C. SHORT ANSWER TYPE
1. It is said that the protoplasm cannot be analysed
chemically. Why?
2. What is the difference between an organ and an
organelle?
3. Do you think the cells of an elephant would be larger
than the cells of a rat? Explain briefly.
4. Differentiate between the following pairs of terms:
(a) Protoplasm and cytoplasm
(b) Nucleolus and nucleus
(c) Centrosome and chromosome
(d) Cell wall and cell membrane
(e)
Plant cell and animal cell
Prokaryotes and eukaryotes.
Answers
Answer:
1) The protoplasm cannot be analysed chemically because it has complex organic and living cell organelles which can disintegrate if chemicals are added to analyse. Also due to complexity of physical and chemical properties the ultimate chemical nature of protoplasm cannot be determined.
2)The main difference between organ and organelle is that organ is a large part of an organism, composed of tissues which perform similar functions whereas organelle is a specialized structure found inside cells, which carries out a specific life process. Organelles occur in all eukaryotes.
3)The cells of an elephant would be of the same size as the cells of a rat. The size of cells does not vary within the organisms, however, the number of cells varies from one organism to another. A larger animal like an elephant will have the number of cells as compared to a smaller animal like a rat.
4)(a) Protoplasm and cytoplasm - Protoplasm is the content of the cell including the cell membrane, cytoplasm and the cell nucleus whereas cytoplasm is the jelly-like substance surrounding the nucleus within the cell membrane. The cytoplasm contains the cell organelles like mitochondria, ribosomes etc.
(b) Nucleolus and nucleus - The nucleolus is a structure found in the nucleus of cells and it forms around specific chromosomal regions in the nucleus of eukaryotic cells and is made up of proteins and ribonucleic acids. The nucleus is a membrane-enclosed organelle found in eukaryotic cells.
(c) Centrosome and chromosome - Centrosome is an organelle in the cell which is responsible in the division of cells. While chromosomes are highly condensed coiled chromatin fibers that is present inside the nucleus.
(d) Cell wall and cell membrane - Cell wall is found only in plant cells and is made up of cellulose whereas cell membrane is found in both plant and animal cells and is made up of lipids and proteins.
(e) Plant cell and animal cell - Animals cells store energy in the form of the complex carbohydrate glycogen. Plant cells store energy as starch.
(f) Prokaryotes and eukaryotes - Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.
Explanation:
hope this helps you.
Answer:
1. The protoplasm cannot be analysed chemically because it has complex organic and living cell organelles which can disintegrate if chemicals are added to analyse. Also due to complexity of physical and chemical properties the ultimate chemical nature of protoplasm cannot be determined.
2. The main difference between organ and organelle is that organ is a large part of an organism, composed of tissues which perform similar functions whereas organelle is a specialized structure found inside cells, which carries out a specific life process. Organelles form cells.
3. No. The cells of an elephant is not larger than the cells of a rat because their cells number will increase.It means Elephant has more number of cells compared to cells of a rat.The cells of rat and elephant are similar. Just because an animal is bigger in size does not mean the cell size is bigger. It only means that the number of cells is more in bigger animals than in smaller ones.
4. a. Protoplasm of a cell includes the cytoplasm of the cell as well as the Nucleus while the cytoplasm does not include Protoplasm
b. The nucleolus is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome biogenesis. Nucleoli also participate in the formation of signal recognition particles and play a role in the cell's response to stress
c. Centrosome is an organelle in the cell which is responsible in the division of cells. While chromosomes are highly condensed coiled chromatin fibres that is present inside the nucleus
d. Plant Cell Animal Cell
Plant Cell Animal CellPlastids
Plant Cell Animal CellPlastidsPresent Absent
Plant Cell Animal CellPlastidsPresent AbsentVacuoles
Plant Cell Animal CellPlastidsPresent AbsentVacuolesFew large or a single, centrally positioned vacuole Usually small and numerous
e. Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles. Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus that holds genetic material as well as membrane-bound organelles.
Explanation:
hope it helps you dear follow me