1.
In a cycle, interphase include
Correct Answer
B. G1, S and G2
Explanation
The correct answer is G1, S and G2. Interphase is the longest phase of the cell cycle and it is when the cell prepares for cell division. During interphase, the cell grows, replicates its DNA in the S phase, and prepares for division in the G2 phase. G1 phase is the period of growth and preparation before DNA replication. Therefore, the correct answer includes G1, S, and G2 as they are all part of interphase.
2.
Which one of the following is the best description of mitosis? Is is
Correct Answer
B. A type of cell division resulting in two new cells each one just ike the original cell in chromosome number and kind
Explanation
Mitosis is a type of cell division that results in two new cells, each one being identical to the original cell in terms of chromosome number and kind. During mitosis, the cell's DNA is replicated, and the replicated chromosomes are divided equally between the two new cells. This process allows for growth, repair, and replacement of cells in multicellular organisms. It is not related to a cell exiting the cell cycle into G0, the replication of DNA, or referring to the G1 activity of a cell.
3.
A cleavage furrow forms during
Correct Answer
C. TelopHase
Explanation
During telophase, the final stage of mitosis, the nuclear envelope reforms around the separated chromosomes, and the chromosomes begin to decondense. At the same time, a cleavage furrow starts to form in animal cells. The cleavage furrow is a contractile ring made of actin and myosin filaments that begins to constrict, eventually leading to the division of the cytoplasm and the formation of two daughter cells. This process is known as cytokinesis and occurs during telophase. Therefore, the correct answer is telophase.
4.
Which one of the following best descibes prophase?
Correct Answer
A. The nuclear membrane dissipates and the spindle forms
Explanation
During prophase, the nuclear membrane breaks down, allowing the genetic material (chromosomes) to be exposed in the cytoplasm. At the same time, the spindle apparatus, composed of microtubules, starts to form. This spindle apparatus helps in the movement and separation of the chromosomes during cell division. Therefore, the correct answer is "The nuclear membrane dissipates and the spindle forms."
5.
At the end of mitosis each new cell as
Correct Answer
D. 46 chromosomes
Explanation
At the end of mitosis, each new cell has 46 chromosomes. This is because during mitosis, the cell undergoes a process called chromosome duplication, where each chromosome is replicated to form two identical sister chromatids. The sister chromatids are held together by a centromere. When the cell divides, each daughter cell receives one set of chromosomes, resulting in 46 chromosomes in each new cell.
6.
The first step in DNA replication is
Correct Answer
B. The bonds between the nitrogen bases "break" and the DNA opens
Explanation
In the first step of DNA replication, the bonds between the nitrogen bases break and the DNA molecule opens up. This allows the DNA to separate into two strands, creating a replication fork. This separation of the DNA strands is necessary for the replication process to occur, as it allows the enzymes involved to access the individual strands and begin the synthesis of new complementary strands using the existing strands as templates.
7.
DNA replication occurs during
Correct Answer
A. The S segment
Explanation
DNA replication occurs during the S segment of the cell cycle. The S segment, also known as the synthesis phase, is the phase in which DNA replication takes place. During this phase, the cell synthesizes a copy of its DNA in preparation for cell division. The replication process ensures that each daughter cell receives an identical copy of the genetic material. This is a crucial step in cell division and the transmission of genetic information to subsequent generations of cells.
8.
When DNA replication is over there will be two chromatids formed, each one composed of half "old" DNA and half "new" nucleotides
Correct Answer
A. True
Explanation
After DNA replication, each chromosome is composed of two identical chromatids, which are held together by a centromere. Each chromatid is made up of half "old" DNA (from the original strand) and half "new" nucleotides (synthesized during replication). This process ensures the accurate transmission of genetic information to the daughter cells during cell division. Therefore, the statement is true.
9.
