Latest Biological Science Reviewer 3 - LET EXAM - Questions & Answers

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Latest Biological Science Reviewer 3


1. Which organ has strong muscular walls where fetus develops into an individual?

A. Birth canal
B. Cevix
C. Ovary
D. Uterus

Ans: D. Uterus
- The Uterus or most commonly known as womb is a hollow muscular organ located in the female pelvis between the bladder and return. The ovaries produce the eggs that travel through the fallopian tubes. Once egg has left the ovary it can be fertilized and implant itself in the lining of the uterus. The mian function of the uterus is to nourish the developing fetus prior to birth.

2. Which statement is FALSE about male and female reproduction?

A. Both systems experience latent development
B. Both sexes develop from similar embryonic tissue
C. Both reproduction systems have gonads that produce gametes
D. Both sexes have reproductive capabilities throughout adulthood

Ans: D. Both sexes have reproductive capabilities throughout adulthood
- Both male and female reproductive systems experience maturation of their reproductive organs, which becomes functional during puberty as a result of the gonalds secreting sex hormones. However the reproductive capabilities of both sexes are not all throughout adulthood. At age’s 40’s to 50’s women experience menopause when he function of the ovaries ceases. Andropause, the male menopause is a condition is a condition that is associated with the decrease in the hormone testosterone.

3. Which pair of body systems works most closely together?

A. Skeletal and Digestive
B. Circulatory and Muscular
C. Integumentary and Nervous
D. Respiratory and Endocrine

Ans: C. Integumentary and Nervous
- The Integumentary system is also home to millions of nerves that responds to touch pressure and pairs of body system that work closely together include digestive and excretory, cardiovascular and respiratory  system functions together to maintain homeostatis.

4. What is the primary  cause of food indigestion?

A. Infection
B. Excess stomach acid
C. Lack of chewing
D. Lack of water in the body

Ans: C. Lack of chewing
- Eating too much , eating too fast, eating high-fat foods or eating during stressfull situation drinking, drinking too much alcohol and cigarette smking are some of the common reason of indigestion.


5. Which is a lung condition that causes shortness of breath to over-inflation of the aveoli?

A. Asthma
B. Bronchitis
C. Emphysema
D. Tuberculosis

Ans: C. Emphysema
- Emphysema is a long term, progressive disease of the lungs that causes shortness of breath. In people with emphysema the air sacs in the lungs (alveoli) are damaged. The most common cause of emphysema is smoking. Asthma is a chronic disease involving the airways in the lungs. This can make breathing difficult and trigger coughing, wheezing and shortness of breach. Bronchitis often cough up thickened mucus, which can be discolored. Tuberculosis (TB) is a contagious disease caused by the bacterium, Mycobacterium tuberculosis (MTB) that attacks the lungs.

6. What is hypoglycemia?

A. A metabolic disease in which the person has high blood glucose
B. A condition characterized by an abnormally low level of blood sugar
C. A tumor in the pancreas that results in the overproduction of glucagon
D. A disorder in which the thyroid gland does not produce enough thyroid hormone

Ans: B. A condition characterized by an abnormally low level of blood sugar
- Hypoglycemia also known a low blood glucose or low blood sugar, occurs when the level of glucose in the blood drops below normal. Choice A is diabetes. Choice C is glucagonoma. Choice D is hypothyroidism.

7. Which is NOT a step in preparing a herbal infusion?

A. Boil the water
B. Slimmer the herb
C. Strain the herb
D. Pour boiling water onto the herb

Ans: B. Slimmer the herb
- Infusions are used to extract vitamins and volatile ingredients from soft ingredients like leaves, flowers. It is commonly done by just pouring boiling water onto the herb. A decoction is used to extract primarily the mineral salts and bitter principles of plants from hard material such as roots bark, seeds and wood. The word “decoct” means to concentrate by boiling.

8. Which is the appropriate method of preparing a ginger tea or salabat?

A. Decoction
B. Infusion
C. Poultice
D. Combination of A, B & C

Ans: Decoction
- In making ginger tea or salabat a decotion of ginger is slowly cooked with sugar until the syrupy mixture crystallizes and dries up.

