Describe double circulation in human beings. Why is it necessary?
The double circulatory system of blood flow refers to the separate systems of pulmonary circulation and the systemic circulation.
The adult human heart consists of two separated pumps, the right side with the right atrium and ventricle which pumps deoxygenated blood into the pulmonary circulation.
The oxygenated blood re-enters the left side of the heart through the pulmonary vein into the left atrium and passes to the left ventricle where it is pumped to the rest of the body. This part of the circulation is called as systemic circulation. This type of circulation is called double circulation. The advantage of a double circulatory system is that blood can be pumped to the rest of the body at a higher pressure.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
State the three common features of all the respiratory organs like skin, gills and lungs.
(a) What is common for Cuscuta, ticks and leeches ?
(b) Name the substances on which the following enzymes act in the human digestive system :
(i) Trypsin (ii) Amylase (iii) Pepsin (iv) Lipase
(c) Why does absorption of digested food occur mainly in the small intestine ?
Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.
(a) What is meant by breathing? What happens to the rate of breathing during vigorous exercise and why?
(b) Define translocation with respect to transport in plants. Why is it essential for plants? Where in plants are the following synthesised?
(i) Sugar (iii) Hormone
Name the final product/products obtained in the anaerobic respiration, if it takes place :
(a) in a plant (like yeast).
(b) in an animal tissue (like muscles).
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
Name the process by which plant parts like roots, stems, and leaves get oxygen required for respiration.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
Draw a neat diagram of excretory system of human beings and label on it:
(i) Left kidney (ii) Urinary bladder
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
(a) List the three events that occur during the process of photosynthesis.
Explain the role of stomata in this process.
(b) Describe an experiment to show that "sunlight is essential for photosynthesis."
Arrange the following processes involved in the nutrition in animals in the correct order (in which they take place):
Assimilation, Egestion, Ingestion, Absorption, Digestion
What are the differences between aerobic and anaerobic respiration ? Name some organisms that use anaerobic mode of respiration.
(a)Explain how does the exchange of gases occur in plants across the surface of stems, roots and leaves.
(b) How are water and minerals transported in plants ?
In human alimentary canal, name the site of complete digestion of various components of food. Explain the process of digestion.
List the three kinds of blood vessels of human circulatory system and write ¦ their functions in tabular form.
(a) Draw a diagram to show open stomatal pore and label on it:
(i) guard cells
(ii) chloroplast
(b) State two functions of stomata.
(c) How do guard cells regulate the opening and closing of stomatal pore?
Draw a neat diagram of excretory system of human beings and label the following:
(i) Kidney
(ii) Ureter
(iii) Urinary Bladder
(iv) Urethra
(a) Draw a sectional view of the human heart and label on it – Aorta, Right ventricle and Pulmonary veins.
(b) State the functions of the following components of transport system:
(i) Blood (ii) Lymph
Name the green dot like structures in some cells observed by a student when a leaf peel was viewed under a microscope. What is this green colour due to?
Name the component of blood that helps in the formation of blood clot in the event of a cut.
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?