Test 3.
c) Oxidoreductase
Which of the following enzymes catalyze the transfer of electrons or hydrogen atoms from one molecules to another? a) Hydrolase b) Ligase c) Oxidoreductase d) Transferase
a) Turtle and snake Organisms are classified into hierarchies which are based on their relativity with one another. The Kingdom is the highest level in the classification of living things. The yeast and mushroom belong to Kingdom Fungi. The shark and the milkfish belong to Kingdom Animalia and Phylum Chordata. The turtle and snake are classified under Kingdom Animalia, Phylum Chordata, and Class Reptilia. Bread mold and water mold are not related since they belong to two different kingdoms, Fungi and Protista, respectively.
Based on the taxonomic classification of organisms, which of the following pairs of organisms is mostly related? a) Turtle and snake b) Shark and milkfish c) Yeast and mushroom d) Water mold and bread mold
d) Nucleus located at the center of the cell
Which of the following describes the muscles in the blood vessels? a) Striated b) Elongated c) Multinucleated d) Nucleus located at the center of the cell
b) 28 chromosomes Meiosis is a special types of cell division responsible for the formation of gametes or sex cells. The result is four cells with half the ploidy number of the mother cell. During prophase 1, synapsis and crossing over occur. The number of chromosomes will only be reduced to half at the end of meiosis 1.
A diploid cell has 28 chromosomes. When meiosis occurs, how many chromosomes are there during Prophase I? a) 14 chromosomes b) 28 chromosomes c) 56 chromosomes d) 84 chromosomes
d) II, IV, V, III and I Primary ecological succession begins in an essentially lifeless area where soil has not yet formed, such as on a new volcanic island, or on the rubble left behind by a retreating glacier. In the case of glaciers, which are still shrinking in places like Glacier bay, Alaska, the barren ground is first occupied by mosses and lichens, and then by dwarf willows. After about 50 years, alders from dense stands. These eventually give way to Sitka spruce, which are later joined by hemlock, forming the relatively stable spruce-hemlock forest that we recognize today as taiga.
Arrange the following events according to sequence during a primary ecological succession. I. Spruce-Hemlock forest II. A rubble left behind by a retreating glacier III. Alders form dense stands IV. Accumulation of mosses and lichens V. Formation of dwarf willows a) I, II, III, IV and V b) V, IV, III, II and I c) I, III, II, IV and V d) II, IV, V, III and I
b) Mitochondria > Sperm > Cornea > Gluteus Maximus Atoms - molecules - cells (mitochondria, sperm) - tissues (cornea) - organs (gluteus maximus) - organ system.
Arrange the following in increasing levels of complexity: Sperm, Mitochondria, Cornea, Gluteus Maximus a) Sperm > Mitochondria > Cornea > Gluteus Maximus b) Mitochondria > Sperm > Cornea > Gluteus Maximus c) Mitochondria > Sperm > Gluteus Maximus > Cornea d) Sperm > Mitochondria > Gluteus Maximus > Cornea
d) Gametogenesis - fertilization - cleavage - gastrulation - organogenesis - growth and histological differentiation The process of development of a new individual starts before the fertilization of the egg. The egg and the sperm are produced during gamete formation, followed by penetration of the sperm into the egg (fertilization), forming the zygote. To form a multicellular organism, the zygote undergoes a sequence of cell division (cleavage). the formation of germ layers will develop into different tissues and organs (organogenesis). further, the cells of each organ begin to grow and differentiate from other cells until the cell acquire the structure and function needed to execute the task of the organ (growth and differentiation).