In protein synthesis, messenger RNA is produced during a process called
Correct Answer
B. Transcription
Explanation
In protein synthesis, messenger RNA (mRNA) is produced during a process called transcription. Transcription is the process by which the DNA sequence in a gene is copied into mRNA. This process occurs in the nucleus of the cell and involves the enzyme RNA polymerase. The mRNA molecule then carries the genetic information from the DNA to the ribosomes in the cytoplasm, where it serves as a template for protein synthesis during translation. Therefore, transcription is the correct answer as it accurately describes the production of mRNA in protein synthesis.
10.
The energy for the attachment of nucleotides during DNA replication comes from
Correct Answer
B. The high energy pHospHates that are a part of the nucleotides
Explanation
During DNA replication, nucleotides are added to the growing DNA strand. This process requires energy. The high energy phosphates that are a part of the nucleotides provide this energy. When the nucleotide is added to the growing strand, the high energy phosphate group is hydrolyzed, releasing energy that is used to form the phosphodiester bond between the nucleotides. This energy release allows the DNA replication process to proceed efficiently and accurately.
11.
In protien synthesis, if the mRNA code reads GAU, the tRNA would read
Correct Answer
B. CUA
Explanation
The mRNA code GAU corresponds to the amino acid aspartic acid. According to the genetic code, the tRNA anticodon that pairs with GAU is CUA. The tRNA molecule carries the specific amino acid to the ribosome during protein synthesis. Therefore, the correct answer is CUA.
12.
The pattern for the production of mRNA is
Correct Answer
B. DNA
Explanation
The correct answer is DNA because mRNA is synthesized through a process called transcription, where the DNA sequence is used as a template to produce a complementary RNA molecule. This RNA molecule is then processed and modified to form mature mRNA, which carries the genetic information from DNA to the ribosomes for protein synthesis. Therefore, DNA is the correct answer as it is the initial template for mRNA production.
13.
The job of tRNA is to transfer
Correct Answer
B. Amino acids from the cytoplasm to the ribosome
Explanation
tRNA, or transfer RNA, is responsible for transferring amino acids from the cytoplasm to the ribosome during protein synthesis. It does not transfer a code from DNA to mRNA, as that is the role of RNA polymerase. It also does not transfer hydrogen to water or mRNA from the nucleus to the ribosome. Therefore, the correct answer is that tRNA transfers amino acids from the cytoplasm to the ribosome.
14.
The metabolic activity of cellular respiration is actually
Correct Answer
D. A series of exothermic reactions
Explanation
Cellular respiration is the process by which cells convert glucose and oxygen into carbon dioxide, water, and energy in the form of ATP. This process involves several steps, including glycolysis, the Krebs cycle, and oxidative phosphorylation, all of which release energy in the form of heat. Since the reactions in cellular respiration release energy, they are classified as exothermic reactions. Therefore, the correct answer is "a series of exothermic reactions."
15.
Glucose is trapped in bod cells by
Correct Answer
D. pHspHorylation
Explanation
Phosphorylation is the process by which a phosphate group is added to a molecule. In the case of glucose, phosphorylation occurs when a phosphate group is added to glucose to form glucose-6-phosphate. This phosphorylation reaction traps glucose inside the cell, as the charged phosphate group prevents glucose from easily diffusing out of the cell. Therefore, phosphorylation is the mechanism by which glucose is trapped inside body cells.
16.
Glycolysis begins when an enzyme converts glucose to two
Correct Answer
B. Pyruvic acid molecules
Explanation
Glycolysis is the metabolic pathway that breaks down glucose into pyruvate molecules. During this process, an enzyme called pyruvate kinase converts glucose into two molecules of pyruvic acid. Therefore, the correct answer is pyruvic acid molecules.
17.
The kreb's cycle occurs
Correct Answer
C. In the matrix of mitochondria
Explanation
The Kreb's cycle, also known as the citric acid cycle, is a series of biochemical reactions that occur in the matrix of mitochondria. The matrix is the innermost compartment of the mitochondria, where several metabolic processes take place. This is where the Kreb's cycle occurs, leading to the production of energy-rich molecules such as ATP. The other options mentioned, such as the cristae, cytoplasm, and ribosomes, are not involved in the Kreb's cycle.
