UW Bio

Question 1

interferons

Answer 1

Interferons are categorized as cytokines, small proteins that are involved in intercellular signaling. Interferon is secreted by cells in response to stimulation by a virus or other foreign substance, but it does not directly inhibit the virus’s multiplication. Rather, it stimulates the infected cells and those nearby to produce proteins that prevent the virus from replicating within them.
interferons represent a large class of signaling molecules that act in both the innate and adaptive immune systems.

Question 2

Penetrance and Expressivity

Answer 2

Penetrance refers to the portion of offspring that express a genetic trait.
Expressivity refers to the range of symptoms observed (phenotypic) in individuals with a given genetic condition

Question 3

In an isolated population of 10,000 mice, 1,600 are homozygous for a Tlr4 defect. Assuming stable allele and genotype frequencies, how many mice are heterozygous for a Tlr4 defect?

Answer 3

The frequency of mice homozygous for the mutated allele (q2) is 1,600/10,000, or 0.16. Therefore, q is the square root of 0.16, or 0.40, and this value can be used to calculate p: p = 1 − 0.40 = 0.60
2pq = 2(0.60)(0.40) = 0.48
(0.48)(10,000) = 4,800 mice

Question 4

SDS-PAGE

Answer 4

separates PROTEINS by SIZE only

1. ) samples heated wit SDS ( a denaturing agent) that coats proteins a negative charge consistent with its size and unfolds it into linear chain
2. ) since proteins are smaller then DNA they are loaded onto highly cross linked polyacrylamide gel instead of arose gel
3. ) electric current applied and proteins travel towards anode (+)
4. ) bands stained with coomassie blue

Question 5

telemeres

Answer 5

Repetitive sequences that get shorter after each round of division. Made up of heterochromatin because they are not actively transcribed similar to areas close to the centromere which are also heterochromatin better not transcribed

Question 6

Erythropoietin production

Answer 6

kidneys produce Erythropoietin a hormone that signals the bone marrow to increase red blood cell (erythrocyte) production

Question 7

calcitriol

Answer 7

produced in kidneys/ increase calcium levels

Question 8

Kidney function

Answer 8

Control of extracellular fluid volume & regulation of blood pressure via the renin-angiotensin system
Regulation of osmolarity (ie, excretion or retention of water)
Regulation of ion concentration (Na+, K+, Ca2+) by balancing dietary ion intake with urinary excretion
Regulation of pH via bicarbonate buffer system (excretion/retention of HCO3− and H+)
Excretion of waste (creatinine, ammonia, urea, foreign substances)
Production of renin (enzyme involved in blood pressure regulation) & hormones (erythropoietin for erythrocyte production & calcitriol for increased Ca2+ levels)

Question 9

leukocytes

Answer 9

WBC

Question 10

Germ Layers

Answer 10

Endoderm (innermost layer): gives rise to accessory digestive organs (eg, liver, pancreas) as well as to the lining (epithelium) of the digestive and respiratory tracts.

Mesoderm (middle layer): gives rise to the circulatory system, the musculoskeletal system, and parts of the urinary and reproductive systems.

Ectoderm (outermost layer): gives rise to the nervous system (neurulation) and develops into the integumentary system, which includes hair, skin, nails, and the lining of the mouth, nostrils, and anus.

Question 11

genetic drift

Answer 11

Bottlenecks (due to environmental events or human action) greatly reduce the genetic diversity of a population. Consequently, the smaller population of cheetahs has a reduced ability to buffer the negative impacts of random changes in allele frequencies (genetic drift) that may result in extinction.

Question 12

inbreeding vs outbreeding

Answer 12

Inbreeding results in decreased heterozygosity (genetic diversity), reduced fecundity, and reduced fitness. Species that mate with nonrelatives (outbreed) increase their fitness because the introduction of new genetic material results in increased heterozygosity.

Question 13

Nuclear enveloped breaks/reforms

Answer 13

breaks in prophase and reforms in telephase

Question 14

Spermatogenesis

Answer 14

Spermatogenesis is a process in which male gametes (sperm) are produced and occurs in the seminiferous tubules of the testes. Spermatogonia undergo meiotic division and become spermatocytes, which then become spermatids when meiosis is completed. Spermatids then mature into spermatozoa (mature sperm) through a series of morphological changes.

Spermatogonium, spermatocyte, spermatid, spermatozoon

Question 15

native gel in electrophoresis

Answer 15

no reducing agents or denaturants were used, samples maintain there structure

Question 16

origins of replication in prokaryotes vs eukaryotes

Answer 16

prokaryotes have circular DNA with a single origin of replication (Ori) in the cytoplasm, whereas eukaryotes have linear DNA with multiple origins of replication in the nucleus.