Description : Multiple checkpoints in the eukaryotic cell cycle ensure that division occurs only after sufficient growth and faithful DNA replication, and only when favorable conditions exist. Of the many proteins involved in ... CDKs) are among the most important. How do CDKs function to control the cell cycle?
Last Answer : CDKs phosphorylate various protein substrates that are required for cell cycle progression. Some of the important substrate proteins that CDKs phosphorylate include condensin proteins, which are essential ... which form a stabilizing network under the nuclear membrane that assembles during mitosis.
Description : A cell that is missing lysosomes would have difficulty doing what? (A) Digesting food (B) Storing energy (C) Packaging proteins (D) Moving cytoplasm
Last Answer : (A) Digesting food
Description : Typically proteins do not work in their simple amino acid chain structure but instead fold and form shapes that help in their function. Which of the structures is described as being in alpha helices and beta sheets?
Last Answer : Secondary Protein Structure
Description : What is Tightly wound bundles of DNA are called?
Last Answer : What is the answer ?
Description : What are the primary and the secondary constrictions of a chromosome ?
Last Answer : What is the other name given to the secondary constriction? Primary constriction is the narrower region of a condensed chromosome where the centromere, the structure that unites identical chromatids, is located. ... can be one or more in chromosome) is called nucleolus organizer region (NOR).
Description : How the chromosome region where the centromere is located is called ?
Last Answer : How are chromosomes classified in relation to the position of their centromere? The chromosome region where the centromere is located is called primary constriction. In microscopic view ... constriction the chromosomes are classified as telocentric, acrocentric, submetacentric or metacentric.
Description : How are the concepts of chromosome ?
Last Answer : chromatin and chromatids related? In which phase of the cell cycle does DNA duplicate? Chromatin is a set of filamentous DNA molecules dispersed in the karyoplasm forming euchromatin and heterochromatin ... chromosomes (and not only one). Cell Nucleus Review - Image Diversity: chromatids
Description : What is the relation between the concepts of chromatin and chromosome ?
Last Answer : Are euchromatin and heterochromatin part of chromosomes? Every filament of chromatin is a complete DNA molecule (a complete double helix), i.e., a complete chromosome. A DNA molecule may form ... thus both are part of chromosomes. Cell Nucleus Review - Image Diversity: chromosome structure
Description : At the beginning of which phase of mitosis does each duplicated and condensed chromosome consisting of two identical sister chromatids align along the cell equator?
Last Answer : Metaphase
Description : A chromosome whose centromere lies at one end. (A) Sum-metacentric (B) Metacentric (C) Telocentric (D) Acrocentric
Last Answer : (C) Telocentric
Description : A chromosome with the centromere located very close to one end so that the shorter arm is very small is termed as (A) Telocentric (B) Sub-telocentric (C) Acrocentric (D) Both B and C
Last Answer : (D) Both B and C
Description : Chromosome with equal arms is called (A) Metacentric (B) Sub-metacentric (C) Acrocentric (D) Telocentric
Last Answer : (A) Metacentric
Description : Each chromosome consists of two identical (A) Genes (B) Nuclei (C) Chromatids (D) Bases
Last Answer : (C) Chromatids
Description : In many types of cancer, proteins that are crucial regulators of the cell cycle are often mutated and cannot function correctly. This leads to the evasion of apoptosis and to the loss of control of cell ... protein named p53. What is the normal function of p53 that is lost when it is mutated?
Last Answer : Normally, p53 senses DNA damage and acts as a transcription factor for checkpoint control genes.
Description : What are the main cytoplasmic structures present in animal cells ?
Last Answer : The main cytoplasmic structures of the cell are the centrioles, the cytoskeleton, lysosomes, mitochondria, peroxisomes, the Golgi apparatus, the endoplasmic reticula and ribosomes. Cell Structure Review - Image Diversity: cell organelles
Description : What are the main structures within the cell nucleus ?
Last Answer : Within the cell nucleus the main structures are: the nucleolus, an optically dense region, spherical shaped, where there are concentrated ribosomal RNA (rRNA) associated to proteins (there may be ... cell interphase; the karyotecha, or nuclear membrane, the membrane that delimits the nucleus.
