cell biology Quiz-28
Dear Readers,
NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions.
About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus.
Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced.
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Q1. In eukaryotic cells, genetic material or DNA is organised into
Solution
(c) In eukaryotic cells, genetic material is organised into chromosomes. DNA is bounded with histone proteins to form chromatin
(c) In eukaryotic cells, genetic material is organised into chromosomes. DNA is bounded with histone proteins to form chromatin
Q2. The nucleus is separated from surrounding cytoplasm by nuclear membrane, which is
Solution
(b) Nuclear membrane with pores separates nucleus from surrounding cytoplasm.
(b) Nuclear membrane with pores separates nucleus from surrounding cytoplasm.
Q3. I. It is the extension of plasma membrane into the cytoplasm
II. It helps in cell wall formation, DNA replication, respiration, secretion processes, increases the surface area of plasma membrane and enzymatic contents. It also helps in cytokinesis
III. It I the characteristic of bacterial cells
The above features are attributed to bacteria
Solution
(c) Mesosome is the extension of plasma membrane into the cytoplasm It helps in cell wall formation, DNA replication, respiration, secretion processes, increases the surface area of plasma membrane and enzymatic contents. It also helps in cytokinesis. It is generally found in bacterial cells
(c) Mesosome is the extension of plasma membrane into the cytoplasm It helps in cell wall formation, DNA replication, respiration, secretion processes, increases the surface area of plasma membrane and enzymatic contents. It also helps in cytokinesis. It is generally found in bacterial cells
Q4. What are those structures that appear as ‘beads-on-string’ in the chromosomes when viewed under electron microscope?
Solution
Nucleosome is sub-microscopic sub-unit of chromatin which is formed by wrapping of DNA over a core of histone proteins. The term was coined by Oudet et..el.., (1975). It is oblate structure with a length of 10nm and a thickness of 5-5.7nm. Its core is called nu-body. The latter is formed of four pairs of histone moleculesH2,A ,H2B,H3 and H H 4 . DNA makes 1.75 turns over the octamer to form a nucleosome. Two adjacent nucleosomes are connected by a short segment of unboud DNA called linker DNA. A fifth type of histone called H 1 is attached over the linker DNA. Nucleosomes appear as ‘beads-on-string’ in the chromosomes under electron microscope.
Nucleosome is sub-microscopic sub-unit of chromatin which is formed by wrapping of DNA over a core of histone proteins. The term was coined by Oudet et..el.., (1975). It is oblate structure with a length of 10nm and a thickness of 5-5.7nm. Its core is called nu-body. The latter is formed of four pairs of histone moleculesH2,A ,H2B,H3 and H H 4 . DNA makes 1.75 turns over the octamer to form a nucleosome. Two adjacent nucleosomes are connected by a short segment of unboud DNA called linker DNA. A fifth type of histone called H 1 is attached over the linker DNA. Nucleosomes appear as ‘beads-on-string’ in the chromosomes under electron microscope.
Q5. Which of the following pairs lack the unit membrane?
Solution
(c) Ribosome (site of protein synthesis) and nucleolus (site of rRNA synthesis) are amembranous cell organelles.
(c) Ribosome (site of protein synthesis) and nucleolus (site of rRNA synthesis) are amembranous cell organelles.
Q6. The plasma membrane consists mainly of
Solution
(b) According to fluid mosaic given by singer and Nicolson (1972), plasma membrane consists of a continuous bilayer of phospholipid molecules, in which globular proteins are embedded.
(b) According to fluid mosaic given by singer and Nicolson (1972), plasma membrane consists of a continuous bilayer of phospholipid molecules, in which globular proteins are embedded.
Q7. Which of the following enzymes helps in crossing plasma membrane?
Solution
(d) Membrane proteins that speed the movement of solute across a membrane by facilitating diffusion are called transporters or permeases.
(d) Membrane proteins that speed the movement of solute across a membrane by facilitating diffusion are called transporters or permeases.
Q8. Which of the following is a part of endomembrane system of eukaryotic cell?
Solution
(d) Golgi complexes or Golgi bodies and ER form the endomembranous system of eukaryotic cell. Golgi bodies are made up of various membranous systems, e.g.,., cisternae, vesicles and vacuoles.
(d) Golgi complexes or Golgi bodies and ER form the endomembranous system of eukaryotic cell. Golgi bodies are made up of various membranous systems, e.g.,., cisternae, vesicles and vacuoles.
Q9. Protoplast denotes the ….. of protoplasm present in a cell
Solution
(a) Protoplasm denotes the whole of protoplasm
(a) Protoplasm denotes the whole of protoplasm
Q10. The term mitochondria was given by
Solution
(a) Benda (1897) gave the term ‘mitochondria’ after Richard Altmann (1894) who described them as ‘bioplasts’.
(a) Benda (1897) gave the term ‘mitochondria’ after Richard Altmann (1894) who described them as ‘bioplasts’.
