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All Free Biology MCQs with Answers

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19,844 questions · page 835 of 993

16681. What is the joint between atlas and axis is called?

  • A. Hinge joint
  • B. Pivot joint
  • C. Gliding joint
  • D. Saddle joint

Explanation: The atlas (C1) and axis (C2) form a pivot joint, allowing rotation of the head.

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Correct answer: Pivot joint

16682. The contractile protein of a muscle is?

  • A. Actin
  • B. Myosin
  • C. Tubulin
  • D. Tropomyosin

Explanation: Myosin interacts with actin filaments for contraction and has ATPase activity.

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Correct answer: Myosin

16683. The functional unit of the contractile system in striated muscle is?

  • A. Sarcomere
  • B. Z line
  • C. Cross bridges
  • D. Myofibril

Explanation: The sarcomere is the functional unit of striated muscle fibers, defined as the segment between two Z lines.

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Correct answer: Sarcomere

16684. Which joint type is found between skull bones ?

  • A. Synovial joint
  • B. Cartilaginous joint
  • C. Fibrous joint
  • D. Pivot joint

Explanation: The skull bones are connected by immovable fibrous joints (sutures).

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Correct answer: Fibrous joint

16685. The sarcolemma of muscle fibers folds inwards and forms a system of tubes which run through the sarcoplasm called:

  • A. Myofilaments
  • B. Z-lines
  • C. Sarcoplasmic reticulum
  • D. Transverse tubules

Explanation: Transverse tubules, also known as T-tubules, are formed by the invagination of the sarcolemma into the sarcoplasm.

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Correct answer: Transverse tubules

16686. The microtubules in the cytoskeleton are made up of the protein:

  • A. Tropomyosin
  • B. Myosin
  • C. Tubulin
  • D. Actin

Explanation: Microtubules are cylindrical structures in the cytoskeleton made of tubulin protein, which assembles into long, hollow tubes.

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Correct answer: Tubulin

16687. Which of the following joint is also known as an ellipsoidal joint?

  • A. Saddle joint
  • B. Condyloid joint
  • C. Ball and socket joint
  • D. None of these

Explanation: An ellipsoidal joint is also known as a condyloid joint. This type of joint is a synovial joint that allows for movement in two planes…

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Correct answer: Condyloid joint

16688. Joints found at the vertebrae are:

  • A. Gliding joints
  • B. Sliding joints
  • C. Partially moveable joints
  • D. Fixed joints
  • E. Pivot joints

Explanation: Gliding joints are present between vertebrates.

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Correct answer: Gliding joints

16689. The first vertebrae of the cervical region of the vertebral column is known as:

  • A. Atlas
  • B. Sacral
  • C. Thoracic
  • D. Axis

Explanation: The first vertebra of the cervical region is known as the atlas. It supports the skull and allows for nodding movements of the head.

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Correct answer: Atlas

16690. Find the Error.One of the things(A) that really makes(B) me angry is (C)people who don't answer(D) emails.

  • A. One of the things
  • B. That really make
  • C. Is
  • D. Don't answer

Explanation: The error lies in the phrase 'that really makes.' Here, 'that' refers to 'things,' which is plural, so the verb should be 'make' instead…

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Correct answer: That really make

16691. Spot the error.At the car park entrance turn the right along the road to return to the junction by the bridge over the river.

  • A. The car park
  • B. The right
  • C. The junction
  • D. The river

Explanation: The correct answer is B. The sentence should read: "At the car park entrance, turn right along the road to return to the junction by the…

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Correct answer: The right

16692. Spot the error. I cannot say anything about me going to Karachi as the flights are getting delayed.

  • A. cannot
  • B. me
  • C. as
  • D. delayed

Explanation: This is the error. In formal English, when talking about oneself about actions (like going somewhere), "my" is the correct possessive…

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Correct answer: me

16693. Find the error of punctuation"These were good days,Jess! That's why I remember this mountain."

  • A. Days
  • B. Jess
  • C. That's
  • D. Mountain

Explanation: The correct answer is B) Jess. The error in punctuation lies in the lack of spacing after the comma following 'days,' which should be…

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Correct answer: Jess

16694. Select the most suitable synonym for the given word:BASHFUL

  • A. Timid
  • B. Susceptible
  • C. Bold
  • D. Invulnerable

Explanation: Bashful means to be shy and unwilling to attract attention, similarly timid also means to be shy.

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Correct answer: Timid

16695. Directions: In the following question, a number sequence is given with one term missing. Choose the correct term that will continue the same pattern and replace the question mark in the given sequence.71,25,83,37,95,49,?

  • A. A: 61
  • B. B: 107
  • C. C: 59
  • D. D: 105

Explanation: The given sequence is: 71, 25, 83, 37, 95, 49, ?Separate the sequence into two alternating patterns:1st, 3rd, 5th terms: 71, 83, 952nd…

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Correct answer: B: 107

16696. In this question, a statement is given followed by two courses of action numbered I and II. It is required to grasp the statement, analyze the problem or policy it mentions and then decide which of the courses of action logically follow / most appropriate.Statement:The teenager was arrested by the police for taking drugs.Courses of action:I) The teenager should be meted with corporal punishment by the police.II) The teenager should be sent to a drug rehabilitation centre.

  • A. If only I follows
  • B. If only II follows
  • C. If either I or II follows
  • D. If neither I nor II follows
  • E. If both I and II follow

Explanation: The correct answer is Option B: If only II follows. Sending the teenager to a drug rehabilitation center (Course of Action II) is the most…

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Correct answer: If only II follows

16697. The animal that is CORRECTLY categorised on the basis of the production of metabolic heatby its body is

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: Sparrows are endothermic, meaning they generate their own body heat and maintain a relatively constant internal body temperature…

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Correct answer: C

16698. What type of heat exchange is promoted by vasodilation

  • A. Convection
  • B. Conduction
  • C. Evaporation
  • D. Radiation

Explanation: Vasodilation brings more blood and heat to the body surface, facilitating radiation and evaporative heat loss, which helps to cool the…

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Correct answer: Radiation

16699. Which of the following would increase the rate of heat exchange between an animal and its environment?

  • A. Feather or fur
  • B. Vasoconstriction
  • C. Wind blowing across the body surface
  • D. Counter current heat exchange

Explanation: Wind blowing across the body surface can increase the rate of heat exchange.

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Correct answer: Wind blowing across the body surface

16700. When the outer air temperature is higher than body temperature, which of the following combination of control mechanisms is the most likely to occur?

  • A. A
  • B. B
  • C. C
  • D. D

Explanation: When the outer air temperature is higher than body temperature, the body's thermoregulatory response shifts to cooling mechanisms such as…

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Correct answer: D
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