Description : Which of the following organelles or structures is found in both plant and animal cells? (A) Central vacuole (B) Tonoplast (C) Cell wall (D) Peroxisomes
Last Answer : (D) Peroxisomes
Description : How do the rough endoplasmic reticulum and the Golgi apparatus act in the production and releasing of proteins ?
Last Answer : The rough endoplasmic reticulum has in its outer membrane numerous ribosomes, structures where translation of messenger RNA and protein synthesis occur. These proteins are stored in the rough endoplasmic reticulum ... exocytosis) in the right place and its content is liberated outside the cell.
Description : Without saturation of transport proteins and under same concentration gradient how can the speed of simple diffusion be compared to the speed of facilitated diffusion ?
Last Answer : The action of facilitator proteins in facilitated diffusion makes this type of diffusion faster than simple diffusion under equal concentration gradients of the moved substance.
Description : In order to function, CDKs must interact with members of a separate family of proteins named the cyclins. Do individual cyclins remain associated with the same CDKs throughout the entire cell cycle?
Last Answer : No. Separate cyclins interact with specific CDKs only during defined periods of the cell cycle.
Description : What are heterotrimeric G proteins?
Last Answer : G proteins with three different subunits, designated as alpha, beta, and gamma. Alpha and gamma subunits attach to the plasma membranes via lipid anchors. In the absence of a signal, the entire GDP ... alpha subunit is replaced by GTP, and the GTP-bound alpha subunit and beta-gamma dimer dissociate.
Description : What are G proteins?
Last Answer : G proteins are proteins that can bind guanosine triphosphate (GTP) and guanosine diphosphate (GDP). G-proteins function as switches; GTP-bound G-proteins are active whereas GDP-bound G-proteins are inactive.
Description : True or False: The vast majority of mitochondrial proteins are synthesized from genetic information encoded in the mitochondrial genome.
Last Answer : False. Most mitochondrial proteins are synthesized from nuclear genes and then transported into the mitochondria through the presence of a signal sequence.
Description : Name the organelle that contains high levels of hydrolases and is responsible for digestion of proteins, sugars, nucleic acids and lipids.
Last Answer : Lysosomes
Description : Describe how proteins that are synthesized in the endoplasmic reticulum (ER) are transported to their final destination.
Last Answer : Proteins that are synthesized in the ER have a signal sequence that directs them to their target destination. Soluble proteins are carried inside the lumen of vesicles. Cargo-bearing vesicles ... lysosomes or plasma membrane. Vesicles that have released their cargo return via the reverse direction.
Description : Name the type of proteins that work to catalyze metabolic reactions or can modify other proteins to switch their activity on or off.
Last Answer : Enzymes
Description : What is the function of proteins like microtubules and actin filaments?
Last Answer : Give structure to cells.
Description : Metabolism is carried out by a large class of proteins that decrease the activation energy required for chemical reactions inside a cell. Therefore they only facilitate reactions that would naturally occur at a much slower rate. What is the name of these proteins that speed up biochemical reactions?
Description : Biochemically the ribosome consists of _______________ and some 50 structural . (A) mRNA, Carbohydrates (B) tRNA, lipids (C) mRNA, Proteins (D) rRNA, Proteins
Last Answer : (D) rRNA, Proteins
Description : What is the main cell organelle involved in cell digestion ?
Last Answer : What are the properties of that organelle that enable it to the task? The organelles responsible for intracellular digestion are the lysosomes. Lysosomes are vesicles that contain digestive enzymes ... digested and then digestion takes place. Cell Digestion Review - Image Diversity: lysosomes
Description : These are involved in conversion of fats to carbohydrates by oxidation of fats. (A) Peroxisomes (B) Microsomes (C) Glyoxisomes (D) Phagosomes
Last Answer : (C) Glyoxisomes
Description : SER is abundant in cells that are involved in (A) Lipid metabolism (B) Protein metabolism (C) Glucose metabolism (D) Calcium metabolism
Last Answer : (A) Lipid metabolism
Description : During transcription, do both strands of DNA get transcribed into a double stranded RNA molecule?
Last Answer : No. RNA is single stranded and is transcribed from only one of the DNA strands. DNA replication does make copies of both strands.
