BIOL 2111 Study Guide - Final Guide: Apical Ectodermal Ridge, Maternal Effect, Limb Bud

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yellowwildebeest396

15 Dec 2017

School

University of Windsor

Department

Biological Sciences

Course

BIOL 2111

Professor

Steven Ralph

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Document Summary

60 multiple choice (30 from old stuff [chapters 2-12 and 14-17] and 30 from chapters 13, 18, Learning objectives: (the learning objectives are in bold) Key terms to know: totipotent cells, cell fate, developmental field, morphogens, organizers. Understand the role of hox genes as master switches in animal development. Totipotent cells are cells in a zygote that are able to develop into any cells initially (they are very potent). An example of these types of cells are stem cells. Cell fate is a term referred to the destiny of a cell, where they go in a procedure to differentiate into different cell types that are unable to go back to their previous form afterwards. Development field refers to a set of cells that interact with each other to form a particular structure (tissue, organ and limb) Morphogens are molecules (gene products, for example) from specific cells that tell other cells to follow a specific fate.

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Summary

please!

Multipotent versus restricted

Morphologically detectable neural crest cells usually are first observed as the cells individualize and delaminate upon emigration from the neural tube, following their epithelial to mesenchymal transition (EMT), in which they convert from a tightly adherent sheet of cells to a dispersed and more individual mesenchymal population. Prior to EMT, however, it is difficult or impossible at most axial levels and in most species to distinguish presumptive neural crest cells from cells that will form dorsal neural tube derivatives. However, there are exceptions, such as a subpopulation of cranial neural crest cells in chick and mouse that appears to be set aside and morphologically distinct at midbrain levels. In addition, some species such as axolotl have a clearly segregated population of neural crest cells that exists as a ridge on the dorsal neural tube.

A long-standing debate in the neural crest literature has been whether neural crest cells are multipotent and/or restricted in their developmental potential. In other words, can a single neural crest precursor form only one type of derivative or are the cells multipotent and able to produce multiple derivatives. Single cell lineage experiments (Bronner-Fraser and Fraser, 1988), in which individual cells within the chick dorsal neural tube are labeled with vital dye, show that some of the labeled clones contribute to multiple differentiated cell types in the periphery, including melanocytes, sympathetic and sensory ganglion cells. Thus, the original precursor was âmultipotentâ in its developmental potential to form neural crest derivatives. In addition to neural crest derivatives, single dorsal neuroepithelial cell also give rise both to migrating neural crest cells and cells that remain in the dorsal neural tube, such as roof plate cells and dorsal sensory neurons and/or interneurons. This suggests a shared lineage between the neural tube and neural crest, at least at this stage. However, labeling migrating neural crest cells in vivo also produced clones that could contribute to more than one neural crest lineage (Fraser and Bronner-Fraser, 1991), again supporting the idea that some of the migrating population retained multipotency.

Clonogenic culture of neural crest cells cultured shortly after their emigration from the neural tube definitely shows that many early migrating neural crest cells are multipotent in vitro as well (Baroffio et al., 1988, Calloni et al., 2007, Calloni et al., 2009, LeDouarin et al., 2008a, LeDouarin et al., 2008b, Sieber-Blum and Cohen, 1980 and Stemple and Anderson, 1993). Exposure to different growth factors can profoundly influence their lineage decisions (e.g. Lahav et al., 1998). Furthermore, they have a capacity for self-renewal, at least for a few cell divisions (Stemple and Anderson, 1993 and Trentin et al., 2004).

The fact that individual neural crest cells can form multiple derivatives has led to the idea that they have stem cell properties. Stem cells are defined as individual progenitor cells that can generate one or more specialized cell types. A cardinal feature of stem cells is their ability to self-renew, that is, to divide so as to give rise to at least one daughter cell that maintains the multipotent character of its parent. The fact that cloned neural crest cells have a limited ability to self-renew has led to the idea that they are stem-like (progenitors) cells rather than true stem cells. Interestingly, however, neural crest stem cells can be derived from adult tissues (Fernandes et al., 2008 and Shakhova and Sommer, 2010; see Chapter Dupin and Sommer), suggesting that they can remain quiescent for long periods of time or maintain long term self-renewal ability when left in situ.