18.
The two Carbon compound that enters the Kreb's cycle is
Correct Answer
B. The acetyl group
Explanation
The Kreb's cycle is a series of chemical reactions that occur in the mitochondria of cells, and it is an important part of cellular respiration. During the Kreb's cycle, two carbon compounds enter the cycle in the form of the acetyl group. The acetyl group is derived from the breakdown of glucose or pyruvic acid, which are both products of glycolysis. Once the acetyl group enters the Kreb's cycle, it undergoes a series of reactions, producing energy-rich molecules such as ATP and NADH. Therefore, the acetyl group is the correct answer as it is the actual compound that enters the Kreb's cycle.
19.
In on turn of a Kreb's cycle how many CO2's are released?
Correct Answer
C. 2
Explanation
In one turn of the Kreb's cycle, two molecules of carbon dioxide (CO2) are released. This occurs during the conversion of isocitrate to alpha-ketoglutarate and during the conversion of alpha-ketoglutarate to succinyl-CoA. These reactions involve the decarboxylation of isocitrate and alpha-ketoglutarate, resulting in the release of two CO2 molecules. Therefore, the correct answer is 2.
20.
When the catabolism of one glucose molecule is finished, how many total CO2 molecules have been released?
Correct Answer
C. 6
Explanation
During the catabolism of one glucose molecule, it goes through several metabolic pathways such as glycolysis, the citric acid cycle, and oxidative phosphorylation. In these pathways, glucose is broken down into smaller molecules, and carbon dioxide (CO2) is released as a byproduct. In glycolysis, one glucose molecule is converted into two molecules of pyruvate, but no CO2 is released. However, during the citric acid cycle, each pyruvate molecule is further broken down, and one CO2 molecule is released. Since there are two pyruvate molecules produced from one glucose molecule, a total of two CO2 molecules are released in the citric acid cycle. Therefore, when the catabolism of one glucose molecule is finished, a total of six CO2 molecules have been released.
21.
The hydrogen transfer system occurs where?
Correct Answer
A. On the cristae of the mitochondria
Explanation
The hydrogen transfer system occurs on the cristae of the mitochondria. The cristae are the folded inner membranes of the mitochondria, which provide a large surface area for various metabolic reactions to take place. The hydrogen transfer system refers to the process of transferring hydrogen ions (protons) across the cristae membrane during cellular respiration. This transfer is essential for generating ATP, the energy currency of the cell. Therefore, the hydrogen transfer system occurs on the cristae of the mitochondria.
22.
Under normal conditions, at the end of the hydrogen transfer system, the final hydrogen acceptor is
Correct Answer
D. 1/2 O2
Explanation
Under normal conditions, the final hydrogen acceptor at the end of the hydrogen transfer system is 1/2 O2. This means that oxygen is the molecule that accepts the hydrogen atoms. In biological processes such as cellular respiration, oxygen acts as the final electron acceptor in the electron transport chain. It accepts the electrons and protons from the hydrogen atoms, forming water (H2O) as a byproduct. Therefore, 1/2 O2 is the correct answer as it represents the role of oxygen as the final hydrogen acceptor.
23.
How many ATPs are generated by one hydrogen moving along the entire hydrogen transfer system?
Correct Answer
C. 3
Explanation
One hydrogen moving along the entire hydrogen transfer system generates 3 ATPs. This is because during oxidative phosphorylation, each NADH molecule that enters the electron transport chain can generate 3 ATPs, while each FADH2 molecule can generate 2 ATPs. Since one hydrogen molecule is equivalent to one NADH molecule, it can generate 3 ATPs.
24.
Which one of the following does not belong in the list?
Correct Answer
B. Pyruvic acid
Explanation
The given list consists of organic acids commonly found in biological systems. Citric acid, oxaloacetic acid, and succinic acid are all intermediates in the citric acid cycle, which is a central metabolic pathway in cells. Pyruvic acid, on the other hand, is not directly involved in the citric acid cycle. It is a product of glycolysis, the initial step in cellular respiration. Therefore, pyruvic acid does not belong in the list of acids associated with the citric acid cycle.
