IB Biology Practice Test Quiz

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IB Biology Practice Test Quiz - Quiz

You might be just starting in your studies on biology, or you might be gearing up for your finals, but either way, you can never be too prepared for a test on the scientific study of life! The topic looks at a broad range of life’s aspects from human reproduction to the physical makeup of our bodies and the other organisms in the world. What can you tell us about biology? Let’s find out.


Questions and Answers
  • 1. 

    The lengths of a sample of tiger canines were measured. 68 % of the lengths fell within a range between 15 mm and 45 mm. The mean was 30 mm. What is the standard deviation of this sample?

    • A.

      5 mm

    • B.

      15 mm

    • C.

      7.5 mm

    • D.

      30 mm

    Correct Answer
    B. 15 mm
    Explanation
    The standard deviation measures the amount of variation or dispersion in a set of data. In this case, we know that 68% of the lengths fell within a range between 15 mm and 45 mm, and the mean is 30 mm. This means that the data is fairly spread out around the mean. Since the range is 30 mm (45 mm - 15 mm), and the data is evenly distributed within this range, we can assume that the standard deviation is half of the range, which is 15 mm. Therefore, the standard deviation of this sample is 15 mm.

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  • 2. 

    Which of the following are features of prokaryotes and eukaryotes? 70S ribosomes 80S ribosomes Naked DNA DNA associated with proteins 70S ribosomes         80S ribosomes           Naked DNA           DNA associatedwith proteins

    • A.

      Prokaryote          eukaryote            prokaryote                eukaryote

    • B.

      Eukaryote           prokaryote           eukaryote                 prokaryote

    • C.

      Eukaryote          prokaryote           prokaryote                    eukaryote

    • D.

      Prokaryote       eukaryote          eukaryote                        prokaryote

    Correct Answer
    A. Prokaryote          eukaryote            prokaryote                eukaryote
    Explanation
    Both prokaryotes and eukaryotes have ribosomes, but they differ in size. Prokaryotes have 70S ribosomes, while eukaryotes have 80S ribosomes. Additionally, both types of cells have DNA, but it is organized differently. Prokaryotes have naked DNA, meaning it is not associated with proteins, while eukaryotes have DNA that is associated with proteins. Therefore, the correct answer is prokaryote-eukaryote-prokaryote-eukaryote.

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  • 3. 

    Which statement is part of the cell theory? .

    • A.

      Cells are composed of organic molecules.

    • B.

      Cells have DNA as their genetic material

    • C.

      Cells have cytoplasm surrounded by a membrane.

    • D.

      Cells come from pre-existing cells.

    Correct Answer
    D. Cells come from pre-existing cells.
    Explanation
    The statement "Cells come from pre-existing cells" is part of the cell theory. This theory states that all living organisms are composed of cells, cells are the basic unit of structure and function in living organisms, and cells can only arise from pre-existing cells through cell division. This statement supports the idea that new cells are formed through the division of existing cells, rather than spontaneously appearing.

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  • 4. 

    What route is used to export proteins from the cell?

    • A.

      Golgi apparatus → rough endoplasmic reticulum → plasma membrane

    • B.

      Rough endoplasmic reticulum → Golgi apparatus → plasma membrane

    • C.

      Golgi apparatus → lysosome → rough endoplasmic reticulum

    • D.

      Rough endoplasmic reticulum → lysosome → Golgi apparatus

    Correct Answer
    B. Rough endoplasmic reticulum → Golgi apparatus → plasma membrane
    Explanation
    Proteins are synthesized on ribosomes attached to the rough endoplasmic reticulum (ER). After synthesis, the proteins are transported from the rough ER to the Golgi apparatus for further processing and modification. The Golgi apparatus then packages the proteins into vesicles and transports them to the plasma membrane for export out of the cell. Therefore, the correct route for exporting proteins from the cell is rough endoplasmic reticulum → Golgi apparatus → plasma membrane.

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  • 5. 

    Which of the following take(s) place during either interphase or mitosis in animal cells? I. Re-formation of nuclear membranes II. Pairing of homologous chromosomes III. DNA replication

    • A.

