Chapter 7 Question 16 - Case Study What Organelles Are Required To Color Your Cells?

Get access to NCERT Solutions for Class xi Biology Affiliate 8 Jail cell: The Unit Of Life. These solutions enable students to hands prepare for the concepts covered in the term – I CBSE Syllabus 2021-22 for Class 11. Biology NCERT Solutions for Grade xi are formulated by highly experienced academic professionals and kinesthesia members, possessing years of experience and thorough knowledge in their respective fields. Thereby, students are served with the virtually apt and reliable resources for both first term examinations as well the competitive examinations.

At BYJU'S, students are presented with NCERT Solutions which are inclined to the information provided in the NCERT textbook for Course eleven. Hence, students are bodacious that data does non digress from the standard study resource, the textbook.

Download PDF of NCERT Solutions for Grade 11 Biology Chapter eight – Cell: The Unit of measurement Of Life

Access Answers to NCERT Class 11 Biological science Chapter 8 – Cell: The Unit of measurement Of Life

1. Which of the post-obit is not correct?

(a) Robert Brown discovered the cell.

(b) Schleiden and Schwann formulated the cell theory.

(c) Virchow explained that cells are formed from pre-existing cells.

(d) A unicellular organism carries out its life activities within a single jail cell.

Solution:

The reply is (a) Robert Brown discovered the cell

It is wrong because Robert Chocolate-brown discovered nucleus in the prison cell.

2. New cells generate from

(a) bacterial fermentation (b) regeneration of old cells

(c) pre-existing cells (d) abiotic materials

Solution:

The answer is (c) pre-existing cells

iii. Match the following

Column I	Column II
(a) Cristae	(i) Flat membranous sacs in stroma
(b) Cisternae	(2) Infoldings in mitochondria
(c) Thylakoids	(iii) Disc-shaped sacs in Golgi apparatus

Solution:

Column I	Column II
(a) Cristae	(ii) Infoldings in mitochondria
(b) Cisternae	(iii) Disc-shaped sacs in Golgi apparatus
(c) Thylakoids	(i) Flat membranous sacs in stroma

4. Which of the following is right?

(a) Cells of all living organisms have a nucleus.

(b) Both fauna and plant cells have a well divers cell wall.

(c) In prokaryotes, there are no membrane jump organelles.

(d) Cells are formed de novo from abiotic materials

Solution:

The answer is (c) In prokaryotes, there are no membrane-spring organelles.

five. What is a mesosome in a prokaryotic cell? Mention the functions that it performs.

Solution:

A mesosome is a unique membranous construction formed by the extensions of plasma membrane into the cell. It it is establish attached to the nucleoid, information technology is known as septal mesosome and is known every bit lateral mesosome if the mesosome is free from the nucleoid.

Functions of mesosome are as follows

• They assist in cell-wall formation
• They help in DNA replication and distribution to daughter cells.
• They likewise help in respiration, secretion processes, to increase the surface area of the plasma membrane and enzymatic content.

6. How exercise neutral solutes motion across the plasma membrane? Can the polar molecules too motility beyond it in the same fashion? If not, then how are these transported across the membrane?

Solution:

The neutral solutes are lipid-soluble hence they pass through lipid bilayer. No, polar molecules cannot motion across the plasma membrane in the aforementioned style as neutral solutes; they require particular hydrophilic areas for their passage. They become transported by three types of transport mechanisms – ions, channels, permeases and active ship utilising ATP.

7. Name two cell-organelles that are double membrane-bound. What are the characteristics of these ii organelles? State their functions and draw labelled diagrams of both.

Solution:

Two organelles that are double membrane-bound are i) Mitochondria 2) Chloroplasts

Characteristics of mitochondria

The mitochondrion is a double membrane-jump structure with the outer membrane and the inner membrane dividing its lumen distinctly into ii aqueous compartments, i.due east., the outer compartment and the inner compartment.

• Mitochondria is semi-autonomous equally they possess their own Dna.
• Mitochondria is the identify of aerobic respiration.

