Tag: biology

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Questions Related to biology

Multiple choice biology food components and nutrition water as nutrient basics of water pollution sources of water

Living cell contains $60 - 75$% water. Water present in human body is

  1. $60 - 65$%
  2. $50 - 55$%
  3. $75 - 80$%
  4. $65 - 70$%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Our cells are made of 60-75% water, hence most of the enzymes and protein molecules, our genetic material, all are water soluble and are evolved in a way to co-exist in water surrounding environment. Thus our proteins are folded in a way where the hydrophobic amino acid residues are folded inside the protein and hydrophilic residues face the hydrated outer environment. Similarly our DNA, RNA are all water soluble. Since the structural and functional unit of our body, consists of 60-75% of water hence, the entire human body is expected to have similar water content.
So, the correct answer is '65−70%'.
Multiple choice biology food components and nutrition water as nutrient basics of water pollution sources of water

When a litre of water is introduced in human blood, 

  1. BMR decreases

  2. RBCs collapse and urine production increases

  3. BMR increases

  4. RBCs collapse and urine production decreases
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Introducing a large volume of water into the blood decreases its osmolarity. This causes water to move into red blood cells (osmosis), potentially causing them to swell and burst (hemolysis), and triggers the kidneys to increase urine production to restore balance.

Multiple choice biology photosynthesis in higher plants types of chlorophyll pigments photosynthetic pigments

Which of the below statements is/are not correct regarding chlorophyll a molecule?

(i) Molecule formula of chl a is $C _{55}H _{72}O _5N _4Mg$
(ii) It is the primary photosynthetic pigment.
(iii) In the pure state, it is red in colour and thus it absorbs more blue wavelength of light than the red wavelength. 
(iv)It is a soluble in water as well as petroleum ether.

  1. (i) and (iii)

  2. (iii) and (iv)

  3. (ii) only

  4. (iv) only
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chlorophyll a is the primary photosynthetic pigment, which is bluish green in the pure state. It has an empirical formula $C _{55}H _{72}O _5N _4Mg$and molecular weight of $893$. It absorbs more red wavelength of light than violet blue . It is soluble in a number of organic solvents such as petroleum ether. 

So, the correct answer is ' In the pure state, it is red in colour and thus it absorbs more blue wavelength of light than the red wavelength and It is a soluble in water as well as petroleum ether'.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Generally, decline in hearing power begins after the age of 

  1. 50 years

  2. 30 years

  3. 40 years

  4. 10 years
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ageing is the process where there is a continuous decline in the metabolism of the body. The hearing power also declines after the age of 40 years. Presbycusis is the term which is generally used for hearing impairment due to old age. It is mainly caused due to degeneration of the cochlea or associated structures of the inner ear or auditory nerves.

So, the correct answer is option C.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Cell which keeps changing it's shape is called

  1. Spirilla

  2. Pleomorphic

  3. Symbiont

  4. Gram negative
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pleomorphic organisms, such as certain bacteria like Mycoplasma, lack a rigid cell wall and can readily alter their size and shape in response to environmental conditions. Spirilla are rigid spiral-shaped bacteria, while symbionts and gram negative refer to ecological relationships or cell wall staining properties.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Power is regeneration is poor in.

  1. Brain cell

  2. Bone cell

  3. Chondroblasts

  4. Striated muscles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Brain cells (neurons) have very limited capacity for regeneration compared to other tissues like bone or muscle. This is why injuries to the central nervous system are often permanent.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Storage sprouting of potato can be prevented by 

  1. IAA

  2. Maleic hydrazide

  3. Cytokinins

  4. Gibberellins
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Maleic hydrazide : It is a growth retardant which checks cell division. So during seed storage this is applied for checking sprouting of potato tubers so that the importance of potato may not be lowered down.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

The process of cell death involving DNA cleavage in cells is known as

  1. Necrosis

  2. Apoptosis

  3. Cytokinesis

  4. Endocytosis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Apoptosis is the process in living cells which results in the death of cells that are damaged, attacked by pathogens, cancerous cell, abnormal cell, etc. Such cells are identified by the cells of the immune system followed by the production of proteins that kills the cell by DNA cleavage. It is also called programmed cell death. Thus the correct answer is option A. 
Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Glucose and amino acids are absorbed through the following part of villus.

  1. Epithelial cells

  2. Blood capillary

  3. Lymphatic vessel

  4. All
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glucose and amino acids are absorbed through the epithelial cells (enterocytes) of the villi in the small intestine. From there, they pass into the blood capillaries.