      I only

    • B.

      I and II only

    • C.

      II and III only

    • D.

      I and III only

    Correct Answer
    D. I and III only
    Explanation
    During interphase, which is the longest phase of the cell cycle, DNA replication occurs. This is the process in which the DNA molecule is duplicated to prepare for cell division. The re-formation of nuclear membranes occurs during the telophase stage of mitosis, which is the final stage of cell division. Therefore, the correct answer is I and III only.

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  • 6. 

    Which substance in prokaryotes contains sulfur?

    • A.

      DNA

    • B.

      Phospholipids

    • C.

      Proteins

    • D.

      Antibiotics

    Correct Answer
    C. Proteins
    Explanation
    Proteins in prokaryotes contain sulfur. Sulfur is an essential element in the structure of certain amino acids, such as cysteine and methionine, which are building blocks of proteins. These sulfur-containing amino acids play important roles in protein folding, enzyme activity, and protein-protein interactions. Therefore, proteins are the substance in prokaryotes that contain sulfur.

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  • 7. 

    Which describes these molecules correctly?       I                                                          II

    • A.

      Ribose                                           aminoacid

    • B.

      Glucose                                           aminoacid

    • C.

      Ribose                                                  fatty acid

    • D.

      Glucose                                                fatty acid

    Correct Answer
    D. Glucose                                                fatty acid
    Explanation
    The correct answer is glucose fatty acid. This is because glucose is a type of sugar molecule and fatty acid is a type of lipid molecule. These two molecules have different structures and functions in the body. Amino acids are the building blocks of proteins, so the combinations of ribose or glucose with amino acids would not be accurate descriptions.

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  • 8. 

    What sequence of processes is carried out by the structure labelled X during translation?

    • A.

      Combining with an amino acid and then binding to an anticodon

    • B.

      Binding to an anticodon and then combining with an amino acid

    • C.

      Binding to a codon and then combining with an amino acid

    • D.

      Combining with an amino acid and then binding to a codon

    Correct Answer
    D. Combining with an amino acid and then binding to a codon
    Explanation
    The structure labelled X in translation first combines with an amino acid, forming an aminoacyl-tRNA complex. This complex then binds to a codon on the mRNA molecule through its anticodon, allowing for the correct amino acid to be added to the growing polypeptide chain.

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  • 9. 

    The diagram below shows a biochemical pathway in a yeast cell. Which of the following correctly identifies a compound in te diagram?

    • A.

      I is fat.

    • B.

      II is pyruvate

    • C.

      III is lactate.

    • D.

      IV is carbon dioxide.

    Correct Answer
    B. II is pyruvate
    Explanation
    The diagram represents a biochemical pathway in a yeast cell. Compound II in the diagram is correctly identified as pyruvate. This is because pyruvate is a key intermediate molecule in the process of glycolysis, which is shown in the diagram. Pyruvate is produced from glucose and serves as a precursor for various metabolic pathways, including fermentation or conversion to acetyl-CoA for entry into the citric acid cycle. Therefore, based on the pathway and the role of compound II, it can be concluded that II is pyruvate.

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  • 10. 

    Which of the following factors influence(s) the rate of oxygen production in photosynthesis? I. Temperature II. Wavelength of light III. Number of mitochondria

    • A.

      I only

    • B.

      I and II only

    • C.

      II and III only

    • D.

      I, II and III

    Correct Answer
    B. I and II only
    Explanation
    The rate of oxygen production in photosynthesis is influenced by temperature and the wavelength of light. Temperature affects the activity of enzymes involved in the photosynthetic process, and different wavelengths of light are absorbed by different pigments in the chloroplasts, which affects the rate of photosynthesis. The number of mitochondria, on the other hand, is not directly related to the rate of oxygen production in photosynthesis.

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  • 11. 

    In some people, hemoglobin always contains the amino acid valine in place of a glutamic acid at one position in the protein. What is the cause of this?

    • A.

      An error in transcription of the hemoglobin gene

    • B.

      An error in translation of the mRNA

    • C.

      Lack of glutamic acid in the diet

    • D.

