LET Reviewer in BIOLOGICAL SCIENCE Part 1

Majorship LET Reviewer

LET Reviewer for Biological Science

PRACTICE TEST IN BIOLOGICAL SCIENCE

1. Which type of cytoskeletal structure is involved in flagella formation?
a. Microtrabecule
b. Intermediate filament
c. Microfilament
d. Microtubule

2. Compounds with the same chemical formula but with different structural formula are called _____________.
a. polymer
b. double stranded
c. isomer
d. helices

3. Which are small, irregularly-shaped cells without nuclei but are rich in ATP?
a. Leukocyte
b. Thrombocytes
c. Lymphocytes
d. Erythrocytes

4. Why can an eighty-seven percent (87%) salt solution keep a frog tissue alive for observation? Because its osmotic pressure is
a. less than that of the cell
b. equal to that of the cell
c. varied
d. greater than that of the cell

5. What type of muscle tissue lines hollow structures like ducts and blood vessels that contracts involuntarily?
a. Skeletal
b. Cardiac
c. Striated
d. Smooth

6. Which characteristic of cancer cells differentiates them from normal cells?
a. Cancer cells continue to divide even when they are tightly packed
b. Cancer cells are unable to synthesize DNA
c. Cancer cells undergo indirect cell division
d. The cell cycle of cancer cells is arrested in the S phase

7. Studying the characteristic structure and functions of all kinds of cells entails investigations in _____________.
a. cytology
b. morphology
c. embryology
d. histology

8. How many ATP molecules are produced via oxidative phosphorylation when one (1) mole of glucose is degraded into carbon dioxide and water?
a. 4
b. 24
c. 34
d. 6

9. Which of the following exemplifies phagocytic feeding?
a. Red blood cells
b. Virus
c. Platelets
d. White blood cells

10. Which tissue in all vascular plants has food transport as its main function?
a. Sclerenchyma
b. Palisade
c. Phloem
d. Xylem

11. Which is the 3-carbon sugar formed during the dark reaction phase of photosynthesis?
a. PGAL
b. ADP
c. ATP
d. NADPH

12. A leaf could be identified either as dicot or monocot by _____________.
a. pressing whether soft or hard
b. looking at the shape and size
c. examining venation
d. looking at the stomata

13. Which hormone stimulates the growth of lateral buds and sprouts on branches of trees?
a. Cytokinin
b. Auxin
c. Abscissic acid
d. Gibberelin

14. “Leaf fall” which regularly occurs during winter months, resulting in the separation of layers near the base of the petiole is a condition called _____________.
a. annual sheds
b. senescence
c. abscission
d. dormancy

15. Which part of a seed appears as a scar which marks the entry of the pollen tube during fertilization?
a. Epicotyl
b. Tegmen
c. Testa
d. Hilum

16. Which of the following is a part of the process of chemiosmosis?
a. Build up of hydrogen ion concentration
b. Absorption of light energy by chloroplasts
c. Movement of electrons through membranes
d. Splitting of water molecules

17. During the light-reaction phase of photosynthesis, the addition of the phosphate group with the aid of sunlight is called _____________.
a. photophosphorylation
b. carbohydrate synthesis
c. ribulose formation
d. electron transfer

18. Common shrubs like gumamela and bougainvilleas reproduce asexually by _____________.
a. spore formation
b. fission
c. fertilization
d. vegetative propagation

19. In vascular plants, which type of tissue is responsible for the secondary growth in stems and roots?
a. Cytomembrane
b. Cambium
c. Palisade layer
d. Dermal layer

20. What type of root system is found among grass and other lower plants?
a. Primary
b. Tap
c. Fibrous
d. Branched

21. Which biome grows tropical grassland with scattered individual trees and large herbivores?
a. Tundra
b. Desert
c. Taiga
d. Savanna

22. Which are correctly paired according to their functions?
a. Xylem and cambium
b. Root hair and meristem
c. Lenticel and stomata
d. Phloem and vascular ray

23. The stems/trunks of dicotyledonous plants grow wide in diameter due to the presence of the _____________________.
a. dermal layer
b. sclerenchyma
c. mesophyll
d. cambium layer

