is the same. not possible to determine if same speices or dif species based on dot plot or full genomnen sequence. def of species is vague.

Answer 6

More primers, the more DNA polymerized even with fixed amounts of dNTPs and DNA polymerase. Amount of primer determines how many new DNA strands can be formed. For E coli, best primers are DNA based primers. they must 3' OH group present becauswe that is where the next base will be added. E coli uses RNA primers.

Answer 7

Older DNA polymerase made fewer nucleotide bases and made more errors. Cofactor ion also impacgts DNA polymerase activity and accuracy, but less than age.

Answer 8

Cd2+ has the strongest error rate of DNA polymerase. similar error rates with a tenth of the conc of nickel.

Answer 9

AB98 cells are between diploid and tetraploid compared to wildtype. AV152 are tetraploid or higher. AB152 has more DNA as indicated by the shift to the right of its nuclear content. Cancer cells escape cell cylfe. They ignore the checkpoints because of incorrect DNA replication or connection of spindle fibers to each chromatid. They get the wrong number of chromosomes (aneuploidy)

Answer 10

Paralogs are duplicate genes within a single species. every chromosome contains manyh paralogs, the data supports that entire genome was duplicated rather than just bits and pieces the origin of vertebrates was a result of duplicated genome inb an invertebrate followed by additional mutations of redundant genes

Answer 11

Primary response peaks 10-17 days after initial exposure, selected B and T cells give rise to effector forms. Secondary response occurs after subsequent exposure to same antigen. Secondary response is fater, of greater magnitune and more prolonged. It relies on memory B cells from first exposure.

Answer 12

Each response for one antigen is unrelated to initial response for a dif antigen. primary response to new antigen is same as any other primary response.

Answer 13

Specific antigens bind to antigen receptors of B cells. B cells msut have irght antigen receptor. Selected B cell divides, forming a clone of identical cells bearing receptors for antigen. some cells developed into short-lived plasma cells that secrete anibodies specific for antigen. other cells develop into long-lived memory B cells that help with next exposure.

Answer 14

Somatic hypermutation: secondary respose B cells mutate rapidly but only in a small segment of their heavy and light chain alleles. coding portions change, and so do B cell's capacity to bind the antigen and receive survival signal. Some mutations increase affinity, and some decrease. It takes place in lymph nodes. Overproduction of B cells, varation in population due to mutations, so B cells with higher affinity survive and reproduce.

Answer 15

An anitbody is shown.l Heave chain B and D. Light chain A and C. Variable region A and B. Antigen binding site A and B. Two compies of same antigen can bind to one antibody. no, antibodies help other cells in immune system identify and kill pathogen. They can also neutralize viruses, making it harder for viruses to infect cells.

Answer 16

immunity can develop thru intro of antigens into body by immunizaiton. immunizations induces primary response and immunological memory, an encounter with the pathogen from which the vaccine was derived trtiggers a rapid and strong secondary immune response

Answer 17

exaggerated responses to certain antigens called allergens

Answer 18

Adaptive immune system relies on pathogen specific recognition. Each B and T lymphocyte is specific for a particular antigen. Your adaptive immune response is also respionsible for immunilogical memory so you can;t get sick from the same pathogen more than once. Vaccines are the inactive form of a pathogen and once injected they start an adaptive immune respionse to the weakened form of the pathogen which results in antibodies and memory cells for future infections.

Answer 19

A genetic mutation is a change in the DNA sequence. Sometimes it can change one nucleotide to another, sometimes mutations can be insertions or deletions of nucleotides. by changing DNA sequence, you can change the mRNA and therfore the codons for the protein that is being made. changing amino acide order changeds shape of the protein which is critical for functionality.

Answer 20

It is synthesized starting on an RNA primer from 5'=3'. DNA polymerase needs a primer with nucleotides with a 3'OH available. DNA polymerase can only add 5'-3' direction. We use an RNA primer.

Answer 21

The top only includes the average, not the variation included. The Y axis also range also amplifies any differences.

Answer 22

On average, two unrelated chimpanzee juveniles differ by about 1.2% On average, two unrelated humans in the world differ by only 0.1% Human genetic differences are greater within populations (85%) compared to between (15%). From your everyday life, the data in Table 6.2, the disproportionate number of Black men in American prisons, you know that race is real and has profound impact on health. However, genomic DNA and many other rigorous scientific studies since the 1960s have all concluded that race cannot be defined by any collection of objective criteria such a DNA or phenotypes. Race is defined subjectively by individuals and cultures. From these judgements, people are treated differently which causes real and measurable consequences.

Answer 23

Ricettsia sp. is a type of aerobic, heterotrophic bacteria alphaproteobacteria which are thought to be the most common ancestor to mitochondria Cyanobacteria are the proposed ancestors to chrlorplasts.