      A base substitution in the hemoglobin gene

    Correct Answer
    D. A base substitution in the hemoglobin gene
    Explanation
    A base substitution in the hemoglobin gene is the cause of the amino acid valine replacing glutamic acid in some people's hemoglobin. This means that during the replication of the DNA, there was a change in one of the bases, resulting in a different amino acid being coded for. This change in the genetic code leads to the incorporation of valine instead of glutamic acid in the hemoglobin protein.

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  • 12. 

    What is a suspected heterozygous individual crossed with in a test cross?

    • A.

      Homozygous dominant

    • B.

      Homozygous recessive

    • C.

      Heterozygous dominant

    • D.

      Heterozygous recessive

    Correct Answer
    B. Homozygous recessive
    Explanation
    In a test cross, a suspected heterozygous individual is crossed with a homozygous recessive individual. This is done to determine the genotype of the suspected heterozygote. If the offspring show the dominant phenotype, it means that the suspected individual is heterozygous. However, if the offspring show the recessive phenotype, it indicates that the suspected individual is homozygous dominant. By crossing with a homozygous recessive individual, the recessive allele can be revealed if it is present in the suspected heterozygote.

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  • 13. 

    Which of the following genotypes is possible in the offspring of a homozygous male with blood group A and a female with blood group?

    Correct Answer
    B.
  • 14. 

    What type of inheritance is shown in this pedigree chart?

    • A.

      X-linked dominant

    • B.

      Y-linked dominant

    • C.

      X-linked recessive

    • D.

      Y-linked recessive

    Correct Answer
    C. X-linked recessive
    Explanation
    This pedigree chart shows X-linked recessive inheritance. This means that the trait being observed is located on the X chromosome, and it is recessive, meaning that individuals need to inherit two copies of the trait to express it. Since the trait is recessive, it is more commonly observed in males who only have one X chromosome. Females, on the other hand, need to inherit the trait from both parents to express it. This pattern of inheritance is consistent with X-linked recessive inheritance.

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  • 15. 

    What is a community?

    • A.

      . A group of organisms living and interacting in the same trophic level

    • B.

      A group of populations living and interacting in a food chain

    • C.

      A group of organisms of the same species living and interacting in an ecosystem

    • D.

      A group of populations living and interacting in an area

    Correct Answer
    D. A group of populations living and interacting in an area
    Explanation
    A community refers to a group of populations of different species that live in the same area and interact with each other. This interaction can involve various types of relationships such as competition, predation, and mutualism. The populations within a community are interconnected and depend on each other for resources and survival.

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  • 16. 

    What are the units of a pyramid of energy?

    Correct Answer
    A.
    Explanation
    A pyramid of energy represents the flow of energy through different trophic levels in an ecosystem. It shows the amount of energy transferred from one trophic level to the next. The units of a pyramid of energy are typically represented in kilocalories (kcal) or joules (J) per unit area per unit time, such as kcal/m²/year or J/m²/year. This unit indicates the amount of energy that is available to the organisms at each trophic level and demonstrates the decrease in energy as it moves up the food chain.

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  • 17. 

    Population size is influenced by certain factors.If I = immigration, E = emigration, N = natality, M = mortality and (N + M) = (I + E) = 0, which phase is this population in?

    • A.

      Exponential phase

    • B.

      Transitional phase

    • C.

      Plateau phase

    • D.

      Growth phase

    Correct Answer
    C. Plateau pHase
    Explanation
    If (N + M) = (I + E) = 0, it means that the number of individuals being born (natality) and dying (mortality) is equal to the number of individuals immigrating and emigrating. This indicates that the population is not experiencing any net growth or decline. In the plateau phase, the population size remains relatively stable over time. Therefore, the correct answer is Plateau phase.

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  • 18. 

    An animal has radial symmetry, a sac-like body with only one opening and tentacles with stinging structures. To which phylum does this animal belong?

    • A.

      Annelida

    • B.

      Cnidaria

    • C.

      Mollusca

    • D.

