(a) Name the type of blood (oxygenated / deoxygenated) transported by each of the following mentioning the path (i.e. from one organ (which place) to another (which place)). (i) Vena cava (ii) Pulmonary artery OR (b) With the help of a schematic flow chart, show the breakdown of glucose in a cell to provide energy - (i) in the presence of oxygen (ii) in lack of oxygen

Part (a)

(i) Vena cava:

• Type of blood: Deoxygenated blood.
• Path: Transports deoxygenated blood from various tissues and organs of the body to the right atrium of the heart.

(ii) Pulmonary artery:

• Type of blood: Deoxygenated blood.
• Path: Transports deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation.

---

OR

Part (b)

In a cell, the first step of glucose breakdown occurs in the cytoplasm, where glucose (a 6-carbon molecule) is broken down into pyruvate (a 3-carbon molecule) along with the release of energy:

$$\text{Glucose (6-carbon compound)} \xrightarrow{\text{In cytoplasm}} \text{Pyruvate (3-carbon compound) + Energy}$$

From pyruvate, the breakdown proceeds via different pathways depending on oxygen availability:

(i) In the presence of oxygen (Aerobic Respiration in Mitochondria):

$$\text{Pyruvate} \xrightarrow{\text{Oxygen (Mitochondria)}} 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy (ATP)}$$

(ii) In lack of oxygen (Anaerobic Respiration in Human Muscle Cells):

$$\text{Pyruvate} \xrightarrow{\text{Lack of oxygen (Muscle cells)}} \text{Lactic acid (3-carbon compound) + Energy}$$