25.
The four major groups of tissues are
Correct Answer
C. Epithelium, connective, muscle and nerve
Explanation
The correct answer is epithelium, connective, muscle, and nerve. These four groups of tissues represent the main types of tissues found in the human body. Epithelium tissue covers and protects the body's surfaces and organs. Connective tissue provides support and connects different structures in the body. Muscle tissue allows for movement and is responsible for contraction. Nerve tissue transmits electrical signals and allows for communication within the body.
26.
Epethelial tissues are vascular
Correct Answer
A. True
Explanation
Epithelial tissues are avascular, meaning they do not have blood vessels. They obtain nutrients and oxygen through diffusion from nearby blood vessels in the underlying connective tissue. This is because epithelial tissues are composed of tightly packed cells that form a protective barrier and allow for selective permeability. The lack of blood vessels also helps in preventing excessive bleeding in case of injury to the epithelial tissue. Therefore, the correct answer is true.
27.
Simple squamous tissue
Correct Answer
D. All of these
Explanation
Simple squamous tissue is a type of epithelial tissue that consists of a single layer of flat cells. It is well-suited for diffusion and filtration processes due to its thin structure. The tissue covers the cornea, which is the transparent outer layer of the eye. It also lines the alveoli of the lungs, where gas exchange occurs, and lines the blood vessels, allowing for the exchange of substances between the blood and surrounding tissues. Therefore, the correct answer is "all of these" as simple squamous tissue is found in all of these locations.
28.
A location of nonkeratinized stratified squamous epithelium is
Correct Answer
A. Covers lips
Explanation
The correct answer is "covers lips." Nonkeratinized stratified squamous epithelium refers to a type of tissue that is found in areas of the body that need protection but also need to remain moist, such as the lining of the lips. This type of epithelium does not have a layer of dead cells, known as keratin, on its surface, which allows it to stay moist and flexible. Therefore, it is the most suitable tissue to cover the lips, which are constantly exposed to moisture and movement.
29.
Bladders are lined with
Correct Answer
B. Transistional epithelium
Explanation
Transitional epithelium is the correct answer because it is a specialized type of epithelial tissue that lines the urinary bladder. It is capable of stretching and contracting, allowing the bladder to expand and accommodate urine without rupturing. This type of epithelium is also found in other organs of the urinary system, such as the ureters and urethra, where its unique properties are necessary for their function.
30.
Which one of the following may have goblet cells and/or microvilli
Correct Answer
B. Columnar
Explanation
Columnar epithelial cells are specialized cells that line the digestive tract and respiratory tract. They are characterized by the presence of goblet cells, which secrete mucus, and microvilli, which increase the surface area for absorption and secretion. This type of epithelium is found in regions where secretion and absorption are important functions, such as the stomach, intestines, and bronchi. Therefore, columnar epithelial cells are the most likely to have both goblet cells and microvilli.
31.
The visceral layer of a serous membrane
Correct Answer
B. Covers the organs in a cavity
Explanation
The visceral layer of a serous membrane covers the organs in a cavity. This layer is responsible for protecting and lubricating the organs, reducing friction between them and the surrounding structures. It is a vital component of the serous membrane, which consists of two layers - the visceral layer and the parietal layer. The visceral layer specifically covers the organs, while the parietal layer lines the cavity containing the organ. Therefore, the correct answer is "covers the organs in a cavity".
32.
Which one of the following is not a part of the matrix connective tissues?
Correct Answer
B. Canaliculi
Explanation
Canaliculi is not a part of the matrix connective tissues. Canaliculi refers to the small channels or canals that connect the lacunae (small spaces) within bone tissue, allowing for the exchange of nutrients and waste products between osteocytes (bone cells). While collagen, calcium, and water are all components of the matrix connective tissues, canaliculi is not directly a part of the matrix but rather a feature of bone tissue.