      Porifera

    Correct Answer
    B. Cnidaria
    Explanation
    The characteristics described in the question, such as radial symmetry, a sac-like body with only one opening, and tentacles with stinging structures, are all typical of animals belonging to the phylum Cnidaria. Cnidarians include jellyfish, sea anemones, and corals, which exhibit these specific traits.

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  • 19. 

    Which of the following are used as evidence for evolution? I. Homologous structures II. Selective breeding of domesticated animals III. Overproduction of offspring

    • A.

      I and II only

    • B.

      I and III only

    • C.

      II and III only

    • D.

      I, II and III

    Correct Answer
    A. I and II only
    Explanation
    Homologous structures and selective breeding of domesticated animals are both used as evidence for evolution. Homologous structures are similar structures found in different species that suggest a common ancestor. This similarity indicates that these species have evolved from a common ancestor and have adapted to different environments over time. Selective breeding of domesticated animals also provides evidence for evolution as it demonstrates how humans have artificially selected certain traits and bred animals with those traits, leading to the development of new breeds. The overproduction of offspring, on the other hand, is not directly used as evidence for evolution but is a consequence of natural selection.

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  • 20. 

    Which of the following is correct for lipase? Substrate             Source                 pH optimum

    • A.

      Triglycerides        pancreas             pH = 8

    • B.

      Fatty acids         small intestine          pH = 7

    • C.

      Triglycerides    small intestine         pH = 9

    • D.

      Fatty acids         pancreas           pH = 9

    Correct Answer
    A. Triglycerides        pancreas             pH = 8
    Explanation
    Lipase is an enzyme that breaks down lipids, specifically triglycerides, into fatty acids and glycerol. It is primarily produced in the pancreas and is active in the small intestine. The pH optimum for lipase activity is 8, which means it functions most efficiently at a slightly alkaline pH. Therefore, the correct answer is "triglycerides, pancreas, pH = 8."

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  • 21. 

    What prevents antibiotics from being effective against viruses?

    • A.

      Viruses have a high rate of mutation.

    • B.

      Viruses have no RNA

    • C.

      Viruses have no metabolism.

    • D.

      Viruses have a protein shell that protects them.

    Correct Answer
    C. Viruses have no metabolism.
    Explanation
    Antibiotics work by targeting the metabolic processes of bacteria, which are different from those of viruses. Viruses do not have their own metabolism and rely on host cells to replicate. Therefore, antibiotics, which are designed to inhibit bacterial metabolic pathways, are not effective against viruses.

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  • 22. 

    The diagram below shows the human heart. What structures are indicated by the labels X, Y and Z? X                Y                 Z

    • A.

      Left atrium           aorta            semi-lunar valve

    • B.

      Left atrium            aorta              atrio-ventricular valve

    • C.

      Right atrium        pulmonary artery        atrio-ventricular valve

    • D.

      Right atrium          pulmonary artery           semi-lunar valve

    Correct Answer
    D. Right atrium          pulmonary artery           semi-lunar valve
    Explanation
    The labels X, Y, and Z indicate the following structures: right atrium, pulmonary artery, and semi-lunar valve, respectively.

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  • 23. 

    Which muscles contract to cause air to pass into the lungs through the trachea?

    • A.

      Internal intercostal muscles and diaphragm

    • B.

      Internal intercostal muscles and abdomen wall muscles

    • C.

      External intercostal muscles and diaphragm

    • D.

      External intercostal muscles and abdomen wall muscles

    Correct Answer
    C. External intercostal muscles and diapHragm
    Explanation
    The external intercostal muscles and diaphragm contract to cause air to pass into the lungs through the trachea. The external intercostal muscles are located between the ribs and play a role in elevating the ribcage during inhalation, while the diaphragm is a dome-shaped muscle located at the base of the lungs that contracts and flattens during inhalation, increasing the volume of the thoracic cavity and allowing air to enter the lungs. Together, these muscles work to expand the chest cavity and create a pressure gradient that draws air into the lungs.

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  • 24. 

    The diagram below shows the changes in membrane potential during an action potential. What occurs at the stages labelled 1 and 2?         1                                                           2

    • A.