9. Which revolution the manner in which the body can be scanned in order to detect disease like cancer and inform treatment in a range of range disease areas?

A. Dialysis
B. Laparoscopic Surgery
C. Magnetic Resonance Imaging
D. X-ray

Ans: C. Magnetic Resonance Imaging
- Magnetic resonance imaging (MRL) of the body uses a power full magnetic field, radio waves and a computer to produce detailed pictures of the inside of your body. It may be used to help diagnose or monitor treatment for a variety of conditions within the chest abdomen and pelvis. Dialysis is a procedure to remove waste products and excess fluid from the blood when the kidney stop working properly. Laparoscopy is a surgical diagnostic procedure used to examine the organs inside the abdomen it is a low-risk, minimally invasive process in which operation are performed far from their location through small incision elsewhere in the body.

10. When patient is suffering from coronary heart disease wherein the artery has blockage, what surgical technique is advisable to improve condition?

A. Angioplasty
B. Biopsy
C. Endoscopy
D. Stem Cell therapy

Ans: A. Angioplasty
- Angioplasty is a procedure to restore blood flow to the heart usually by implanting a stent in a blocked artery.A biopsy is the removal of a small amount of tissue from the body in order to examine it more closely. An endoscopy is a procedure where the inside of your body is examined using specialized instruments to view and operate on the internal organs and vessel of the body. Stem-cell therapy is the use of stem cells to treat or prevent a disease or condition. It is commonly used in bone marrow transplantation and in treating certain blood and immune system disorders.


11. Your topic is about population growth. You would like your students to visualize world population growth from 1510 to 2010. Which instructional material will you use?

A. Hypercard
B. Microcomputer-Based Laboratory
C. Simulation
D. Video

Ans: C. Simulation
- Through stimulation students can experience changes in world population by creating a timeline that depicts world population doubling throughout history by actively simulating world population growth from 1510- 2010.

12. Which of the following will you use to have a clearer image of individual bacteria strands?

A. Low Power Objective
B. High Power Objective
C. Oil immersion Objective
D. Any of the above
Ans: C. Oil immersion Objective

- By placing a substance such as immersion oil with a refractive index equal to that of the glass slide in the space filled with air, more light is directed through the objective and a clearer image is observed. Immersion oil is best for viewing samples that are dead or not moving protists can occasionally be viewed with immersion oil, but the best specimes for oil immersion do not move. Oil  immersion is required when viewing individual bacteria strands or details of striations in skeletal muscle.

13. What are the correct steps in making  a wet mount?

I. Place an object on the slide using tweezers.
II. Place the wet mount on the stage of the microscope
III. Put one drop of water on the slide
IV. Lower the cover glass slowly to avoid air pockets, pull the tweezers out.

A. I-II-III-V
B. III-I-II-IV
C. IV-III-I-II
D. III-I-IV-II

Ans: D. III-I-IV-II
- In a wet mount the specimen on a microscope slide is to get better view of the spicemen is placed in a drop of water or other liquid held between the slides and the cover slip by surface tension. The water improves the image quality and also supports the specimen. The correct way of doing it is choice D.

14. What is the first step in staining a specimen on a microscope slide?

A. Adding chemical fixative
B. Applying an appropriate stain
C. Treating the sample with a surfactant
D. Mounting the sample on a microscope slide


Ans: C. Treating the sample with a surfactant
- The main purpose of staining a specimen on a microscopic slide is to get a better view. Of specimen. The stain usually colors one part of the specimen, but not another part. By creating that color contrast it becomes easier to view parts of the subject. The first step is permeabilization, which is when the sample is treated with a surfactant. This chemical breaks down cell walls and allows in larger molecules of dye.  The next step is fixation where a chemical fixative is added which will create chemical bonds between proteins and enhance their rigidity. The samples must then be mounted on a microscope slide, the samples may be grown directly on the slide. The last step is applying an appropriate stain which color cells, tissues and components.