The presence of some multipotent neural crest precursors cannot, however, rule out the possibility that other precursors may be more restricted in their developmental potential. In fact, experiments in zebrafish suggested that neural crest cells contribute to different sets of derivatives accordingly to their migration order (Raible and Eisen, 1994). However, if the leader cell was ablated, the next cell in line took up the fate that would have been filled by the ablated cell (Raible and Eisen, 1996). Similarly, early migrating neural crest cells normally exhibit a broader range of derivatives than later migrating cells; however, when the early population is ablated and replaced by late migrating cells, the late migrating cells assume a broader developmental potential than that prescribed by their normal fate (Baker et al., 1997). This raises a very important issue: that developmental potential is greater than or equal to a cell's normal fate. Only by challenging the cell by putting it into a new environment can one test for restriction of cell fate. This is best exemplified by experiments in which the potential of neural crest populations was challenged by performing heterotopic transplants between different axial levels (LeDouarin and Teillet, 1974), such as exchanging cranial and trunk, or vagal and trunk populations. The results demonstrate a combination of flexibility in cell fate and some axial level-autonomous characteristics. For example, cranial neural crest cells normally make cartilage and bone of the face whereas trunk neural crest cells do not. Transplantation of cranial neural folds to the trunk results in production of many normal trunk derivatives, as well as the formation of ectopic cartilage nodules (Le Lievre et al., 1980 and LeDouarin and Teillet, 1974). Conversely, transplantation of trunk neural folds to the head results in contributions to cranial neurons and glia of cranial ganglia, but not to cartilage, although some connective tissues and pericytes derive from this graft (Nakamura and Ayer-le Lievre, 1982). This reveals some flexibility in fate, but a more limited ability to form skeletal derivatives (LeDouarin et al., 2004). However, trunk neural crest cells can form cartilage in vitro under appropriate culture conditions (Calloni et al., 2007 and McGonnell and Graham, 2002). Because challenging prospective neural crest fate is a difficult experiment, it is much easier to prove multipotency than restricted cell fate, leaving the question of whether or not there are lineage-restricted neural crest precursors still open to debate (see Krispin et al., 2010).

Which of the two major categories of the chemical reactions in photosynthesis is oxygen the INDIRECT product?

Glycolysis

Oxidative phosphorylation

Both light and dark

Light independent phase (LIP)

Light dependent phase (LDP)

You have a stomach flu characterized by vomiting. Which of the following systems is most responsible for the food in your stomach going the wrong way, e.g. vomiting? (Disregard this question and answer choice B)

Cardiac Muscle in the large intestine as discussed in class.

Smooth muscle in the gastrointestinal tract

Smooth muscle in the blood vessels

Skeletal muscle in the intestine

Proteins are made from which of the following smaller sub units?

Nucleotides

Amino acids that cannot enter the blood stream and go to cells

Monosaccharides

Fatty acids

Amino acids which can form new protein

Carbohydrates are digested in the gastrointestinal system into which of the following substances that is the smallest structure?

Polysaccharides that are produced by glucagon

Monosaccharides that are produced by insulin

Monosaccharides

Polysaccharide

Which of the following biomolecules has the longest digestion time? In other words, how long does it take for the biomolecule to be catabolized?

DNA

Lipid

Carbohydrate

Protein

You are sunburned after a long day at the beach. Which one is not an example of UV damage to your skin cells?

A mutation can occur in your ovaries

A mutation can occur in skin cell DNA that can lead to errors in transcription.

Errors can occur during DNA replication.

UV light can cause mutations in DNA of skins cells.

Thymine bases in your skin DNA bond with each other instead of across the double helix

This region, the ______________ (a) tells RNA polymerase where to bind to DNA while this region, the ______________ (b) tells RNA where to start transcription.