Developmental biology deals with the study of the development of animals. It also deals with the processes involved in the transformation of fertilized egg to a more complex individual. Which of the following is the correct sequence of the development of a simple cell to a more complex organism? a) Fertilization - gametogenesis - gastrulation - cleavage - organogenesis - growth and histological differentiation b) Gametogenesis - fertilization - cleavage - gastrulation - growth and histological differentiation - organogenesis c) Fertilization - gametogenesis - cleavage - gastrulation - growth and histological differentiation - organogenesis d) Gametogenesis - fertilization - cleavage - gastrulation - organogenesis - growth and histological differentiation
a) Lowering activation energy of the reaction
Enzymes hasten chemical reactions by a) Lowering activation energy of the reaction b) Decreasing number of products needed to drive the reaction forward c) Inactivating inhibitors which slow down reactions d) Harness high energies and releases it to the reaction
b) Digestion of fats will be slowed down due to bile obstruction. Bile is essential for digesting fats. Removal of the bile duct will cause fat digestion to slow down
If the bile duct is resected or removed, what will be its effect on digestion? a) Digestion of fats will be slowed down due to lack of pancreatic lipase b) Digestion of fats will be slowed down due to bile obstruction c) Digestion of fats will be slowed down due to gallbladder obstruction d) Digestion of fats will not be affected
a) Snakes Magnification occurs because the biomass at any given trophic level is produced from a much larger biomass ingested from the level below. Thus, top-level carnivores tend to be the organisms most severely affected by the toxic compounds that have been released into the environment.
In the process of biological magnification, toxins that are harmful become more concentrated in the succesive trophic levels of a food web. The pesticides dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenols (PCBs) are well-known examples of this. Which of the following organisms will receive the most concentration of these harmful substances in their body system? a) Snakes b) Small fishes c) Zooplanktons d) Fish-eating birds
c) Nucleic acids Linkages in carbohydrates have glycosidic bonds and in proteins, peptide bonds. Nucleic acids have phosphodiester bonds and hydrogen bond. Only nucleic acids have an ester linkage on the choices.
Among the choices, which macromolecules uses ester linkages? a) Carbohydrates b) Proteins c) Nucleic acids d) All of the above
a) It will crenate. In a hypertonic environment, the cell has a lower concentration of solutes, and therefore it also has a higher water potential than the surrounding extracellular fluid. Osmosis causes a net movement of water out of the cell, causing the cytoplasm to decrease in volume, resulting for the cell to shrink (crenate) and forms abnormal notches around its edges. The effect of crenation are visible in red blood cells (erythrocytes), as they become distorted in shape rather than maintaining the usual disc-like, dimpled shape.
An eythrocyte is placed in a beaker with a hypertonic solution. What do you think will happen to the cell after several minutes? a) It will crenate. b) It will plasmolyze. c) It will become turgid. d) It will become flaccid.
c) There is no chance that the offspring will have blue-colored pupils and wavy hair. 8/16 BbHH (black-colored pupil, straight hair) 8/16 BbHh (black-colored pupil, wavy hair) The chance that the offspring will have blue-colored pupils and wavy hair (bbHh) is 0%.
Incomplete dominance is characterized by a cross between homozygous dominant and recessive genes that will result in an intermediate trait. Assume the following sets of genes in a human being: B - black-colored pupil Bb - blue-colored pupil HH - straight hair Hh - wavy hair hh - curly hair A husband and wife, BBHH x bbHh, wants to know the probability of having a child with blue-colored pupil and wacy hair. What will you tell them? a) There is a 1/4 chance that the offspring will have blue-colored pupils and wavy hair. b) There is a 1/2 chance that the offspring will have blue-colored pupils and wavy hair. c) There is no chance that the offspring will have blue-colored pupils and wavy hair. d.) Impossible to determine.
c) Humoral immune defense B lymphocytes is a kind of lymphocytes that secretes antibodies for humoral immune response, where it binds to the antigen and eventually destroys it. A cell-mediated response is accomplished by T-lymphocytes and it involves attacking the virally infected cells and cancer cells.
Lymphocytes, a subclass of white blood cells, are divided into two types: B lymphocytes and T-lymphocytes. What is the role of B lymphocytes? a) Chemical defense b) non-specific defense c) Humoral immune defense d) Cell-mediated immune defense
a) Zinc Macronutrients include oxygen, carbon, hydrogen, nitrogen, potassium, calcium, magnesium, phosphorus, and sulfur.