Answer 24

The genotype of the VKORC1 is a better predictor of effective doses of warfarin, compared to race. Races with the same genotype should be given the same amount of warfarin. Not every individual within a race will have the same genotype.

Answer 25

The Yoruba and Luhya samples have mostly the ancestral and darker SNP, G. The Maasai samples have about the same number of homozygous G as heterozygous genotypes. All three Chinese samples have more than 50% homozygous G despite their skin tones being much lighter than the Maasai. GIH and CEU both have AA more than 50%. They likely have lighter skin color, even in India. These apparent contradictions underscore the complexity behind human skin tone genetics.

Answer 26

Eukarya share a more recent common ancestor with archaea, so are more closely related to archaea than bacteria.

Answer 27

At some point an ancient archaea (maybe) engulfed a bacteria that could use oxygen to help make energy. That bacteria did not die and eventually became the mitochondria. Another eukaryote that had a mitochondria eventually ate a cyanobacteria that could perform photosynthesis. This also did not die and become the chloroplasts

Answer 28

Transcription, translation, replication from Archaea ATP production from bacteria Metabolism, detox, ion homeostasis, both ring of life,” represents more accurately how the three domains evolved due to endosymbiosis. Bacteria and archaea “merged” to form Eukaryotes.

Answer 29

A shows mitochondria. Which is found in all eukaryotes, including plants. Mitochondria generates ATP for cells B. shows chloroplasts wich is found in plants and algae and other photosynthetic eukaryotes. Chloroplasts turn light energy into chemical energy (sugars). Endosymbiosis refers to the process by which formerly small bacteria that began living within larger cells. Both organelles have two outer membranes. The inner membranes of both organelles have enzymes and transport systems that are homologous to those found in the plasma membranes of living prokaryotes. Each of these organelles contains circular DNA molecule that, like the chromosomes of bacteria, is not associated with histones or large amounts of other proteins. These organelles also have the machinery (ribosomes, etc.) needed to transcribe and translate their DNA into proteins.

Answer 30

The bootstrap process is designed to reveal how robust and reliable the depicted relationships are in the evolutionary tree. Higher bootstrap values means you should have more confidence in that evolutionary relationship because even after randomization and resampling that relationship was retained

Answer 31

Out of Africa Hypothesis posits that all modern humans (Homo sapiens) originated from a single population in Africa and then migrated to other parts of the world, replacing local archaic human populations such as Neanderthals and Denisovans Based on this tree african and non-african populations share a common ancestor that was African. This supports the out of Africa hypothesis. African populations have greater genetic diversity among populations, which is indicated by the longer branch lengths within African populations. This greater genetic diversity indicates a longer period of genetic evolution there. All non-African populations show a more recent, smaller subset of this genetic diversity, suggesting they are descendants of a population that migrated out of Africa. The out-of-Africa theory has been validated many times by these data and many more. Some of the MRCA of west Africans and people currently living outside Africa migrated west where their descendants live today, whereas others migrated east out of Africa. Collectively, the two San individuals have more differences in their mtDNA which is revealed by the longest cumulative vertical distance between them and their most similar match of #5, the Hausa individual. Considering only one person, Ibo #12 is the most different compared to Ibo #11 The MRCA at the branch marked by 98 (the left one) represents the shared ancestors between current Africans and all the current non-African. The bootstrap value of 98 indicates a very high confidence in this branchpoint (98%)

Answer 32

If we assume that the Black African immigrants and African Americans share much of their DNA, then it seems environmental differences are the major factor.

Answer 33

The skin color alleles evolved before H. sapiens became a separate species (200,000 – 300,000 years ago), and before a subset of humans migrated out of Africa about 100,000 years ago. Only the SLC24A5 SNP evolved after a subset of H. sapiens migrated out of Africa. The oldest known fossils of our species suggest that Homo sapiens appeared in Africa sometime between 195,000 and 160,000 years ago.

Answer 34

The evolutionary history of a group of organisms can be represented in a branching diagram called a phylogenetic tree. Polar bears are equally related to these two species because polar bears share the same common ancestor with both of these two species.

Answer 35

Figure C. Trees a and b show that taxon C and D share the most recent common ancestor, and that clade is most closely related to the B lineage. However, the C tree suggests that C and B share the most recent common ancestor, and that clade is closely related to the lineage leading to D.

Answer 36

There is a genetic variation in each race, especially for the VKORC1 promoter genotypes. GG, GA and AA are best for determining effective treatments, not race. Race-based medicine assumes all individuals within a race are the same genetically. We know that is not the case.

