Life Processes: 36 MCQs with answers

Carbon dioxide

Carbon dioxide is one of the raw materials for photosynthesis, along with water and sunlight.

Chloroplast

Chloroplasts contain chlorophyll, which captures light energy for photosynthesis.

Alveoli

Alveoli are tiny air sacs in the lungs where exchange of oxygen and carbon dioxide occurs.

Nephron

Nephron is the basic structural and functional unit of the kidney.

Excretion

Excretion is the biological process of removing metabolic wastes from the body.

Aorta

Aorta is the main and largest artery that carries oxygenated blood from the left ventricle to the body.

Trachea

Trachea is part of the respiratory system, not the digestive system.

True

Plants perform photosynthesis to make food and respiration to release energy from food.

True

The human heart has four chambers: two atria and two ventricles.

To break down food

The primary function of the digestive system is to break down food into nutrients that the body can use.

Nutrients

The circulatory system primarily transports nutrients absorbed from food to cells throughout the body.

To produce energy

The main purpose of respiration is to produce energy by converting glucose and oxygen into carbon dioxide and water.

Kidney

The kidneys are primarily responsible for excreting waste products from the blood and regulating fluid balance.

Photosynthesis

Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose.

Carbon dioxide

Carbon dioxide is a byproduct of aerobic respiration, which occurs when glucose is broken down in the presence of oxygen.

To transport water and nutrients

The vascular system in plants is responsible for transporting water, nutrients, and sugars throughout the plant.

Excretion

Excretion is the process of removing waste products from the body, ensuring that harmful substances do not accumulate.

Lungs

The lungs are a key component of the human respiratory system, facilitating the exchange of gases.

Carbohydrates

Carbohydrates are the primary source of energy for the body, as they can be quickly broken down into glucose.

Cuscuta

Cuscuta (amarbel) is a parasitic plant that derives nutrition from the host plant.

Nostrils → Trachea → Bronchi → Alveoli

Air enters through nostrils, passes through trachea, then bronchi, and finally reaches alveoli.

Pulmonary vein

Pulmonary vein carries oxygenated blood from lungs to the left atrium of the heart.

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$

Aerobic respiration breaks down glucose in the presence of oxygen to release carbon dioxide, water, and energy.

Lactic acid

In human muscle cells, anaerobic respiration produces lactic acid, which causes cramps.

Upward movement of water and minerals

Transpiration creates a suction pull that helps in the upward movement of water and minerals from roots to leaves.

Salivary amylase

Salivary amylase (ptyalin) digests starch into simpler sugars like maltose.

Aerobic respiration

Aerobic respiration is a process that occurs in both plants and animals to convert glucose into energy using oxygen.

They are disc-shaped to increase surface area for oxygen absorption.

The disc shape of red blood cells increases their surface area, allowing for more efficient oxygen absorption and transport.

Kidney

The kidneys filter blood to remove waste products and excess substances, playing a crucial role in excretion.

Aerobic respiration produces carbon dioxide and water, while anaerobic respiration produces lactic acid or ethanol.

Aerobic respiration produces carbon dioxide and water as byproducts, while anaerobic respiration can produce lactic acid or ethanol, depending on the organism.

Transporting food from leaves to other parts of the plant.

The phloem is responsible for transporting the products of photosynthesis (food) from the leaves to other parts of the plant.

Proteins

Proteins are crucial for the synthesis of enzymes and hormones, which are vital for various biochemical processes in the body.

The loss of water vapor from aerial parts of the plant.

Transpiration is the process where water vapor is lost from the aerial parts of the plant, primarily through stomata in the leaves.

Respiratory system

The respiratory system is responsible for the exchange of gases, specifically oxygen and carbon dioxide, in the lungs.

It transports nutrients from the digestive system to cells throughout the body.

The circulatory system transports nutrients absorbed from the digestive system to cells throughout the body for use.

Anaerobic respiration

Anaerobic respiration is the process that converts glucose into energy in the absence of oxygen, often resulting in byproducts like lactic acid.