Unit 14: Transport

What is Transport?

“Transport” is a fundamental chapter that explores the mechanisms by which substances are moved within and between cells, tissues, and organs in living organisms. This unit introduces students to the various modes of transport, including passive and active mechanisms, and their roles in maintaining homeostasis and supporting physiological functions. The chapter covers key processes such as diffusion, osmosis, and active transport, as well as the structure and function of transport systems in different organisms. Understanding transport is crucial for grasping how materials are exchanged and regulated within biological systems.

Key Topics in Transport:

• Basic Transport Mechanisms: Examining the principles of diffusion and osmosis, and how these passive transport processes facilitate the movement of substances across cell membranes.
• Active Transport: Understanding the role of active transport in moving molecules against their concentration gradients using energy, including processes such as the sodium-potassium pump.
• Transport Systems in Plants: Learning about the transport of water, nutrients, and sugars in plants, including the functions of xylem and phloem.
• Transport Systems in Animals: Investigating the circulatory systems in animals, including the roles of blood, heart, and blood vessels in nutrient and gas transport.
• Regulation and Efficiency: Exploring how transport processes are regulated and optimized to meet the needs of cells and organisms, including responses to environmental changes.

Benefits of Studying Transport:

• Understanding Cellular Processes: Provides insight into how substances are moved and regulated within cells and organisms, which is essential for understanding cellular and physiological functions.
• Applications in Medicine: Knowledge of transport mechanisms is crucial for understanding diseases related to nutrient and ion imbalances, such as cystic fibrosis and diabetes.
• Insight into Plant and Animal Systems: Enhances understanding of how different organisms manage the transport of essential substances, including the roles of specialized tissues and organs.
• Foundation for Advanced Studies: Establishes a base for further studies in physiology, cell biology, and environmental science.

This chapter is essential for understanding how materials are transported within biological systems and how this process supports overall health and function. Mastering the concepts of transport provides students with a solid foundation for further studies in biology and related fields.

1. Which of the following is not true of guard cells?

a. They are present in epidermis of leaf
b. They are connected with plasmodesmata with other epidermal cells
c. They contain chloroplast
d. they are kidney shaped

2. The casparian strips are present in

a. cortex cells of roots
b. endodermis cells of roots
c. cells of pericycle
d. cells of phloem

3. Lymph most closely resemble with

a. blood
b. plasma
c. interstitial fluid
d. urine

4. Hydathodes are associated with

a. transpiration
b.guttation
c. conduction
d. none

5. According to pressure flow theory, which of the following serves as sink

a. leaves
b. stem
c. roots
d. none

6. Which of the following is true about mammals

a. They have right aortic arch only
b. They have left aortic arch only
c. They have rightand left aortic arch only
d. They donot have aortic arch

7. The process that most likely enables a root hair cell to absorb minerals by active transport and enables a muscle cell to contract is

a. circulation
b. excretion
c. respiration
d. assimilation

8. Which of the following processes cause substances to move across membranes without the expenditure of cellular energy

a. endocytosis
b. active transport
c. diffusion
d. none

9. Cardiac muscle can be distinguished from other muscle fibres because cardiac muscle

a. contain only actin
b. voluntary in action
c. lacks regular arrangment of sarcomeres
d. has interrelated discs