Life process Important Questions

👉Answers to these questions👈
Q1. What are nutrients?

Q2. What is autotrophic nutrition?

Q3. What is heterotrophic nutrition?

Q4. What are the raw materials required for photosynthesis?

Q5. From where do the green plants get carbon dioxide? 

Q6. Why are minerals essential in photosynthesis?

Q7. What is holozoic nutrition?

Q8. What are saprotrophs?

Q9. Name the different types of heterotrophic nutrition?

Q10. What would be the consequences of deficiency of haemoglobin in blood.

SHORT ANSWER QUESTIONS

Q1. What is the importance of nutrients?

Q2. Give account of the reaction of the photosynthetic reaction?

Q3. Write short notes on absorption?

Q4. What is the function of large intestine in the human digestive system?

Q5. How is food digested in amoeba?

Transportation

22-May-2020

Two types of blood vessels are arteries and veins which are connected to the heart for transporting blood.

• Arteries –
• Carry blood rich in oxygen from the heart to all the cells of the body.
• The pressure exerted by the arteries while blood leave heart is rapid and thus wall walls of arteries are thick.
• The arteries divide in to extremely small thin branches on reaching the tissues. These small branches are called as capillaries.
  
• Capillaries have walls and are one-cell thick through which the exchange of materials between the blood and surrounding cells take place across this thin wall.
  

Veins

• Veins carry blood rich in carbon di oxide from all the cells of the body to the heart.
• The pressure exerted by the walls of the veins is less and have thin walls.
• Valves present in the veins ensure that the blood flows only towards the heart.

HUMAN CIRCULATORY SYSTEM

* The human circulatory system consists of a network of arteries, veins, and capillaries, with the heart pumping blood through it.

* Its primary role is to provide essential nutrients, minerals, and hormones to various parts of the body. * Alternatively, the circulatory system is also responsible for collecting metabolic waste and toxins from the cells and tissues to be purified or expelled from the body.

FEATURES OF CIRCULATORY SYSTEM

The crucial features of human circulatory are as follows:

• The human circulatory system consists of blood, heart, blood vessels, and lymph.
• The human circulatory system circulates blood through two loops (double circulation) – One for oxygenated blood, another for deoxygenated blood.
• The human heart consists of four chambers – two ventricles and two auricles.
• The human circulatory system possesses a body-wide network of blood vessels. These comprise of arteries, veins, and capillaries.
• The primary function of blood vessels is to transport oxygenated blood and nutrients to all parts of the body. It is also tasked with collecting metabolic wastes to be expelled from the body.
• Most circulatory system diagrams do not visually represent is its sheer length. Theoretically, if the veins, arteries, and capillaries of a human were laid out, end to end, it would span a total distance of 1,00,000 kilometres (or roughly eight times the diameter of the Earth).

23-May-2020

TRANSPORTATION IN PLANTS

1. Transportation is a vital process in plants.

This process involves the transportation of water and necessary nutrients to all parts of the plant for its survival.

2. Food and water transportation takes place separately in plants.

3. Xylem transports water and phloem transports food.

PHLOEM

1.  The phloem is responsible for translocation of nutrients and sugar like carbohydrates, produced by the leaves to areas of the plant that are metabolically active.

2. Sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells are the components of this tissue.

3. The flow of material through phloem is bidirectional.

EXCRETION

Life Process QUESTIONS

EXCRETION

Excretion is a biological process by which an organism get rid of excess or toxic waste products of metabolism.

Excretion removes unwanted by-products of metabolism,toxic chemical substances, regulate the ionic concentration of body fluids,regulates water content of body,regulate pH of body fluids.

EXCRETION IN HUMANS

HUMAN EXCRETORY SYSTEM

It consists of a pair of Kidneys, a pair of ureters, Urinary bladder and Urethra.
The Kidneys are located in the abdominal cavity, situated below the level of last thoracic and third lumbar vertebra close to the dorsal inner wall of abdominal cavity.
Each kidney is been shaped reddish brown.
The right kidney is lower and smaller than left kidney because the liver takes up much space on the right side.
From each kidney, one ureter arises, and the two Ureters open obliquely into the Urinary bladder, which is a hollow, muscular sac-like structure that stores urine.
Urethra is the membranous tube that arises from the neck of the bladder and conduct the urine to the exterior.

Internally a kidney is made of numerous microscopic excretory units called nephrons.

The function of kidney is filtration of blood to excrete the waste products of metabolism. The kidney filters about 190 litres of blood to produce 0.9-21 of urine daily.

STRUCTURE OF NEPHRONS

Each nephron has cup shaped upper end called Bowman's Capsule.It contain bundles of blood capillaries called glomerulus. The Bowman's capsule and glomerulus together form globular body called renal corpuscle.

The blood in the capillaries of glomerulus come from aorta by renal arteries and after passing through glomerulus it returns to the posterior vena cava via renal vein.The blood entering into glomerulus carries waste material which are filtered out in the Bowman's capsule.

Filtration is possible because walls of glomerular capillaries and Bowman's capsule are very thin and selectively permeable.

PROCESS OF FILTRATION 

• A pair of kidneys, a pair of ureters, a urinary bladder and a urethra constitutes the human excretory system.
• Kidneys are present on either side of the backbone in the abdomen.
• Kidneys produce urine and urine from kidney passes through the ureters into the urinary bladder and remains stored their until it is released through the urethra.

Fig. Human excretory system  

• Urine is produced to filter out waste products from the blood.
• Nephrons are basic structural and functional unit of kidney.
• Cluster of thin walled blood capillaries called glomerulus in the nephron filtrate the urine and each cluster is associated with cup shaped end of a tube called Bowman’s capsule.

Fig. Nephron  

• Substances like glucose, amino acids, salts and a major amount of water is selectively reabsorbed from the initial filtrate as the urine flows along the tube.
• Reabsorption depends on the amount of excess water in the body and dissolved waste to be excreted.
• The urine from kidney enters the long tube called ureter.
• Ureter connects the kidney with the urinary bladder and urine from the kidney is passed to urinary bladder and stored in the bladder.
• When the pressure in the expanded bladder leads to the urge to urinate, the urine is passed out through urethra.

EXCRETION IN PLANTS

Excretion is the removal of waste from the body. Plants also produce waste products but very slowly and in very small amounts. They do not have any special organ for the removal of their waste product.

The waste products of a plant are carbon dioxide, water vapour and oxygen. While carbon dioxide and water vapour are waste products of respiration, oxygen is a waste product of photosynthesis. These waste products are removed through stomata in leaves and lenticels in stems and are released into the air.

Some of the waste products are stored in the leaves, bark and fruits of a plant or a tree. Trees get rid of them when dead leaves bark and ripe fruits fall off from them. Some plants store waste in their fruits in the form of solid bodies called raphides. For example, fruit yam has needle-shaped raphides on its surface. Plants also secrete waste in the form of gum and resins from their stem and branches.

Therefore, various methods used by plants to get rid of their waste products are:

• Gaseous waste through stomata and lenticels.
• Stored solid and liquid waste by shedding leaves, peeling of bark and falling of fruits.
• By secreting waste in the form of gum and resins.
• Excrete waste into the soil around them.