aishkadao123

How do microtubules contribute to the asymmetric distribution of molecules during development? Drosophila embryos are treated with colchicine, a chemical that depolymerizes microtubules. What general effect will this have on the distribution of bicoid and oskar in the embryo?

Colchicine is a chemical that disrupts mitosis by inhibiting microtuble polymerization. Describe an experiment that determines the effects of colchicine on meiosis. Include the terms: spindle fiber, synapsis, nondisjunction, and aneuploidy. Draw and label one figure summarizing at least one part of the experiment.

Use the dropdown menu to match the following descriptions with the correct term.

In its presence microtubules will depolymerize

colchicine , BiP, latrunculin, Arp 2/3 complex

Which of the above participates in the docking of vesicles with target membranes?

colchicine , BiP, latrunculin, Arp 2/3 complex

Which of the above mediates the folding of proteins and the recognition of unfolded proteins?

colchicine , BiP, latrunculin, Arp 2/3 complex

Which of the above will cause branches to form on the actin cytoskeleton?

colchicine , BiP, latrunculin, Arp 2/3 complex

A scientist observes the motion of a certain type of vesicle around the cell. She notices that vesicle movement ceases when colchicine is added to the culture medium. What conclusion can she draw? (5 marks)

In a population of fish with an initial size of 100 individuals youmeasure 65 births and 25 deaths over the course of a year. For thispopulation r would equal.

A)
45
B)
.45
C)
.40
D)
40
E)
None of the above

The .......... species concept holds that species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.
select one:
a) Darwinian
b) biological
c) morphological
d) linnaean
e) natural populations

The membrane receptor Patched is a negative regulator of Hedgehog signaling, where Patched acts to halt Hedgehog signaling. It has been shown that high levels of Hedgehog signaling in a cell causes an increase in Patched expression within that cell. Is the impact of high levels of Hedgehog an example of negative or positive feedback? Explain your choice.

Which of the following pairs are mismatched?

a) helicase- unwinds DNA

b) DNA ligase- seals DNA molecules

c) DNA gyrase- primes RNA template

d) DNA polymerase I- proofreading

what could explain the migration of a protein in a gel at 100kD, when by DNA sequencing, the protein should be 60kD?

You would expect a halotolerant microbe to grow best on the 0.5% NaCl plate but possibly grow on the 5% NaCl plate.

Select one:

True

False

1) What is a tumor?

A) List and briefly describe 5 characteristics of a tumor (or tumor cells) as contrasted with the corresponding normal tissue (or cells).

B) What is the defining characteristic of a malignant tumor as opposed to a benign tumor?

C) How do these characteristics support the theory that carcinogenesis is a multistage (i.e. that more than one step occurs during the development of cancer)? Can you suggest a way that one one genetic (or epigenetic) alteration could lead to multiple characteristics of a tumor (hint: consider pleiotropy):

Explain in details the 3 characteristic of occupational carcinogens namely: 1) genomic 2) electrophilic 3) genotoxic

Microbiology: A Systems Approach 5^th Edition. Cowan et al. 2017. McGraw-Hill Publishing.

Can be any pathogen

1. What is the relationship between the genetic defect in CF and the microbiological complications associated with the disease? Why are CF patients predisposed to pulmonary infections?

Microbiology

A nurse stops by a new patient’s room and observes a sign outside the door indicating that a disposable mask and gown should be worn in addition to latex gloves when caring for this patient. What are the two broad categories of patients that would require this extra step, and who is this gear designed to protect in each category?

Explain how clonal selection contributes to the development and expansion of antigen specific lymphocytes that do not respond to self.

Glycans that are conjugated to lipids or proteins play roles other than as energy store in cells. With use an example for each, suggest the cellular localizations of glycocolipids and glycoproteins and biological functions of the glycan moieties of these glycoconjugates.

I have just an intuition that the carbohydrate part ofglycoproteins help them to fulfil those tasks like in plasmamembranes. You can also get many more receptors if you can usecarbohydrates too.

