1. Which term describes the functional unit of a skeletal muscle responsible for muscle contraction?

A. Myofibril
B. Sarcomere
C. Tendon
D. Myoglobin

Correct answer: b

Rationale: The correct answer is B: Sarcomere. A sarcomere is the functional unit of a skeletal muscle responsible for muscle contraction. It is made up of overlapping filaments of actin and myosin proteins. Myofibrils are long, cylindrical structures within muscle cells that contain sarcomeres. Tendons are tough bands of fibrous connective tissue that connect muscles to bones and facilitate movement. Myoglobin is a protein found in muscle cells that stores oxygen for muscle use during exercise. Therefore, the sarcomere is specifically responsible for muscle contraction, making it the correct answer in this question.

2. The process of a fertilized egg attaching itself to the uterine lining is called:

A. Ovulation
B. Implantation
C. Parturition
D. Menstruation

Correct answer: B

Rationale: The correct answer is B: Implantation. Implantation is the process where the fertilized egg, known as a zygote, attaches itself to the uterine lining to begin developing into an embryo. Ovulation is the release of an egg from the ovary, not the attachment process. Parturition refers to the process of giving birth, while menstruation is the shedding of the uterine lining if fertilization does not occur. Therefore, in the context of pregnancy, the process described is specifically referred to as implantation.

3. Which sentence uses the modal verb "should" correctly?

A. You should have studied harder for the exam.
B. I should be going now.
C. She said she should have taken a different route.
D. They should be arriving any minute now.

Correct answer: B

Rationale: Option B conveys an intention or expectation regarding the present or near future.

4. What is the milky-white fluid transported by the lymphatic vessels called?

A. Plasma
B. Blood
C. Chyle
D. Mucus

Correct answer: C

Rationale: The milky-white fluid transported by the lymphatic vessels is called 'Chyle.' Chyle is formed in the small intestine during the absorption of fats. It primarily consists of lymph and emulsified fats. Plasma refers to the liquid component of blood, while blood carries red blood cells, white blood cells, platelets, and plasma. Mucus is a slimy substance produced by mucous membranes. Therefore, option C, 'Chyle,' is the correct answer in this context.

5. Which statement correctly describes the concept of ionization energy?

A. The energy required to remove an electron from an outermost shell.
B. The energy released when an electron bonds with an atom.
C. The total energy possessed by all electrons in an atom.
D. The energy needed to change an atom's nucleus.

Correct answer: A

Rationale: The energy required to remove an electron from an outermost shell. Ionization energy varies depending on the element and electron configuration, indicating its difficulty to lose electrons and influencing its reactivity.

6. The unit for measuring luminous flux, which describes the perceived brightness of a light source by the human eye, is:

A. Candela
B. Lumen
C. Lux
D. Hertz

Correct answer: A

Rationale: The correct answer is B: Lumen. Luminous flux is the measure of the total quantity of visible light emitted by a source per unit time, measured in lumens. The candela (A) is the unit for luminous intensity, lux (C) is the unit for illuminance (luminous flux per unit area), and Hertz (D) is the unit for frequency. Therefore, in this question, the unit for measuring luminous flux is the lumen, as it specifically quantifies the perceived brightness of a light source by the human eye.