      Na+ ions diffuse in;                                    K+ ions diffuse out;                                                          inside becomes more positive                     i nside becomes more negative

    • B.

      K+ ions diffuse out;                                 Na+ ions diffuse in; inside becomes more negative                inside becomes more positive

    • C.

      Na+ ions diffuse out;                                 K+ ions diffuse out; inside becomes more negative                 inside becomes more positive

    • D.

      Na+ ions diffuse in;                                K+ ions diffuse in; inside becomes more positive                inside becomes more negative

    Correct Answer
    A. Na+ ions diffuse in;                                    K+ ions diffuse out;                                                          inside becomes more positive                     i nside becomes more negative
    Explanation
    At stage 1, Na+ ions diffuse into the cell, causing the inside of the cell to become more positive. This is known as depolarization. At stage 2, K+ ions diffuse out of the cell, causing the inside of the cell to become more negative. This is known as repolarization.

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  • 25. 

    What are the roles of testosterone in males?

    • A.

      . Stimulation of FSH production and growth in puberty

    • B.

      Pre-natal development of genitalia and development of secondary sexual characteristics

    • C.

      Development of genitalia and pre-natal secondary sexual characteristics

    • D.

      Stimulation of FSH production and pre-natal development of secondary sexual characteristics

    Correct Answer
    B. Pre-natal development of genitalia and development of secondary sexual characteristics
    Explanation
    Testosterone plays a crucial role in the pre-natal development of male genitalia, such as the penis and testes. It is responsible for the differentiation and maturation of these reproductive organs. Additionally, testosterone is involved in the development of secondary sexual characteristics in males, including the deepening of the voice, growth of facial and body hair, and increased muscle mass. These characteristics typically emerge during puberty, when testosterone levels increase significantly.

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  • 26. 

    What is the reason for Okazaki fragments being formed during DNA replication?

    • A.

      To enable replication of the 3′ → 5′ (lagging) strand

    • B.

      To form the template for the RNA primers

    • C.

      To initiate replication on th. e 5′ → 3′ (leading) strand

    • D.

      To help the DNA helicase unwinding the DNA helix

    Correct Answer
    A. To enable replication of the 3′ → 5′ (lagging) strand
    Explanation
    Okazaki fragments are short, discontinuous DNA fragments that are formed on the lagging strand during DNA replication. This is because DNA replication occurs in a 5′ → 3′ direction, and the lagging strand is synthesized in the opposite direction. Therefore, the lagging strand is synthesized in short fragments, with each Okazaki fragment serving as a template for the synthesis of a new DNA strand. This allows for the efficient replication of the lagging strand and ensures that both strands of the DNA molecule are accurately replicated.

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  • 27. 

    Which is correct for the non-competitive inhibition of enzymes? Inhibitor resembles substrate                  Inhibitor binds toactive site

    • A.

                             yes                  yes

    • B.

                             yes                      no

    • C.

                             no                         yes

    • D.

                           no                            no

    Correct Answer
    D.                      no                            no
    Explanation
    Non-competitive inhibition occurs when the inhibitor molecule binds to a site on the enzyme other than the active site. This means that the inhibitor does not resemble the substrate, as it does not bind to the active site. In this case, both statements in the answer are "no", indicating that the correct answer is that the inhibitor does not resemble the substrate and does not bind to the active site.

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  • 28. 

    What is removed during the formation of mature RNA in eukaryotes?

    • A.

      Exons

    • B.

      Introns

    • C.

      Codons

    • D.

      Nucleosomes

    Correct Answer
    B. Introns
    Explanation
    During the formation of mature RNA in eukaryotes, introns are removed. Introns are non-coding sequences of DNA that are transcribed into RNA but are not involved in the synthesis of proteins. They are removed through a process called RNA splicing, where the introns are cut out and the remaining exons are joined together to form the mature RNA molecule. This process ensures that only the necessary coding sequences are present in the final RNA product, allowing for the synthesis of functional proteins.

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  • 29. 

    During glycolysis a hexose sugar is broken down to two pyruvate molecules. What is the correct sequence of stages?

    • A.

      Phosphorylation → oxidation → lysis

    • B.