24. What are the usual reactions of leaves and roots of plants to conditions in the environment?
1-Phototropism : 2-Thigmotropism : 3-Geotropism : 4-Chemotropism
a. 2 and 4
b. 1 and 3
c. 2 and 3
d. 1 and 4

25. Who experimented on the gas released during photosynthesis and what gas did he find out?
a. Robert Mayer, nitrogen
b. Jan Helmont, oxygen
c. Joseph Priestly, oxygen
d. Jean Senebier, hydrogen

26. By what type of process does a severed portion of a starfish grow into a full starfish?
a. through sex cells
b. bud formation
c. vegetative propagation
d. regeneration

27. What is the common reaction of protozoans to an acidic substance like vinegar?
a. Slight
b. Positive
c. No reaction
d. Negative

28. The diverticulum of the esophagus is for temporary storage of food as in a bird’s ___.
a. crop
b. gizzard
c. cecum
d. palate

29. How can we differentiate an arthropod from annelids?
a. An arthropod has a segmented body; an annelid has non segmented body.
b. Some arthropods have wings; an annelid has legs.
c. An arthropod has exoskeleton; an annelid has endoskeleton.
d. An arthropod has jointed legs; an annelid has none.

30. What do we call the ability of young ducklings to imitate the way their mother duck walks?
a. Disguising
b. Imprinting
c. Mimicking
d. Adapting

31. Birds shed off feathers at least once a year through the process called _________.
a. skinning
b. molting
c. furrowing
d. migrating

32. Which of the following feature of echinoderms like the starfish consists of a system of internal canals extending to the surface?
a. Wall perforations
b. Hydrostatic system
c. Tube feet system
d. Water-vascular system

33. Which animal belongs to the order PRIMATES?
a. Porpoise
b. Ape
c. Whale
d. Bat

34. A mother bird partially digests the food and places an amount into the young’s beak. This process is called __________.
a. external digestion
b. regurgitation
c. feeding dependence
d. redigestion

35. The photoreceptor units found in the compound eyes of insects are called ________.
a. ommatidia
b. visual nerve
c. sclera
d. visual stimulators

36. According to the geologic history of life on earth, during which era did mammals appear?
a. Mesozoic
b. Cenozoic
c. Paleozoic
d. Triassic

37. Which of the following is NOT thought to be an ancestor of humans?
a. Fish
b. Bird
c. Snake
d. Monkey

38. What organ assists the fish to float in their habitat?
a. Air sacs
b. Air bladder
c. Gall bladder
d. Dorsal aerators

39. What chemical controls metamorphosis among insects?
a. Pheromones
b. Estradiol
c. Enzymes
d. Hormones

40. Mammals experience a very minimal change in their body temperature as they move from a warm location to an extremely cold place because they are ___________.
a. cryptophilic
b. poikolothermic
c. thermophilic
d. homeothermic

41. What emergency hormone increases the supply of sugar and oxygen in the blood for more energy?
a. Insulin
b. Pituitrin
c. Thyroxine
d. Adrenalin

42. If bone has osteocytes, skin has _____________.
a. chondrocytes
b. fibrocytes
c. melanocytes
d. osteoblasts

43. What is the recent technology being used now in the surgery of the retina?
a. CT scan
b. Laser
c. Grafts
d. X-ray

44. What may happen with the carbon dioxide concentration in the blood if you hold your breath for half a minute? The carbon dioxide concentrations will ____________.
a. fluctuate
b. decrease
c. remains the same
d. increase

45. Which of the following vitamins is needed for the clotting factor synthesis?
a. E
b. D
c. K
d. B

46. Damaged blood vessels are repaired by __________.
a. thrombocytes
b. erythrocytes
c. leukocytes
d. phagocytes

47. Which muscle disorder accounts for skeletal muscle tissue degeneration that causes a person to experience progressive weakness?
a. Atrophy
b. Dystrophy
c. Cramps
d. Hypertrophy

48. Which of the following vitamins is needed for erythrocytes production?
a. B12
b. D
c. E
d. A

49. When erythrocytes are found in the urine, the condition is diagnosed as ________.
a. hematuria
b. cystitis
c. glomerulonephritis
d. hemophilia

50. Which part of our body serves as a lever, a kind of simple machine?
a. Ligament
b. Spinal Cord
c. Bone
d. Tendon