Biology Cell Structure

Explanation

In comparing plant and animal cells, it is true that plant cells have cellulose cell walls and animal cells do not. Additionally, plant cells typically have one large vacuole while animal cells have many small vacuoles. However, the statement that plant cells do not have a plasma membrane, as mentioned in statement 2, is incorrect. Therefore, the correct answer is option (c) - 1 and 3 only.

Explanation

In a cold chamber, fruits stored have a longer shelf life due to the decreased rate of respiration. This reduction in respiration helps control the production of ethylene, a gas that aids in the ripening process of fruits. By managing ethylene production, the fruits can be preserved for a longer period.

Explanation

Fruits stored in a cold chamber have a longer storage life because the low temperature slows down the rate of respiration in the fruits. Respiration is the process by which fruits give out ethylene gas, which aids in ripening. By reducing the rate of respiration, the cold chamber helps to control the production of ethylene, thus prolonging the storage life of the fruits.

Explanation

The use of stem cells, which are often mentioned in the news, has multiple applications. They are not limited to mammals and can be used for both screening new drugs and medical therapies. The correct statement is that stem cells can be used for both screening new drugs and for medical therapies.

Explanation

Comb jellies, also known as Ctenophores, exclusively reproduce through sexual reproduction.

Explanation

In the case of Amoeba, it is correct that it reproduces through fission (Assertion A is true). However, it is not accurate that all unicellular organisms reproduce through asexual methods (Reason R is false).

Explanation

In a situation where a person's blood group is unknown and urgent blood transfusion is required due to a serious accident, the safest blood group to transfuse is O, Rh–, which is known as the universal blood donor type. This is because O– blood group lacks both A and B antigens on the red blood cells.

Explanation

Metastasis refers to the spread of cancer cells from the original site to other areas or organs in the body, such as the brain or liver.

Explanation

In addition to the nucleus, the mitochondrion is the organelle in the cell that contains DNA. Both plant chloroplasts and animal cells also have DNA in mitochondria.

Explanation

The key organelles involved in protein synthesis are the Ribosome and Endoplasmic Reticulum. The Ribosome acts as the main location where proteins are synthesized, while the Endoplasmic Reticulum provides a platform for this process to occur efficiently.

Explanation

Apoptosis refers to the regulated cell death in living organisms. This process takes place as part of the routine maintenance of cells in multicellular organisms.

Explanation

Canola is a type of mustard or rapeseed that has been specifically bred to have a low erucic acid content, making it suitable for producing edible oil.

Explanation

Starch and cellulose are both plant-derived polymers made up of glucose molecules. However, it is incorrect to say that both of them give a blue-black color with iodine. In reality, only starch reacts with iodine to produce this distinct color, while cellulose does not show any color change when exposed to iodine.

Explanation

Aerobic respiration refers to the process where glucose is fully converted into carbon dioxide and water in the presence of oxygen, leading to the release of energy.

Explanation

Proteins are complex organic compounds consisting of amino acids connected by peptide bonds.

Explanation

In this biology question, we have to match physiological processes with the corresponding cell organelles. Photosynthesis takes place in chloroplasts, mineral uptake occurs through the plasma membrane, respiration happens in mitochondria, and protein synthesis is carried out by ribosomes. The correct match is Photosynthesis-Chloroplasts, Mineral uptake-Plasma membrane, Respiration-Mitochondria, and Protein synthesis-Ribosomes, which corresponds to option (a).

Explanation

The amnion is a protective membrane that shields the developing embryo from drying out through a fluid-filled area known as the amniotic cavity.

Explanation

Karl von Frisch was awarded the Nobel Prize for his work in decoding the language of bees.