      Oxidation → phosphorylation → lysis

    • C.

      Phosphorylation → lysis → oxidation

    • D.

      Lysis → oxidation → phosphorylation

    Correct Answer
    C. pHospHorylation → lysis → oxidation
  • 30. 

    Where are the light-dependent and light-independent reactions taking place in the diagram below? Light-dependent                           Light-independent I

    • A.

                       I                          IV

    • B.

      II III

    • C.

      III II

    • D.

      IV I

    Correct Answer
    A.                  I                          IV
  • 31. 

    What are differences between monocotyledonous and dicotyledonous plants? Monocotyledonous Dicotyledonous

    • A.

      Parallel venation;                                                  net-like venation; floral organs in multiples of 4 or 5                        floral organs in multiples of 3

    • B.

      . net-like venation;                                                parallel venation;                                      floral   organs in multiples of 3                        floral organs in multiples of 4 or 5                                                                                             

    • C.

      Net-like venation;                                                    parallel venation; floral organs in multiples of 4 or 5                         floral organs in multiples of 3

    • D.

      Parallel venation;                                            net-like venation; floral organs in multiples of 3                         floral organs in multiples of 4 or 5

    Correct Answer
    D. Parallel venation;                                            net-like venation; floral organs in multiples of 3                         floral organs in multiples of 4 or 5
    Explanation
    Monocotyledonous plants have parallel venation in their leaves, while dicotyledonous plants have net-like venation. Monocots have floral organs in multiples of 3, while dicots have floral organs in multiples of 4 or 5. Therefore, the correct answer is parallel venation; net-like venation; floral organs in multiples of 3; floral organs in multiples of 4 or 5.

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  • 32. 

    The diagram below shows part of the vascular system of a dicotyledonous plant. Which process is indicated by the arrows?

    • A.

      Passive translocation in the phloem of sucrose from the sink to the source

    • B.

      Active translocation in the phloem of sucrose from the source to the sink

    • C.

      Passive translocation in the xylem of sucrose from the sink to the source

    • D.

      Active translocation in the xylem of sucrose from the source to the sink

    Correct Answer
    B. Active translocation in the pHloem of sucrose from the source to the sink
    Explanation
    The arrows in the diagram indicate the process of active translocation in the phloem of sucrose from the source to the sink. This means that the plant is actively moving sucrose from where it is produced (source) to where it is needed or stored (sink). This process requires energy and is facilitated by specialized cells called sieve tube elements and companion cells. The phloem is responsible for the transportation of organic nutrients, such as sugars, throughout the plant.

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  • 33. 

    What controls the flowering process in long-day plants?

    • A.

      Pfr is converted by red light to Pr which acts as a promoter of flowering.

    • B.

      Pr is converted by red light to Pfr which acts as an inhibitor of flowering.

    • C.

      Pr is converted by red light to Pfr which acts as a promoter of flowering.

    • D.

      Pfr is converted by red light to Pr which acts as an inhibitor of flowering.

    Correct Answer
    C. Pr is converted by red light to Pfr which acts as a promoter of flowering.
  • 34. 

    A test cross resulted in these recombinants: Which of the following was the parental test cross?

    Correct Answer
    A.
  • 35. 

    What occurs during the blood clotting process?

    • A.

      . Prothrombin is converted into thrombin which acts on fibrinogen.

    • B.

      Prothrombin is converted into thrombin which acts on fibrin.

    • C.

      Fibrinogen is converted into fibrin which acts on prothrombin.

    • D.

      Fibrinogen is converted into fibrin which acts on thrombin.

    Correct Answer
    A. . Prothrombin is converted into thrombin which acts on fibrinogen.
    Explanation
    During the blood clotting process, prothrombin is converted into thrombin. Thrombin then acts on fibrinogen, converting it into fibrin. Fibrin forms a mesh-like network that traps platelets and red blood cells, forming a blood clot to stop bleeding.

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  • 36. 

