Cytology

Normal, actively dividing cells of human red bone marrow are analyzed. What number of cells' chromosomes is typical for G1 period?

46

The Analysis ultrastructural constitution of the cells has shown it specialization to lipids and cholesterol synthesis. The development which organelles most typifying for such cells?

Agranular ER

Moving of the daughter chromatids to the poles of the cell is observed in the mitotically dividing cell. On what stage of the mitotic cycle is this cell?

Anaphase

Key differences between apoptotic and necrotic cell death include which of the following?

Apoptotic cells do not release factors that induce inflammation.

An 18-year-old student presents with enlarged thyroid gland accompanied by accelerated metabolism and increased heart rate. These signs can be observed during the hypersecretion of thyroxin. What organelles of thyroid cells are primarily responsible for hormone production and secretion?

Golgi apparatus

On the electronic photomicrograph of nervous cells of spinal ganglion, it was found organelles, with cisterns, flattened in the central part and extended on the periphery. Also, small vesicles were seen. How are these organelles called?

Golgi complex

The system of the limited by biomembrane cavities was researched in cells which function is defined by lipid and carbohydrate metabolism, detoxification and deposition of ion calcium. Name this organelle.

Granular ER

Cells of healthy liver actively synthesize glycogen and proteins. What organelles are the most developed in them?

Granular and agranular endoplasmic reticulum

As a result of activation of the ion channels of the external membrane, the rest potential of an excitable cell has greatly increased. What channels were activated?

K channels

Histological investigation of renal biopsy material taken from a patient with tuberculosis has revealed chaotically located chromatin granules in the focus of caseous necrosis. These changes are the result of:

Karyorrhexis

Students study the stages of gametogenesis. They analyze a cell with a haploid number of chromosomes, where each chromosome consisting of two chromatids. The chromosomes are located in the equatorial plane of the cell. Such a situation is typical of the following stage of meiosis:

Metaphase of the second division

Which one of the following substances is unable to traverse the plasma membrane by simple diffusion?

Na+

The life cycle of a cell includes the process of DNA autoreduplication. As a result of it monochromatid chromosomes turn into bichromatid ones. What period of the cell cycle does this phenomenon fall into?

S

RNA-polymerase B(II) is blocked due to amanitine poisoning (poison of death cup). It disturbs:

Synthesis of m-RNA

At a certain stage of the cell cycle chromosomes reach cellular poles, undergo despiralization; nuclear membranes are being formed around them; nucleolus is restored. What stage of mitosis is it?

Telophase

Which of the following best defines the term "exocytosis"?

The discharge of proteins in cytoplasmic vesicles from a cell following fusion of the vesicles with the plasmalemma

Ultramicroscopic study of the cell has shown well developed granular ER and Golgi apparatus. Indicate specialization of this cell.

The synthesis and secretion of proteins

Examination of a patient revealed reduced contents of magnesium ions that are necessary for attachment of ribosomes to the granular endoplasmic reticulum. It is known that it causes disturbance of protein biosynthesis. What stage of protein biosynthesis will be disturbed?

Translation

Binding of histone H1 proteins to importins is important for which of the following?

Transport through the nuclear pores complexes

A 56-year-old man has been taking atorvastatin because of a poor lipid profile and a family history of cardiovascular disease. The statin family of drugs enhances endocytosis of low-density lipoprotein (LDL) from the blood. Endocytosis of LDL differs from phagocytosis of bacterial cells in which of the following ways?

Use of clathrin-coated pits

One of the ways that cells communicate with each other is by secretion of various molecules. The secreted molecule is known as

a signalling molecule

Which one of the following transport processes require energy?

active transport

With a 5-year history of chronic respiratory infections, a 23-year old, non-smoking man is referred to an otolaryngologist. A bronchial biopsy indicates altered structures in the epithelial cells. Which of the following, if altered to reduce function, is most likely involved in this patient's condition?

cilia

What are the folds on the inner mitochondrial membrane called?

cristae

Transitions in the cell cycle from one phase to the next are regulated by protein kinases whose activity depends on what other proteins?

cyclins

Cholesterol functions in the plasmalemma to

decrease fluidity of the lipid bilayer

A 42-year-old woman of Mediterranean descent presents with multiple oral blisters and a few cutaneous blisters on her back and buttocks. The superficial bullae are fragile, some have unroofed to form ulcerated lesions, and there is a positive Nikolsky sign. Blood tests reveal antibodies to a subfamily of cadherins and immunohistochemical staining of a biopsy from the oral mucosa shows distribution of the antigen throughout the epithelium. In what structures is the defect that is causing this patient's condition?

desmosome

An electron micrograph shows a cell-to-cell adhesion consisting, in each cell, of an attachment plaque. The intercellular space is filled with an electron-dense substance including transmembrane fibrillar structures:

desmosome

The photomicrography shows joining the epithelial cells with basal membrane. Name this type of the epithelial attachment.

desmosome

Micromanipulator was used to extract one of the two centrioles of centrosome (cell center) from hepatocyte (liver cell). What process will STOP OCCURRING in this cell?

division

What is the term for the general process that cells us to bring things into the cell?

endocytosis

Golgi complex exports substances from a cell due to the fusion of the membrane saccule with the cell membrane. The saccule contents flow out. What process is it?