(a) promoter, (b) open reading frame

(a) start codon, (b) methionine

(a) promoter, (b) start site

(a) start site, (b) promoter

The genetic code is used to translate ______________ into ______________.

lipids, nucleotides

nucleotides,carbohydrates

nucleotides, lipids

nucleotides, amino acids

nucleosides, amino acids

Transcription of a gene has just completed. What are the next steps (in the correct order) to complete expression of that gene?

RNA polymerase makes a copy of DNA into mRNA.

mRNA is translated in the nucleus and ribosomal RNA moves into the cytoplasm.

Gene expression is completed after transcription.

mRNA moves into the cytoplasm and with tRNA they interact to form protein

Translation machinery moves into the nucleus and mRNA is translated into protein.

How is it that a mutation in DNA stored inside the nucleus of a cell can cause a disease affecting multiple organs?

This remains an unanswered question in science that scientists are still trying to figure out.

The mutated DNA is expressed in multiple cells through the process of transcription and translation, and the altered protein causes the disease wherever the DNA was expressed.

The mutated DNA is expressed in one cell and the altered protein travels to multiple organs to cause disease.

The mutated DNA is expressed and the mRNA takes the mutated information to other cells where the altered protein is made to cause disease in that organ.

The advantage of sickle cell anemia is which of the following?

It decreases the amount of oxygen in the blood cells so that mosquitoes carrying malaria will live

It decreases the amount of oxygen in the blood cells so that mosquitoe's blood form will die.

It allows the blood vessels to decrease the amount of blood going to the toes and feet.

There is none.

Which of the following is a purpose of cell division?

Cell reproduction

Growth

Repair

All of these

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.

Lysosomes

Endosomes

Peroxisomes

Nucleosomes

Biologists cannot possibly study all living species. Instead, they try to understand cell behavior by studying a select subset of them. Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies?

rapid rate of reproduction

all of the above

ability to grow under controlled conditions

amenability to genetic manipulation

By definition, prokaryotic cells do not possess __________.

ribosomes.

a nucleus.

membrane bilayers.

replication machinery.

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a microscope is limited by the __________ of light.

intensity

absorption

wavelength

filtering

Choose the phrase that best completes this sentence: Microtubules ____________ and are required to pull duplicated chromosomes to opposite poles of dividing cells.

generate contractile forces

can rapidly reorganize

are found in especially large numbers in muscle cells

are intermediate in thickness

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton?

cell division

cell motility

vesicle transport

membrane support

DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA?

It contains thymine.

It has 5'-to-3' directionality.

It is single-stranded.

It contains uracil.

Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they ____________________.

prevent additional bonds from being formed with the bonded atoms.

limit the rotation of the bonded atoms.

create a new arrangement of electron shells.

change the reactivity of the bonded atoms.

Drosophila melanogaster is a/an __________. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model.

mammal

amphibian

bird

insect

10.

If the isotope 32S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons will the isotope 35S have, respectively?

16, 19, 17

16, 19, 15

16, 19, 16

16, 20, 15

11.

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?

cell

organelle

protein

DNA

12.

Macromolecules in the cell can often interact transiently as a result of noncovalent interactions. These weak interactions also produce stable, highly specific interactions between molecules. Which of the factors below is the most significant in determining whether the interaction will be transient or stable?

the concentration of each molecule

the size of each molecule

surface complementarity between molecules

the rate of synthesis

13.

Many of the mechanisms that cells use for maintenance and reproduction were first studied at the molecular level in bacteria. Which bacterial species had a central role in advancing the field of molecular biology?

E. coli

S. pombe

C. elegans

D. melanogaster

14.

Many types of cells have stores of lipids in their cytoplasm, usually seen as fat droplets. What is the lipid most commonly found in these droplets?

cholesterol

isoprene

triacylglycerol

palmitic acid

15.

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are __________________.

anaerobes.

viruses.

parasites.

endosymbionts.

16.

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of material âburnedâ and the form of energy produced during cellular respiration?

17.

Polar covalent bonds are formed when the electrons in the bond are not shared equally between the two nuclei. Which one of these molecules contains polar bonds?

BIOL 2111 Study Guide - Final Guide: Apical Ectodermal Ridge, Maternal Effect, Limb Bud

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