    What is indicated by the letters X, Y and Z?          X                      Y                   Z

    • A.

           sarcomere                myosin filaments                  actin filaments

    • B.

        sarcomere                     actin filaments                    myosin filaments

    • C.

        dark band              myosin filaments                         actin filaments

    • D.

        dark band                 actin filaments                              myosin filaments

    Correct Answer
    D.   dark band                 actin filaments                              myosin filaments
    Explanation
    The letters X, Y, and Z indicate the components of a sarcomere, which is the basic unit of a muscle fiber. X represents the dark band, which is also known as the A band and is composed of overlapping myosin filaments. Y represents actin filaments, which are thin filaments that extend into the A band. Z represents the light band, which is also known as the I band and contains only actin filaments. Therefore, the correct answer is the dark band, actin filaments, and myosin filaments.

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  • 37. 

    The diagram below shows some stages in the production of monoclonal antibodies. What are stages X, Y and Z?         X                                Y                                    Z

    • A.

      Injection of antibody        isolation of B-cell      fusion between B-cell and tumour cell                                                                         resulting in plasma cell

    • B.

      . injection of antibody        isolation of T-cell        fusion between T-cell and tumour cell                                                                                resulting in plasma cell

    • C.

      Injection of antigen      isolation of T-cell           fusion between T-cell and tumour cell                                                                             resulting in hybridoma cell

    • D.

      Injection of antigen       isolation of B-cell              fusion between B-cell                                                                               and tumour cell resulting in hybridoma cell

    Correct Answer
    D. Injection of antigen       isolation of B-cell              fusion between B-cell                                                                               and tumour cell resulting in hybridoma cell
  • 38. 

    In the diagram of the nephron below, what structures are indicated by the letters Y and Z?      Y                                      Z

    • A.

      Glomerulus                      collecting duct

    • B.

      Bowman’s capsule               collecting duct

    • C.

      Bowman’s capsule               distal convoluted tubule

    • D.

         glomerulus                          distal convoluted tubule

    Correct Answer
    C. Bowman’s capsule               distal convoluted tubule
    Explanation
    In the given diagram, the structure indicated by the letter Y is Bowman's capsule. This is supported by the fact that Bowman's capsule is listed as an option directly below the letter Y. Similarly, the structure indicated by the letter Z is the distal convoluted tubule, as it is the only option listed directly below the letter Z.

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  • 39. 

    What are the roles of the following structures in the production of semen?           Epididymis                Seminal vesicle                       Prostate gland

    • A.

      Production of a fluid         production of fructose             maturation of sperm containing alkaline minerals

    • B.

      Maturation of sperm          production of a fluid              production of fructose                                            containing citric acid

    • C.

      Maturation of sperm            production of fructose               production of a fluid                                                                                               containing alkaline                                                                                                     minerals

    • D.

      Production of a fluid          maturation of sperm                  production of fructose containing alkaline minerals

    Correct Answer
    C. Maturation of sperm            production of fructose               production of a fluid                                                                                               containing alkaline                                                                                                     minerals
    Explanation
    The epididymis is responsible for the maturation of sperm. The seminal vesicle produces a fluid that contains fructose, which provides energy for the sperm. The prostate gland also produces a fluid that nourishes and protects the sperm. It contains citric acid, which is important for the overall composition of semen.

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  • 40. 

    What is the role of HCG in early pregnancy?

    • A.

      It prevents the degeneration of the corpus luteum.

    • B.

      It initiates the development of the uterus lining.

    • C.

      It inhibits the production of estrogen.

    • D.

      It stimulates the degeneration of the corpus luteum.

    Correct Answer
    A. It prevents the degeneration of the corpus luteum.
    Explanation
    HCG, or human chorionic gonadotropin, plays a crucial role in early pregnancy by preventing the degeneration of the corpus luteum. The corpus luteum is a temporary structure that forms in the ovary after ovulation and produces progesterone, which is essential for maintaining the uterine lining and supporting a pregnancy. HCG acts as a signal to the corpus luteum to continue producing progesterone, ensuring the survival of the pregnancy. Without HCG, the corpus luteum would degenerate, leading to a decrease in progesterone levels and the potential loss of the pregnancy.

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Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 22, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Feb 21, 2012
    Quiz Created by
    Shefali
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