15. Which method of microscope sample placing is appropriate if the sample is pollen?

A. Dry Mount
B. Wet mount
C. Smear Slides
D. Squash Slides

Ans: A. Dry Mount
- Dry mount require a blank microscope slide, a glass cover slip and a noun moisture based specimen. Examples of dry mount slides include insects legs, flower petals, power or substances such as grains  of sand or dry chemical, dirt samples and even newsprint. Wet mount slides are used to view liquids under the microscope. Wet mount slide samples might include pond water, cheek cells blood or sperm sample. The purpose of making a smear is to fix the bacteria onto the slide and to prevent the sample from being lost during a staining procedure. Squash sliding is used for soft samples.

16. Which may be a replacement for burette when used for titration?

A. Disposable syringe
B. Eppendorf cup
C. Plastic spot plate
D. Snap-lid glass

Ans: Medical disposable syring may be used as a replacement for pipettes and burettes in a microscale titration. The disposable syringe has a transparent cylinder with well read graduation, which is smudge-proof. When using disposable syringes as burette replacements, liquids must be filled in the syringe without any air bubbles. For this purpose first some liquid is taken up with syringe and then abruptly forced out again. If this process is repeated several times, the bubble-free filling of the syringe can be managed. Slow charging and discharging is possible with these syringes.

17. Which of the following can serve as alternative for petri dishes and spot plates?

I. Tin can
II. Plastic
III. Empty pill package
IV. Container of cosmetic product

A. I only
B. I and II only
C. I, II and III only
D. I, II, III and IV

Ans: D. I, II, III and IV
- Empty package material which produce in many households as waste products, can also be used as rection chambers for chemical and physical experimental. For instance the use of empty pill package, glass, tin, plastic cups, or containers of cosmetic products are very well suited. These empty pill package also have the same benefits as the multiwellplates. Once the aluminum foil is removed from the drug package all the expirements, which can be conducted in spot plates, can also be conducted in a empty pill package. If larger capacity than the capacity than the capacity provide by the empty provided by the empty drug package is required, glass (e.g cleaned jam or honey jar ), or plastic cups can alternatively be usd as reaction vessels.

18. Plants are classified as herbs, shrubs and trees. What is the basis in this biological classification?

A. Evolutionary relationship
B. Gene pool
C. Morphology
D. Phylogenetics

Ans:  C. Morphology
-Morphology forms the primary basis for classifying organism into various taxonomic groups of taxa. It deals with the structure or the physical appearance of the organisms. The similarities in the morphological characters are used for grouping the plants together as herbs, shrubs, vines and trees. Phylogenetics is the study of evolutionary relationship among the species.

19. Which of the following statements is TRUE?

A. Prokaryotic cells came before Eukaryotes cells
B. Prokaryotic cells are bigger than Eukaryotic cells
C. Eukaryotic cells are simple, Prokaryotic cells are complex
D. Eukaryotic cells do not have nucleus, prokaryotic cells do.

Ans: A. Prokaryotic cells came before Eukaryotes cells
- Prokaryotic cells are often thought to be the first life on the planet. Evidence supports the idea that eukaryotes cells are actually the descendants of separate prokaryotic cells that joined together in a symbolic.

20 In a laboratory experiment design to demonstrate one aspect of photosynthesis, three test tubes were treated as shown above. The test tubes were then placed under a bright lamp for 24 hours. Which of the following is the best explanation for the observed color change in tube 2?

A. The aquatic plant used carbon dioxide, raising the pH of the solution
B. The light bleached the solution from its original color of yellow to blue
C. The light plant produce oxygen during photosynthesis which caused the color change
D. The aquatic plant produced carbon dioxide, which change into carbonic acid and caused color change.

Ans: D. The aquatic plant produced carbon dioxide, which change into carbonic acid and caused color change.
- Bromothyle blue can be used as an indicator of CO₂ concentration. CO₂ dissolves in solution and a small percent becomes carbonic acid. Plants utilize CO2 during photosynthesis, thus raising the pH of the solution and changing the color of the solution from yellow to blue.

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