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The postulates of the cell theory was proposed by

A unicellular animal P having no fixed shape ingests a food particle by forming temporary finger-like projections Q. The food particle is engulfed with a little surrounding water to form a temporary stomach R inside it. The chemicals S from surrounding cytoplasm enter into R and break down food into small and soluble molecules by chemical reactions. The digested food is absorbed directly into the cytoplasm by the process T. The undigested food is thrown out of the body by the rupture of a cell organelle U in a process called V.
(a) Name the unicellular animal P.
(b) What are (i) Q and (ii) R?
(c) Name (i) chemical S, and (ii) process T.
(d) Name (i) organelle U, and (ii) process V.

In a neuron, the conversion of electrical signal to a chemical signal occurs at/in :

(a) dendrite end

(b) cell body

(c) axon end

(d) myelin sheath

The human body contains a large number of cells A which are very long and branched, and look like electric wires. The longest branch of this cell is B whereas there are many small branches C. Any two A cells do not join to one another completely in the human body. There is a microscopic gap D between every pair of adjacent A cells through which electric impulses can pass by the release of a chemical substance.

(a) What are cells A ?

(b) What is the name of (i) branch B, and (ii) branches C ?

(c) What is the microscopic gap D is known as ?

(d) What is the function of cells like A in the human body ?

(e) The cells A are of three types. Name the three types.

Sertoli cells are very much essential during spermatogenesis. Why?

What is meant by the term 'double circulation' of blood in mammals? What is diastole?

Which of the following is a function of tRNA?

The process by which variations enabling better survival are inherited, so that, an organism can reproduce and leave a greater number of offsprings is called:

A dialysis machine contains long tubes coiled in a tank containing dialysing solution :
(i) Of what substance are the tubes made ?
(ii) What does the dialysing solution contain ?
(iii) Name the main waste product that passes into the dialysing solution.

The hormones secreted by anterior lobe of pituitary to regulate gonads is _.

Loading of sucrose into sieve tube cells is by (i)_______ and the unloading of sucrose from the sieve tube cells is by (ii)________.

We do not clean ponds lakes but an aquarium needs to be cleaned regularly. Explain.

A. However, Owen Paterson, the environment secretary, has signalled he is opposed to a ban and appears to support the position of the insecticide manufacturers and farming lobby who argue that banning such products would harm food production.
B. A recent poll found that 71% of Britons would support such a ban.
C. The move would be warmly welcomed by environmentalists who have long argued that "neonics" should be banned.
D. European officials are set to vote on a proposal that would see a group of insecticides known as neonicotinoids, which have been implicated in the decline of bees, largely outlawed across the continent.
E. The debate raises the wider question of how valuable bees, and other pollinators, are to our agricultural economy.

Muscles which contract and relax upon the will of an individual is

Name two animals which breathe through gills.

Water will be absorbed by the root hairs when:

What does the figure given below represent?

1. Explain the process of nutrition in humans in 100 words.

2. Write all the glands and their secretions involved in digestion of food in human.

3. Which nutrient is converted in which compound?

Question 2 (a)
Mark (T) if the statement is true and (F) if it is false:
(a) Digestion of starch starts in the stomach.

How do we detect the smell of an incense stick?

Name the accessory glands in humans for digestion. Explain their function.

Which of the following statement is incorrect?

Difference between 70S and 80S type ribosome?

Which of the following is/are digestive gland(s)?

Which of these is not part of an animal cell?

Why aquatic plants don't have stomata?

Which of the following stimulates other white blood cells for defense activity?

The organs P and Q of two animals have different structures but similar functions. On the other hand, the two organs R and S of two other animals have the same basic structure but different functions.
(a) What are the organs like P and Q known as
(b) Name the organs like P and Q. Also name the animals which have such organs.
(c) What are the organs like R and S called?
(d) Name the organs like R and S. Also name the animals which have such organs.

The red-RR is crossed with white-rr. All the offspring are pink-Rr. This indicates the R gene is_________.

Which of these is a hormonal method of contraception?

Which property of camel’s skin helps in conservation of water?

Select the group which shares the maximum number of common characters :

(a) two individuals of a species (b) two species of a genus

(c) two genera of a family (d) two genera of two families

Name the organelle of plant cells in which photosynthesis occurs.

Assertion: The phloem sap moves towards the sink.

Reason: The process of loading at the source produces a hypotonic condition in the phloem.

Excess of which of the following hormones causes Cushing's syndrome?

There is a pair of bean-shaped organs Pin the human body towards the back, just above the waist. A waste product Q formed by the decomposition of unused proteins in the liver is brought into organ I' through blood by an artery R. The numerous tiny filters S present in organ P clean the dirty blood by removing the waste product Q. The clean blood goes into circulation through a vein T. The waste substance Q, other waste salts, and excess water form a yellowish liquid U which goes from organ P into a bag-like structure V through two tubes W. This liquid is then thrown out of the body through a tube X.
(a) What is (i) organ P, and (ii) waste substance Q?
(b) Name (i) artery R, and (ii) vein T.
(c) What are tiny filters S known as?
(d) Name (i) liquid U (ii) structure V (iii) tubes W, and (iv) tube X.

Why arteries have thick, elastic walls, while veins have thin walls?

Given below is the partially incomplete scheme of the components of peripheral nervous system. Fill up the blanks numbered (1) -(8) :

Name the various types of asexual reproduction.

Which of the following fuel is the least polluting?