For instance, glycoproteins are necessary in recognising whiteblood cells. Antibodies are examples of glycoproteins. So they playa crucial role in our innate and adaptive immunity: MHC interactionwith T cells in adaptive immunity. Other examples: necessary inplatelet aggregation and adherence, components of zona pellucidaand connective tissue. Some hormones are also glycoproteins sonecessary in humoral adaptive immunity: FSH, LH, TSH and EPO.

But why glycoproteins are "better" than proteins withoutcarbohydrates moiety in fulfilling biological tasks?

I still see that both are important, but why the one is betterthan the other one.

In other words: Are there any biological tasks that onlynon-glycoproteins can fulfil, not glycoproteins? Arenon-glycoproteins necessary in some essential biological tasks?

I think the answer to the last two questions is "yes", so whywould one say that glycoproteins are better in fulfillingbiological tasks than non-glycoproteins.

GIve the ploidy (haploid diploid or triploid) of the following parts of the life cycle:

sperm nuclei-

zygote-

cells which make up the cotyledon cells of endosperm after double fertilization-

each polar nuclei

sepal cells of the flower

endosperm

pollen grain tube nucleus

cells which make up the ovary

cells which make up the seed coat

leaves on the mature plant

cells which make up the fruit

megaspore

microspore mother cell

Which of the following cells does not have the same ploidy level as the megaspore and microspore? Select one: a. Antipodal cell before fertilization b. Endosperm cell after fertilization c. Generative cell d. Synergid e. Tube cell

Ultraviolet (UV) visual sensitivity in animals has implications for mate choice, social signaling, prey detection, and foraging in general. Research into the genetic basis of the ability to detect ultraviolet light reveals that:

Select one:

a. this ability is the product of complex interactions among many gene loci.

b. sensitivity to UV appears to involve a single amino acid substitution in a visual pigment molecule.

c. the relative rarity of UV sensitivity among animals is attributable to the fact that multiple modifications of the visual pigment molecule promoting UV sensitivity are necessary to allow the detection of high-energy light.

d. UV-sensitive organisms are all descended from a common ancestor.

e. where genes coding for visual pigment molecules become integrated, they can vastly extend the spectrum of the photosensitive pigment produced.

What happens to a lizard's metabolic rate when the temperature increases 10 Celcius?

A.) The metabolic rate stays constant B.) The metabolic rate approximately doubles C.) The metabolic rate approximately triples D.) The metabolic rate approximately quadruples

why is including age structure in models important to determine population growth?

Which three major proteins are found in egg white? Out of these three proteins, which protein requires lower ionic strength and higher ionic strength to precipitate out?

1) Which of the following about combinatorial control is false?

Bicoid protein is encoded by an autosomal gene and is essential to the development of the anterior part of Drosophila embryos. In the absence of bicoid protein embryos are headless! You cross a male fly in which both bicoid alleles are non-functional (bcd^-/bcd^-) to a female that is heterozygous for the mutant allele (bcd^-/bcd⁺). In case you’re wondering, they both have heads.

a) How is this even possible: how does this mutant male have a head?

b) What fraction of embryos from this cross will have heads?

GMO

What possible negative effects could there be on the environment?

Might economic pressures (for example, in countries where a significant proportion of the population is food-insecure) outweigh the environmental concerns in some countries but not others?

What are current regulations in U.S. about production and labeling of GMOs? What are current regulations in other countries?

How will controlling soil erosion address the problem of widespread food insecurity? discuss 2 or 3 other possible actions that can be taken to reduce the number of people who are currently food insecure. How can the creation and maintenance of roads help alleviate the problem?

The removal of top soil by water or wind is called

A Soil erosion

B Soil wash

C Silting of soil

D Soil creep

In one complete sentence explain why PCR is a chain reaction.

What is monoclonal antibody? How do you use a monoclonal antibody to detect if a patient is infected by specific strain of flu virus by ELISA? If a patient got a flu shot against this strain of flu virus three weeks ago, how will that affect your result?

Which cell has the smallest electrical potential across its membrane?

a.A cell with a membrane potential of -100 mV

b.A cell with a membrane potential of +40 mV

c.A cell with a membrane potential of +4 mV

d.A cell with a membrane potential of -6 mV

How are the underlying assumptions between the logistic model and the lotka-volterra equations different