33.
Which one of these "holds your skin on"?
Correct Answer
D. Areolar
Explanation
Areolar tissue is a type of connective tissue that holds the skin to the underlying structures. It forms a loose, mesh-like network of fibers that provides support and elasticity to the skin. Adipose tissue is responsible for storing fat, dermis is the middle layer of the skin, and skeletal muscle is responsible for movement. Therefore, areolar tissue is the correct answer as it specifically functions to hold the skin in place.
34.
Which one of the following best descrbles the matrix of the tissue that forms ligaments and tendons?
Correct Answer
A. A dense compact collagenous fibers
Explanation
The correct answer is "a dense compact collagenous fibers." This option best describes the matrix of the tissue that forms ligaments and tendons. Collagen is the main component of ligaments and tendons, providing strength and flexibility. The term "dense" indicates a high concentration of collagen fibers, while "compact" suggests a tightly packed arrangement. This aligns with the structural characteristics of ligaments and tendons, which require a dense and organized collagen matrix to withstand tension and transmit forces.
35.
Which one of the following contains blood vessels and nerves?
Correct Answer
D. Perichondrium
Explanation
Perichondrium is the correct answer because it is a dense connective tissue layer that surrounds cartilage. It contains blood vessels, which supply oxygen and nutrients to the cartilage cells, and nerves, which provide sensory innervation. Canaliculi are small channels in bone that allow for the exchange of nutrients and waste between osteocytes, lacunae are small spaces in bone where osteocytes are located, and fat vacuole is a storage site for fat cells.
36.
A location of hyaline cartilage is
Correct Answer
B. Ends of long bones
Explanation
Hyaline cartilage is a type of flexible connective tissue that provides support and reduces friction between bones. It is found at the ends of long bones, such as the femur and humerus, where it forms the articular cartilage. This cartilage allows smooth movement of the joints and helps absorb shock during activities like walking or running. The other options mentioned, such as the pinna of the ear, eustachian tube, and intervertebral discs, are not primarily composed of hyaline cartilage.
37.
Which one of the following does not belong in the list?
Correct Answer
C. Fibroblasts
Explanation
The given list consists of terms related to bone structure. Osteon, canaliculi, and lamellae are all components of bone tissue, specifically the microscopic structure of compact bone. Fibroblasts, on the other hand, are cells found in connective tissue and are not directly associated with bone structure. Therefore, fibroblasts do not belong in the list.
38.
Haversian canals contain
Correct Answer
C. Blood vessels
Explanation
Haversian canals are microscopic channels found in compact bone. These canals contain blood vessels, which transport oxygen, nutrients, and waste products to and from the bone cells. The blood vessels play a crucial role in maintaining the health and function of the bone tissue. The other options, such as lacunae (small spaces where bone cells reside), osteocytes (mature bone cells), and canaliculi (tiny channels that connect lacunae), are also present in the Haversian system, but the primary component found within the Haversian canals is blood vessels.
39.
Which one of the following connects osteocytes to their blood supply?
Correct Answer
B. Canaliculi
Explanation
Canaliculi are small channels that connect osteocytes, which are bone cells, to their blood supply. These channels allow for the exchange of nutrients and waste products between the osteocytes and the blood vessels. Lacunae are small spaces within the bone where the osteocytes are located. Haversian canals are larger channels that contain blood vessels and nerves. Osteons are the structural units of compact bone, consisting of concentric layers of bone tissue surrounding a central canal.
40.
Reticular tissue is found in
Correct Answer
D. All of these
Explanation
Reticular tissue is a type of connective tissue that is characterized by its network of reticular fibers. It provides structural support to various organs and tissues. Lymph nodes, spleen, and tonsils are all lymphoid organs that play a crucial role in the immune system. They contain reticular tissue, which forms the framework for the cells and tissues involved in immune responses. Therefore, the correct answer is "all of these."
41.