Characteristics of Chloroplasts

• They are found in plants and euglenoids, variously shaped in lower plants and disc-shaped in higher plants
• They accept specific pigments which imparts colour to the leaves of the plants
• Chloroplasts possess their own DNA.
• Pigments assistance to trap sunlight thereby helps in photosynthesis.
• Consists of membrane-flattened sacs known equally thylakoids located in their matrix. At some locations, thylakoids are stacked and are known every bit gana.

8. What are the characteristics of prokaryotic cells?

Solution:

• The nuclear membrane is absent and the genetic material is not enclosed by an envelope. The naked Deoxyribonucleic acid is found to be coiled in the cytoplasm and is referred to every bit a genophore or nucleoid
• They lack membrane-jump organelles and membrane-bound nucleus
• Jail cell lumen is filled with a fluid known as cytoplasm
• Prokaryotic DNA is situated in the nucleoid of the cell
• Prokaryotic jail cell wall acts as a layer of protection and helps in maintaining cell shape
• Ribosome is the but cytoplasmic organelle that is found in prokaryotic cells

nine. Multicellular organisms take division of labour. Explain.

Solution:

Cells are organized to grade tissues which brand organ and organ system. A cell is an autonomous structure which is capable of conveying out functions on its own. Hence the partition of labour is essential to carry out different functions for increased efficiency and higher survival.

10. The cell is the basic unit of life. Discuss in brief

Solution:

Every plant and beast cells are made of organ systems and organ systems are fabricated up of organs. Organs are constructed by tissues, and tissues are fabricated up of a cluster of cells. Since cells are autonomous structures capable of carrying out functions on their ain, it is said that cell is the bones unit of life.

11. What are nuclear pores? State their function.

Solution:

At several places, the nuclear membrane is surrounded by infinitesimal pores formed by the fusion of 2 membranes called a nuclear pore. They are simple perforations on the nuclear envelope.

Functions:

• Retains the shape of the nucleus
• Known to preserve the stability of the genetic material past safeguarding it from respiratory breakdown occurring in the cytoplasm
• Responsible for the movement of RNA and protein molecules in both directions between the nucleus and the cytoplasm.

12. Both lysosomes and vacuoles are endomembrane structures, nevertheless they differ in terms of their functions. Comment.

Solution:

The endomembrane is an intercellular system reponsible for the flow of materials from i to another office through vesciles. Some of its components are vacuoles, plasma membrane, endoplasmic reticulum, lysosomes and golgi apparatus. Lysosomes are membrane-bound organelles that release lytic enzymes to digest worn-out cells hence they are known as suicidal bags. On the other mitt, vacuoles help cells to maintain their shape. Vacuoles besides store nutrient, water and waste products.

13. Describe the structure of the following with the help of labelled diagrams.

(i) Nucleus (ii) Centrosome

Solution:

i) The nucleus is an oval shaped or round structure having a double membrane containing the genetic material. Information technology consists of five parts, namely – nuclear envelope, nuclear matrix, nucleoplasm, nucleolus and chromatin.

Nuclear envelope – The nucleus is constrained by the nuclear pore which is a double membrane nuclear envelope having tiny pores in the membrane which serve as a aqueduct for substances to pass in and out of the nucleus. The endoplasmic reticulum is connected to the outer membrane which as well contains the ribosomes.

Nucleoplasm – it is the fluid filled in the nucleus containing enzymes, nucleosides, proteins and other factors responsible for the operation of the genetic material. It likewise embeds the chromatin fibres and nucleolus.

Chromatin – found inside the nucleus, they are a fine network of thread-like structures containing Deoxyribonucleic acid and a few basic proteins such as histones, RNA and non-histone proteins. These chromatin fibres during the procedure of cell partition condense to course the chromosomes.

Nucleolus – They are fastened with the chromatin and are round, lightly irregular, naked structures that produce the ribosome subunits. They produce proteins.