Macronutrients are elements needed by plants in relatively large amount. All of the following are macronutrients except ______. a) Zinc b) Nitrogen c) Potassium d) Phosphorus
b) Frameshift mutations The whole frame of the genetic sequence is changed, while in a point mutation only one nucleotide is modified to become another nucleotide.
Mutation is the alteration of the form of a particular gene or chromosome that results in new trait to be inherited. Mutations can occur in chromosome structure or chromosome number. Several types of gene mutations may occur, such as insertion and deletion. Here are examples of changes applied in a sentence: Insertion of "I" THE CAT AND DOG RUN THE CAI TAN DDO GRU N Deletion of "E" THE CAT AND DOG RUN THC ATA NDD OGR UN From the given examples, we can classify these mutations as, a) Point mutations b) Frameshift mutations c) Carcinogenic mutations d) None of the choices
a) 3
Oogenesis is the meiosis that occurs in the ovary of female organisms. If 5 oogonia are present, how many active egg cells are produced when 3 out of 5 oogonia undergo oogenesis? a) 3 c) 6 b) 5 d) 10
c) I, II, and IV Statement III is false because after the cell differentiated, it must be metabolically active to perform its function for a specific organ.
Organogenesis is the process involved in the formation of organs. Along with this process, the cells choose to become a particular type of cell that will function for a specific organ. This process is called differentiation. Which of the following statements are true about a differentiated cell? I. A differentiated cell utilizes a particular set of proteins to perform its function. II. Cells that are differentiated assume a specific shape to function effectively to the tissue it belongs. III. When the cell differentiates, it deactivates for some time to regenerate the energy and materials spent during differentiation. IV. Muscle cells, nerve cells, and red blood cells are examples of differentiated cells. a) I and II b) I, II, and III c) I, II, and IV d) All of the choices
b) corpus luteum Corpus luteum comes from a ruptured follicle that is repaired and turned yellowish. It secretes a hormone called progesterone, which inhibits the follicle-stimulating hormone, thus preparing the uterus for pregnancy. The infundibulum is a funnel-shaped distal end of each uterine tube (fallopian tube). The Graafian follicle is a mature ovarian follicle. The seminiferous tubule is the site of spermatogenesis.
Progesterone is a substance that prepares the endometrium in the uterus for implantation of fertilized egg. Where is this substance secreted? a) infundibulum b) corpus luteum c) Graafian follicle d) seminiferous tubule
D. 5' AGT TGG TGG TGA GGC GTC GGC CAG GCT 3' The amino acid sequence in position 29 is CCT which codes for amino acid Proline. Replacing CCT with amino acid sequence GTC which codes for Valine makes the DNA sequence mutant.
The DNA sequence below shows the segment of the gene for human hemoglobin starting with amino acid residue 24. Normal: 5' AGT TGG TGG TGA GGC CCT GGC CAG GCT 3' Which of the following amino acid sequence will change the proline at position 29 to valine, making the sequence mutant? Use the following amino acid sequence: Valine - GTT, GTC Arginine - AGA, AGG Alanine - GCT, GCC Proline - CCT, CGA A. 3' AGT TGG TGG GTT GGC CCT GGC CAG GCT 5' B. 5' AGT TGG GTC TGA GGC CCT GGC CAG GCT 3' C. 3' AGT TGG TGG TGA GGC GTC GGC CAG GCT 5' D. 5' AGT TGG TGG TGA GGC GTC GGC CAG GCT 3'
b) Centriole Both plant and animal cells have cell membranes and nucleus. The centriole can be found only in animal cells and the cell wall is exclusive to plant cells.
The dwarf water buffalo and the maple tree have eukaryotic type of cells. Which of the following organelles is present in the cells of the dwarf water buffalo but absent in the cells of the maple tree? a) Nucleus b) Centriole c) Cell wall d) Cell membrane
b) They have the most amount of energy available The position of organisms in an energy pyramid would suggest the amount of energy available. Producers are placed on the base of the energy pyramid because they have the large quantity of energy available by being the organism that can convert light energy into chemical energy.