Description : During which period of interphase does DNA replication take place?
Last Answer : S phase
Description : The structure of DNA is a double helix formed by two strands of DNA sequence. This sequence consists of 4 different nucleotides- Adenine, Thymine, Cytosine and Guanine. How do the nucleotides on one strand interact with the nucleotides on the second strand to maintain the helical shape of DNA?
Last Answer : Complementary Base Pairing. Adenine complementary base pairs with Thymine and Guanine complementary base pairs with Cytosine.
Description : In a eukaryotic cell, what separates DNA from the protein translation machinery in the cytoplasm?
Last Answer : The nuclear envelope.
Description : Which of the following would you NOT find in a bacterial cell (A) DNA (B) Cell membrane (C) Golgi apparatus (D) Ribosomes
Last Answer : (C) Golgi apparatus
Description : There are a multitude of various dressings available. Which of the following statement(s) is/are true concerning options for surgical dressings? a. Hydrocolloids, such as karaya compounds, offer ... are highly useful in debriding necrotic and fibrous material from wounds and absorbing wound serum
Last Answer : Answer: a, d Although the simplest dressing of gauze and tape combined with the use of antibacterial ointment can achieve moist wound healing in most patients. A multitude of other ... agents have high absorbency for tissue wound fluid and debride necrotic and fibrous material from the wound
Description : A gene showing co-dominance has (a) alleles that are recessive to each other (b) both alleles independently expressed in the heterozygote (c) one allele dominant on the other (d) alleles tightly linked on the same chromosome.
Last Answer : (b) both alleles independently expressed in the heterozygote
Description : Tissues are constructed from many distinct cell types that perform different functions in response to signals from each other and the extracellular matrix. During tissue development and tissue regeneration, ... that stem cells undergo when they are required to generate a particular type of cell?
Last Answer : Asymmetric cell division. After asymmetric division, each of the two resulting daughter cells has a unique life course. For example, one daughter cell may differentiate into a specific cell type ( ... cell), whereas the other daughter cell may remain a stem cell with unlimited proliferative ability.
Description : The association of histone H1 with a nucleosome indicates that (a) DNA replication is occurring (b) the DNA is condensed into a chromatin fibre (c) the DNA double helix is exposed (d) transcription is occurring.
Last Answer : (b) the DNA is condensed into a chromatin fibre
Description : The association of histone H1 with a nucleosome indicates: (1) DNA replication is occurring. (2) The DNA is condensed into a Chromatin Fibre. (3) The DNA double helix is exposed. (4) Transcription is occurring.
Last Answer : (2) The DNA is condensed into a Chromatin Fibre.
Description : What are substances that are extended structures made up of billions of tightly packed atoms and molecules?
Description : What are the two main types of endocytosis ?
Last Answer : Endocytosis is the entrance of materia in the cell engulfed by portions of the cell membrane. Endocytosis can be classified as pinocytosis or phagocytosis. In pinocytosis small particles on ... receiving the name phagosome. Cell Membrane Review - Image Diversity: pynocitosis phagocytosis
Description : What are the three main types of passive transport ?
Last Answer : The three main types of passive transport are simple diffusion, osmosis and facilitated diffusion. Cell Membrane Review - Image Diversity: passive transport
Description : What types of signaling molecules bind to and activate RTKs?
Last Answer : Growth factors, hormones, some extracellular matrix proteins, some cell surface proteins (i.e. ephrin)
Description : What common cell types are regulated by ion channels and are commonly referred to as excitable cells?
Last Answer : neurons, muscle cells, sensory receptor cells
Description : Are all genes expressed at the same time in all cell types?
Last Answer : No- genes are expressed at different times or in different cells types. There are several sequences in DNA that regulate when a genes is transcribed, such as- promoters and enhancer ... to start transcription and operator sequences that allow for external proteins to cause activation or repression.
Description : Number of DNA coils over a nucleosome is
Last Answer : Number of DNA coils over a nucleosome is A. `23/4` B. `21/4` C. `13/4` D. `11/4`
Description : An octamer of 4 histones complexed with DNA forms (a) endosome (b) nucleosome (c) mesosome (d) centromere.
Last Answer : (b) nucleosome