Week 15 S2 Bio 109 SI

1. Which part of the eye is responsible for focusing light on the retina?

• Cornea

• • Lens

• Iris

• Pupil

• What is the primary function of the rods in the human eye?

• Color vision

• • Peripheral vision

• Night vision

• • Focusing light

• What does the fovea in the human eye specialize in?

• • Night vision

• Peripheral vision

• Detecting motion

• High-acuity vision

• What is the main role of the optic nerve in vision?

• • Regulating the amount of light entering the eye

• Converting light into neural signals

• • Transmitting visual information to the brain

• • Focusing light on the retina

• Which cells in the retina are responsible for color vision?

• • Cones

• • Ganglion cells

• • Rods

• • Bipolar cells

What are the primary components of a sarcomere in skeletal muscle?

• • Myosin and mitochondria

• • Actin and myosin

• Actin and troponin

• Myosin and tropomyosin

•  During muscle contraction, how do the actin and myosin filaments interact?

• • They disassemble and reassemble

• They remain constant in length but slide past each other

• • They shorten in length

• • They expand in length

•  What is the role of calcium ions in muscle contraction?

• They synthesize new actin and myosin filaments

• • They break down ATP to provide energy

• • They form cross-bridges between actin and myosin

• • They bind to troponin, changing its shape and exposing myosin-binding sites on actin

• What is the primary energy source for muscle contraction?

• • Glucose

• Oxygen

• • ATP

• Fatty acids

In the sliding filament model of muscle contraction, what role does ATP play?

• ATP changes the shape of the muscle fiber for contraction

• ATP is broken down to provide energy for the cross-bridge

• •  ATP shortens the muscle fibers for contraction

• ATP directly stimulates the motor neurons