Tag: biology

Questions Related to biology

Moll's half - leaf experiment proves that _________ is essential for photosynthesis to take place. 
biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. chlorophyll

  2. $CO _{2} $

  3. light

  4. $H _{2} O $

Show answer
Correct Option: B
Explanation:

In Moll's half leaf experiment a destarched plant is used.Half part of one of the leaves from the plant is inserted into a corked bottle containing either KOH solution or KOH palletes. The plant is then placed in sunlight for a few hours. The leaf is then tested for starch with iodine solution. Part of the leaf that was inserted in the bottle does not turn blue or test positive for starch. This is because $CO _2$ present in the bottle was aborbed by KOH and the bottle was corked to prevent any entry of air.Proving that $CO _2$ is essential for photosynthesis.

So, the correct answer is $CO _2$


Choose the correct answer from the alternatives given.
Molls experiment demonstrates the necessity of which of the following in photosynthesis

biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. water

  2. oxygen

  3. carbon dioxide

  4. chlorophyll

Show answer
Correct Option: C
Explanation:

Molls experiment evidently shows that plants do not form starch when carbon dioxide is not at their disposal, all the carbon dioxide contained in the bottle having been absorbed by the caustic potash solution.

Thus, the correct answer is 'Carbon dioxide.'

Photochemical phase does not include 
biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. light absorption

  2. water splitting and $ O _{2}$ release

  3. ATP and NADPH formation

  4. $CO _{2}$ fixation

Show answer
Correct Option: D
Explanation:

The complete process of photosynthesis is studied under two phases - photochemical phase and biosynthetic phase. Photochemical phase involves absorption of light energy, photolysis of water with the release of $O _{2}$ and production of assimilatory power (i.e. ATP + NADPH).$CO _{2} $ fixation occurs during biosynthetic phase of photosynthesis. 

In the experiment " To show that $CO _{2}$ is given out during respiration" the water level in the bent tube rise after sometime because

biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. germinating seeds consume all the $O _{2}$ and $CO _{2}$ in the flask.

  2. the germinating seeds consume $O _{2}$ and give out $CO _{2}$ which is absorbed by a chemical filled in the small test tube.

  3. $CO _{2}$ is given out by the germinating seeds.

  4. seeds need water for germination and grow.

Show answer
Correct Option: B

The process of conversion of complex food substance to simple absorbable forms is called:

biology excretion - the wastage disposing system excretion in other organisms other excretory organ role of other organs in excretion

  1. Excretion

  2. Respiration

  3. Digestion

  4. Circulation

Show answer
Correct Option: A

Organisms that excrete amino acid is

biology excretion - the wastage disposing system excretion in other organisms other excretory organ role of other organs in excretion

  1. Aminotelic

  2. Ammonotelic

  3. Ureotelic

  4. Uricotelic

Show answer
Correct Option: A
Explanation:

Certain invertebrates like some molluscs (Unio, Limnaea, etc.) and some echinoderms (e.g., Asterias) excrete excess amino acids as such. These animals are called aminotelic and their mode of excretion is called aminotelism.

So, the correct option is 'Aminotelic'.

Match the following w.r.t Platyhelminthes.

A) Flame Cells I. Anchorage
B) Hooks and Suckers II. Absorption
C) Regeneration III. Osmo regulation
D) Body surface IV. Planaria
biology excretion to maintain homeostasis excretion in other organisms other excretory organ role of other organs in excretion

  1. $A - II, B - IV, C - I, D - III$

  2. $A - III, B - I, C - IV, D - II$

  3. $A - III, B - II, C - III, D - I$

  4. $A - IV, B - II, C - I, D - III$

Show answer
Correct Option: B
Explanation:

A flame cell is a specialized excretory cell found in the platyhelminthes like planaria. They  function like a kidney, removing waste materials by the process of osmoregulation.

Hooks and suckers are specialized structures in parasites of the platyhelminthes like tapeworm. It helps in attachment and anchoring to the host organisms.
Planaria can be cut into pieces, and each piece can regenerate into a complete organism. Cells at the location of the wound site proliferate to form a blastema that will differentiate into new tissues and regenerate the missing parts of the piece of the cut planaria.
Increased body surface helps in more absorption in platyhelminthes.
 So the correct answer should be option B "A-III, B-I, C-IV, D -II"

Match the excretory organs listed under column I with the animals given under column II and select the correct option.

Column I(Excretory organs) Column II(Animals)
A. Nephridia (i) Hydra
B. Malpighian tubules (ii) Leech
C. Protonephridia (iii) Shark
D. Kidneys (iv) Roundworms
(v) Cockroach
biology excretion to maintain homeostasis excretion in other organisms other excretory organ role of other organs in excretion

  1. A-(ii), B-(v), C-(iv), D-(iii)

  2. A-(iv), B-(ii), C-(i), D-(v)

  3. A-(v), B-(ii), C-(iv), D-(iii)

  4. A-(ii), B-(iv), C-(v), D-(i)

Show answer
Correct Option: A
Explanation:

(A) Nephridia - Leech

(B) Malpighian tubules - Cockroach
(C) Protonephridia - Roundworms
(D) Kidneys - Shark
So, the correct answer is (a).

Which one of the following doesnt have a aminotelic excretory system?

biology excretion to maintain homeostasis excretion in other organisms other excretory organ role of other organs in excretion

  1. Asterias

  2. Unio

  3. Limnaea

  4. Oniscus 

Show answer
Correct Option: D
Explanation:

Organisms which excretes amino acids are called aminotelic. Organisms like Asterias, Uni, Limnaea etc have an aminotelic excretory system. Oniscus is a land crustacean which excretes uric acid and falls into uricotelic category.

Since Oniscus is the odd one, the correct option is 'D'.

Which one of the following does not constitute a part of single uriniferous tubule?

biology excretion to maintain homeostasis excretion in other organisms other excretory organ role of other organs in excretion

  1. Distal convoluted tubule

  2. Collecting duct

  3. Bowman's capsule

  4. Loop of Henle

Show answer
Correct Option: B
Explanation:

Collecting ducts are the larger tubes, each receiving the collecting tubules of several nephrons. Collecting duct does not form a part of the uriniferous tubule.