The energy pyramid shows the decreasing pattern of energy from producers to consumers and from one tophic level to another. Producers are placed at the base of the energy pyramid because ________. a) They are used up at a faster rate b) They have the most amount of energy available c) They can be found in aquatic and terrestrial ecosystem d) They have pigments available in producing their own food
d) 16% T, 24% G, 32% A, and 28% C Complementary bases are A-T and G-C. the percentage of each of the nitrogen-containing base is equal to the percentage of their complementary.
The structure of DNA can be described as a double strand twisted with one another to form a spiral staircase. One chain of DNA strand contains 16% A, 24% C, 32% T, and 28% G. What will be the composition of the complementary chain? a) 32% T, 12% G, 16% A, and 56% C b) 32% A, 12% C, 16% T, and 56% C c) 16% A, 24% C, 32% T, and 28% C d) 16% T, 24% G, 32% A, and 28% C
a) 25%
Vitiligo is a disorder in which melanocytes (cells that produce melanin pigment) are unable to function. As a result, white patches appear on the skin. Albinism is a chromosomal mutation that may result in the cessation of melanin production or a considerable decline in the amount of melanin. A man who is an intermediate albino (Aa) with vitiligo (Bb) marries a woman who is an albino (aa) but has a normal skin (bb). What percent of their offspring is considered as purebred? a) 25% b) 50% c) 75% d) 100%
b) Left ventricle conveys blood from the heart to all the parts of the body The muscles of the ventricle is more thicker than that of the atria because these chambers are responsible for pumping of blood to the anterior and posterior portion of the body.
What could be the possible reason why the left ventricle is thicker that the right atrium? a) Left ventricle has muscle cells with multiple mitochondria b) Left ventricle conveys blood from the heart to all the parts of the body c) Left ventricle experiences more pressure from the pericardial cavity d) Left ventricle has an additional layer of muscle
d) DNA synthesis will slow down to tolerate DNA damage and suppress genomic instability. This is to stop propagating errors.
What will happen in the cell cycle if damaged DNA is detected in the intra-S checkpoint? a) The cell will undergo apoptosis. b) The activation of the checkpoint will trigger the release of the p53 protein. c) The cell will enter a resting phase either permanently or until conditions improve. d) DNA synthesis will slow down to tolerate DNA damage and suppress genomic instability.
c) An apple with a beaker of an ethylene-releasing chemical in a plastic bag. The beaker with an ethylene-releasing chemical in a plastic bag will supply more ethylene than choice (b). Choice (a) will inhibit the action of ethylene by preventing ethylene from accumulating.
Which of the following apples will ripen the fastest? a) An apple often flushed with carbon dioxide b) An apple with an ethylene-releasing banana enclosed in a bag c) An apple with a beaker of an ethylene-releasing chemical in a plastic bag d) Choices b and c
a) Primary xylem Correct order from the outside to the inside of a woody eudicot stem : cortex - primary phloem - secondary phloem - vascular cambium - secondary xylem - primary xylem - pith.
Which of the following is closest to the center of a woody eudicot stem? a) Primary xylem b) Secondary phloem c) Secondary xylem d) Secondary phloem
c) Development of the neural crest The development of the neutral crest happens after the formation of the three germ layers. It is actually derived from the ectoderm.
Which of the following is not achieved by the cell after cleavage? a) Formation of blastula b) Increase in cell number c) Development of the neural crest d) Increase in the amount of genetic material
d) Carbon dioxide Traffic molecules across the membrane: 1. Small polar uncharged molecules such as water and carbon dioxide will easily pass 2. Hydrophobic molecules such as hydrocardons and oxygen can cross with ease because they can dissolve in the lipid bilayer 3. Large polar uncharged molecules such as proteins and sugars will not pass; 4. Ions such as H+, Na+, Cl-. K+ will not readily pass, they need transport proteins or channels
Which of the following substances will easily cross the cell membrane? a) Starch b) Sodium ion c) Chloride ion d) Carbon dioxide