exocytosis

During research on amniotic fluid, gotten by amniocentesis (puncture of the amniotic cavity), it was discovered cells with sexual chromatin in their nuclei (Barr body). What can be said about this?

female sex of fetus

Using immunohistochemistry, a population of cells is shown to be positive for the protein connexin. From this we can infer that the cells are connected by what type of junction?

gap junction

What is also called a low resistance junction?

gap junction

Low level of albumins and fibrinogen was detected in the patient's blood. Decreased activity of what organelle of the liver hepatocytes can cause it?

granular endoplasmatic net

The prolonged influence of toxic substances on an organism resulted in considerable reduction of the synthesis of proteins in hepatocytes. What organelle did suffer from the intoxication more than others?

granular endoplasmic reticulum

In the life cycle of a cell during mitosis, a natural change in the amount of genetic material occurs. The DNA doubles at the following stage:

interphase

Electron microscopic study of a cell revealed roundish bubbles confined by a membrane and containing a lot of various hydrolytic enzymes. It is known that these organelles provide intracellular digestion and protective functions. These elements are:

lysosomes

In course of practical training students studied a stained blood smear of a mouse with bacteria phagocyted by leukocytes. What cell organelle completes digestion of these bacteria?

lysosomes

The cytochemical investigation revealed high content of hydrolytic enzymes in the cytoplasm. This phenomenon indicates the activity of the following organelles:

lysosomes

An individual genetically unable to synthesize normal occludin is likely to have epithelia with defective regulation in which of the following?

material crossing the epithelium between the cells (paracellular movement)

A specimen of an onion rootlet includes a cell in which the fully condensed chromosomes are located in the equatorial plane making the monaster. What phase of the mitotic cycle is the cell in?

metaphase

While studying maximally spiralized chromosomes of human karyotype the process of cell division was stopped in the following phase:

metaphase

Which of the following has a rigid wall composed of 13 protofilament strands?

microtubule

Which of the following is NOT a membranous organelle?

microtubules

Oval and round organelles with double wall are seen at the electron micrograph. The outer membrane is smooth, the inner membrane folded into cristae contain enzyme ATP synthase. These are:

mitochondria

Which of the following is an organelle?

mitochondria

The synthesis of histone proteins was artificially blocked in a cell. What structure of the cell will be damaged?

nuclear chromatin

Which of the following is a region of chromatin that is well developed in large neurons active in protein synthesis?

nucleolus

Analysis of an electron diffraction pattern of a cell revealed mitochondrion destruction. This might result in an abnormal course of the following cell process:

oxidation of organic substances

During histochemical research of hepatocyte in the cytoplasm of cell, it was found vesicles in diameter of 0.05-1.5µm filled with enzymes of peroxide oxidation - catalase, peroxidase. What is the name of organelle?

peroxisome

The electronic photomicrography shows the round vesicles by size 0,2 - 0,5 mcm covered by a membrane and filled by the matrix. The histochemical study of the matrix has found the enzyme catalase. Name it.

peroxisomes

Which organelle contains detoxifying enzymes?

peroxisomes

What is the limiting membrane of a cell?

plasmalemma

It was proved that a molecule of immature mRNA (precursor mRNA) contained more triplets than amino acids found in the synthesized protein. The reason for that is that translation is normally preceded by:

processing

Mitotic figures visible in a tissue section from the lining of the small intestine are most likely to belong to which of the following categories?

progenitor cells

Formation of ribosome subunits in a cell was disturbed in course of an experiment (by means of activated mutagenic factors). This will have an effect on the following metabolic process:

protein biosynthesis

Glycocalix of cell plasmolemma is damaged as a result of microbe toxins action. Which membrane function of the cells is broken in the first place?

receptor

A 50-year-old woman had her tooth extracted. The tissue regenerated. Which of the following organella are the most active during tissue regeneration?

ribosomes

A tissue sample of a benign tumor was studied under the electron microscope. A lot of small (15-20 nm) spherical bodies, consisting of 2 unequal subunits were detected. These are:

ribosomes

Labeled amino acids alanine and tryptophan were injected to a mouse in order to study the localization of protein synthesis in its cells. The labeled amino acids will be accumulated near the following organelles:

ribosomes

The electronic photomicrography shows the round structure by size 15-20 nm consisting of big and small subunits. It is known that this organelle provides protein synthesis. Indicate it.

ribosomes

Which organelle produces protein for export?

rough endoplasmic reticulum

Which organelle is involved in lipid metabolism?

smooth endoplasmic reticulum

Examination of the blood smear of a young patient reveals misshapen red blood cells, and the pathology report indicates hereditary spherocytosis. Defects in which one of the following proteins cause this condition?

spectrin

Ultramicroscopic examination of "dark" hepatocyte population in the cell cytoplasm detected a developed granular endoplasmic reticulum. What function has this organelle in these cells?

synthesis of blood plasma protein

A patient has decreased concentration of magnesium ions that are required for ribosomes connection to the granular endoplasmic reticulum. This condition is known to disturb the process of protein biosynthesis. A disturbance occurs at the following stage:

translation

An animal had been intensively fed with carbohydrates. Histological examination of its liver revealed a significant number of glycogen granules. Glycogen relates to the following group of cell structures:

trophic granules

Symport refers to the process of transporting

two different molecules in the same direction