Answer 37

No, the White immigrant mothers give birth to heavier children than the Black immigrant mothers. However, with the small sample size of 194 and the lack of statistical measure, we cannot be sure if these two averages are significantly different or not. The G3 grandchildren of immigrants have very different outcomes. The White immigrants have a significant increase in birth weights whereas the Black immigrant grandchildren have a decrease in birth weight. Only Black immigrating to American show a decline in birth weights for children born of mothers who were raised in America. Therefore is it highly unlikely that genetics is the major factor for the decline. It is much more likely that systemic racism and its effects as seen in Table 6.2 is the major factor leading to this decline.

Answer 38

chimpanzees are our closest living relative meaning that we share a common recent ancestor with chimpanzees, but we did not evolve from them. We evolved from a common ancestor that is now extinct and was not a chimp or a human. We have been evolving independently for the last 6-7 million years. These trees are the same. Humans closest relative are chimps followed by gorillas, then orangutans, then gibbons. It’s the same in both trees.

Answer 39

A. Primary structure: Chain of amino acids with a unique sequence. Polypeptide chain. B. Secondary structure: α helix or β pleated sheet: Coils and folds resulting from the hydrogen bonds between polypeptide backbone C. Tertiary structure: Overall shape (3D shapre) of the polypeptide resulting from interactions between the side chains (R groups) of the various amino acids. All proteins have primary, secondary, and tertiary structure D. Quaternary structure: Overall protein structure that results from the aggregation of multiple tertiary structure proteins (hemoglobin is a great example)

Answer 40

Both are different mechanisms by which molecules interact with enzymes or receptors to regulate their activity Allosteric modulators are ligands that bind to a protein, usually away from the functional site, which alters the protein's shape and its function A second way of altering the shape of a protein is by covalent bonding. The most frequent reaction of this type is accomplished by the addition of a phosphate group, phosphorylation. Any enzyme that mediates protein phosphorylation is called a protein kinase. These enzymes catalyze the transfer of phosphate from a molecule of adenosine triphosphate (ATP) to a hydroxyl group present on the side chain of certain amino acids.

Answer 41

The figure compares two polysaccharides, starch and cellulose. They are both long chains of glucose molecules, but starch has a 1-4 Alpha- bonds while, cellulose has a 1-4 beta bond. Due to the difference in bond angle, our enzyme amylase cannot digest cellulose but can use starch for energy. Starch is on the left and cellulose is on the right. Humans enzymes digest starch by hydrolyzing its alpha linkages; however, these enzymes cannot hydrolyze the beta linkages of cellulose because of the distinctly different shapes of these two. Some microorganisms can digest cellulose, such as bacteria in a cow as well as some fungal species. Cellulose, which is found in all plant cell walls!

Answer 42

The cytoskeleton is a network of fibers extending throughout the cytoplasm. The cytoskeleton gives mechanical support to the cell to help maintain its shape, provides anchorage for many organelles and cytosolic enzymes, and facilitates vesicle traffic by providing a scaffold upon which motor proteins can “walk.” Microvilli are the surface in which proteins are embedded that bring nutrients into intestinal cells for delivery throughout your body. By having a wavy surface, each intestinal cell can have more import proteins on its surface and thus bring in more nutrients without requiring the cell to become substantially larger.

Answer 43

Scientists wanted to understand how the endoplasmis reticulum formed. They found that microtuble tracks are used by a motor protein called kinesin to pull membranes from the nucleus to form many tubes. Kinesin moves along each microtuble track and can change directions easily along each track. Via this process the volume of the vesicle plus the tubes remains essentially unchanged, but the total surface area grows rapidly as the tubes are pulled from the vesicle

Answer 44

lipid composition of the large experimental vesicle, changed the diameter on the new tube being drawn out by kinesin. Three different lipid compositions required different amounts of force to pull the tubes. The three different tubes of membrane also had different diameters depending on the lipid.

Answer 45

Lipid vesicles spontaneously adopt varied shapes. Rigid lipids were labeled blue, and more fluid, relaxed lipids were labeled red. Lipid composition can determined membrane shape. Highlighting form follows function.

Answer 46

A represents the hydrophobic amino acids. They are all non-polar R groups. Many Cs and Hs B represents the hydrophilic amino acids. They have many O, N, S, in their side chain. All all polar or some kind of charged molecules. Hydrophobic amino acids (only Cs and Hs) would be folded inside of the protein to avoid touching water. During the folding (tertiary structure) the hydrophilic amino acids (charges, N, O, S) will be placed on the surface of the protein, in contact with water. If a hydrophilic amino acid replaced a hydrophobic, the protein would not fold the same and it would likely lose its functionality. If a hydrophilic amino acid replaced a hydrophilic, the protein would likely fold the same and it would remain functional.

Test 2 Flashcards

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