(ii) Centrosome

• Consists of 2 cylindrical structures known as centrioles which lie perpendicular to ane some other, organized as a cartwheel
• Engirdled past baggy pericentriolar materials
• Consists of 9 evenly spaced peripheral fibrils of the tubulin protein, wherein each is a triplet and adjacent triplets are linked to each other
• The middle of the centriole is a proteinaceous hub attached to the triplets through radial spokes
• It is critical during prison cell division as information technology organizes the spindle fibres and astral rays

fourteen. What is centromere? How does the position of centromere form the ground of nomenclature of chromosomes? Support your answer with a diagram showing the position of the centromere on different types of chromosomes.

Solution:

Primary constriction present in a chromosome is called the centromere.

Centromere holds ii chromatids of a chromosome.

Based on the position of the centromere, the chromosomes can be classified into four types:

• Metacentric has eye centromere forming two equal arms of the chromosomes.
• Submetacentric chromosomes have centromere slightly away from the middle of the chromosomes resulting in 1 shorter arm and one more than extended arm.
• Acrocentric chromosomes accept centromere situated close to its finish forming i extremely short and ane very long arm.
• The telocentric chromosome has a terminal centromere.

NCERT Solutions for Class 11 Biology Chapter 8 – Cell: The Unit Of Life

NCERT Solutions for Form 11 covers Cell: The Unit of life as the 8th chapter categorized under Unit – three – Jail cell: Structure and Functions of the first term. Unit – 3 constitutes about fifteen marks of the total marks as per past trends, which roughly comes up to a staggering 21% of the total weightage of the question newspaper.

Therefore, it is essential students learn all the chapters covered under unit of measurement 3 thoroughly, which volition be helpful non only for the term – I examinations just will also enable them to face challenging questions appearing in the competitive archway exams.

List of subtopics covered in Chapter 8 – Prison cell: The Unit Of Life

Number	Subtopic
8.i	What is a cell?
viii.2	Cell theory
8.iii	An overview of cell
eight.4	Prokaryotic cells
8.5	Eukaryotic cells

NCERT Solutions for Class eleven Biological science Chapter 8 – Cell: The Unit Of Life

The jail cell is a structural and functional unit of measurement of a living entity. This chapter provides details about cells, the composition of cells, etc. Some organisms possess a single cell known equally unicellular organisms while some others are composed of multiple cells, referred to as multicellular organisms.

The chapter also takes students through two broad groups of nomenclature – eukaryotes and prokaryotes. The prison cell consists of different constituents some of which are absent in the constitute cell, while some are absent in an animal cell.

Key Features of NCERT Solutions for Class 11 Biology Affiliate viii – Cell: The Unit Of Life

• NCERT Solutions cover all the fundamental concepts
• Actress attention toward answering methodologies
• Utilize of tables and diagrams wherever necessary
• Concepts are elucidated in a simple fashion
• Solutions are researched and reviewed past subject field matter experts
• Solutions are available in a gratuitous, downloadable format

Oft Asked Questions on NCERT Solutions for Course 11 Biology Chapter 8

Explain the functions of Memosome from the Chapter 8 of NCERT Solutions for Class 11 Biology.

The functions of Memosome from the Chapter 8 of NCERT Solutions for Class eleven Biology are –
i. Memosome helps in cell wall formation.
ii. Deoxyribonucleic acid replication and distribution is washed past Memosome.
3. Memosome assist in secretion and respiration processes to increase the surface area of enzymatic content and plasma membrane.

What are the concepts included in the Chapter 8 of NCERT Solutions for Course eleven Biology?

The concepts included in the Affiliate 8 of NCERT Solutions for Course 11 Biology are –
8.1 – What is a cell?
eight.2 – Cell theory
8.3 – An overview of cell
viii.4 – Prokaryotic cells
8.5 – Eukaryotic cells

Why is the NCERT Solutions for Class eleven Biology Chapter eight considered to exist the best report material for the CBSE students?

1. All the bones concepts are explained conspicuously.
2. Numerous methodologies in answering complex questions are followed.
3. Diagrams and tables are used wherever necessary to aid visual learning.
iv. The experts bear vast inquiry on each concept before preparing the solutions.
5. PDF format of solutions tin exist downloaded for free from BYJU'S.

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