The matrix of blood is the
Correct Answer
A. Plasma
Explanation
The matrix of blood refers to the fluid component of blood, which is called plasma. Plasma makes up about 55% of the total volume of blood and contains various substances such as water, proteins, hormones, electrolytes, and waste products. It is responsible for transporting nutrients, hormones, and waste materials throughout the body, maintaining blood pressure, and regulating body temperature. Red blood cells, white blood cells, and clotting cells are cellular components found within the plasma, but they do not make up the matrix of blood.
42.
In skeletal muscle tissue, the surface membrane of each fiber is called the
Correct Answer
A. Sarcolemme
Explanation
The surface membrane of each muscle fiber in skeletal muscle tissue is called the sarcolemma. The sarcolemma is responsible for maintaining the integrity of the muscle fiber and controlling the movement of substances in and out of the cell. It also plays a role in transmitting electrical impulses, known as action potentials, along the muscle fiber, which ultimately leads to muscle contraction. The sarcolemma is essential for the proper functioning of skeletal muscle tissue.
43.
Visceral muslce is located in the
Correct Answer
C. Walls of internal organs except the heart
Explanation
Visceral muscle, also known as smooth muscle, is found in the walls of internal organs except the heart. This type of muscle is involuntary and is responsible for the movement and contraction of various organs such as the stomach, intestines, bladder, and blood vessels. Unlike skeletal muscle, which is attached to bones and responsible for voluntary movements, visceral muscle works automatically to control the functions of internal organs. Therefore, the correct answer is "walls of internal organs except the heart."
44.
Neuroglial cells
Correct Answer
D. All of these
Explanation
Neuroglial cells are a type of cells that support and protect neurons. They do not conduct impulses themselves, but they play a crucial role in maintaining the function and health of neurons. Neuroglial cells are found not only in nerve tissue but also in other parts of the nervous system, such as the brain and spinal cord. Therefore, the correct answer is "all of these" because neuroglial cells support and protect neurons, do not conduct impulses, and are found in nerve tissue.
45.
The epidermis of the skin is composed of
Correct Answer
D. Stratified squamous epithelium
Explanation
The epidermis is the outermost layer of the skin and is responsible for protecting the underlying tissues. It is composed of stratified squamous epithelium, which means that it is made up of multiple layers of flattened cells. This type of epithelium is well-suited for providing a barrier against mechanical stress, dehydration, and microbial invasion. It also helps in preventing the loss of water from the body and regulates temperature. Therefore, the correct answer is stratified squamous epithelium.
46.
The five layers of the epidermis are the stratum
1.lucidum 2. corneum 3.granulosum 4.spinosum 5. basale
Correct Answer
B. 5,4,3,2,1
Explanation
The correct answer is 5,4,3,2,1. The epidermis is composed of five layers, starting from the deepest layer to the most superficial layer. The deepest layer is the stratum basale, followed by the stratum spinosum, stratum granulosum, stratum corneum, and finally the stratum lucidum. This order represents the progression of cells from the actively dividing layer to the layer of dead cells that protect the body.
47.
Keratin and melanin begin to be produced in the stratum
Correct Answer
B. Basale
Explanation
Keratin and melanin begin to be produced in the stratum basale. This is the deepest layer of the epidermis and contains cells that are actively dividing. Keratin is a protein that provides strength and protection to the skin, hair, and nails, while melanin is a pigment responsible for the color of the skin, hair, and eyes. The stratum basale is where these important substances are first synthesized and then gradually move up to the outer layers of the epidermis.
48.
Which on of the following is composed of dead, keratinized cells?
Correct Answer
C. Stratum corneum
Explanation
The stratum corneum is composed of dead, keratinized cells. Keratinization is the process by which cells in the outermost layer of the epidermis become filled with keratin, a tough protein. These cells lose their nucleus and other organelles, and become flattened and tightly packed together. The stratum corneum acts as a protective barrier for the underlying layers of the skin, preventing dehydration and protecting against external factors such as pathogens and UV radiation.