Gas Exchange and Hemoglobin Function

The video covers gas exchange in organisms, focusing on adaptations in humans and plants. It explains the mechanics of ventilation, different lung volumes, and the role of hemoglobin in oxygen transport. The video also discusses plant adaptations for gas exchange and transpiration. It concludes with a review and questions to reinforce learning.

Why do gas exchange surfaces need to be moist?

• To increase surface area

• To allow gases to dissolve

• To maintain temperature

• To prevent dehydration

What maintains the concentration gradient necessary for gas exchange in the lungs?

• Constant blood flow

• High humidity

• Thick alveolar walls

• Low body temperature

During inhalation, which muscles contract to allow air to enter the lungs?

• Neck muscles

• Internal intercostal muscles

• Diaphragm and external intercostal muscles

• Abdominal muscles

What is the primary function of guard cells in plant leaves?

• To transport water

• To store nutrients

• To absorb sunlight

• To open and close stomata

How does temperature affect the rate of transpiration in plants?

• Higher temperature decreases transpiration

• Higher temperature increases transpiration

• Temperature has no effect

• Lower temperature increases transpiration

Which of the following is NOT a factor affecting transpiration rate?

• Soil type

• Temperature

• Wind speed

• Humidity

What structural feature of hemoglobin allows it to bind oxygen cooperatively?

• Its quaternary structure

• Its ability to bind carbon dioxide

• Its heme groups

• Its single subunit

Why does fetal hemoglobin have a higher affinity for oxygen than adult hemoglobin?

• It is found in higher concentrations

• It needs to extract oxygen from maternal blood

• It has more heme groups

• It binds carbon dioxide more effectively

What effect does carbon dioxide have on hemoglobin's affinity for oxygen?

• No effect

• Decreases affinity

• Increases affinity

• Doubles affinity

What shape is the hemoglobin dissociation curve and why?

• Linear due to constant binding

• S-shaped due to cooperative binding

• Exponential due to rapid binding

• Flat due to no binding