on DNA and chromosomes, only knowledge based questions can be given. Practice of one question for each model is enough to answer any type of problem. For long term students there won't be any difficulty in these chapters. Little additional information regarding centrosome and centriole in chapter 9 and in biomolecules information given in the Table 3 regarding secondary metabolites has to be remembered thoroughly.
Important information for NEET 2017
Cell theory proposed by Schleiden and Schwann.
� Schwann reported that animal cells are covered by "plasma membrane" and plant cell by cell wall.
� Rudolf Virchow modified the cell theory by adding that cells divide and new similar cells are formed from pre-existing cells (Omnis cellula-e-cellula).
� Cytoplasm is the arena of various kind of cellular activity and keep the cell in a living state.
� Prokaryotes do not show membrane bound cell organelles.
� Ribosomes are 70S and 80S. Prokaryotes, chloroplast, Mitochondria show 70S ribosomes.
� Ribosomes are not membrane bound. In eukaryotes ribosomes are present in the cytoplasm, on the
endoplasmic membrane and inside the chloroplasts and mitochondria.
� Plasmids are self replicating circular or ring shaped DNA present in certain bacterial cells.
� Plasmids impart antibiotic resistance to the bacteria. They are responsible for producing enzymes and toxins.
� Plasmids also participate in transfer of genetic characters during conjugation to other bacteria. It monitors the transformation in bacteria.
� Gram +ve & Gram -ve staining of bacteria is the cell wall property.
� Slime layer and capsule are made up of polysaccharide and referred together as glycocalyx.
� Mesosomes are invaginations of the plasma membrane.
� Mesosomes functions in respiration, reproduction and absorption.
� Flagella, pili and fimbriae are external appandages. Pili and fimbriae are helpful in attaching to the
surface of the substratum or other bacterial surface (pili).
� Flagella in bacteria shows 3 parts - Basal body, hook and filament.
� Siger and Nicolson proposed Fluid Mosaic model.
� With fluid mosaic model transport of different substances can be explained easily.
� In algae cell walls are made up of Cellulose, galactans, Mannans and minerals.
� Lignin, suberin and cutin are secondary wall material.
� Middle lamellum is the outer most layer of the cell wall and is made up of calcium pectates.
� Endomembrane system includes endoplasmic membrane(ER), golgicomplex, lysosomes and vacuole.
� ER divides cytoplasm into compartments-luminal side (inside ER) and extra luminal side(cytoplasm).
� In animal cells lipid like steroidal hormones are synthesized.
� ER synthesizes Lipids. Rough ER with its ribosomes attached participates in protein synthesis.
� Under starvation conditions lysosomes dissolve cellular contents. This is autolysis.
� Cytoskeleton is collectively microfilaments, micro tubules and intermediate filaments.
� During cell division in animals and lower plants centrosome divides into two centrioles.
� Amino acids at neutral pH exist in zwitter ion state.
� Aromatic aminoacids are Tyrosine, Phenylalanine and Tryptophane.
� Simplest amino acid is Glycine. Lysine is basic and Valine is neutral.
� Fatty acids are found esterified with glycerols. Oils have lower melting points.
� G0 phase is a quiescent phase without activity and division.
� During metaphase of mitosis chromatids are separated. During anaphase of Meiosis-I bivalents are separated.
� The longest phase in meiosis is meiosis-I. In meiosis-I it is prophase-I. In prophase-I it is pachytene. In Human females pachytene takes nearly 50 years.
� Meiosis occurs only in sex cells. Mitosis occurs in haploid or diploid cells.
� In meiosis cytokinesis takes place at the end of Meiosis-I or at the end of Meiosis-II. With the advent of NEET importance of this chapter has increased. At any time five questions can be asked from this chapter. Second year "Enzymes" chapter is part of "Biomolecules" of the first year in the NCERT books
AP EAMCET 2016 Question
1. Select the correct statements.
A) H1 histone molecule lies inside the nucleosome core and seals the two turns of DNA
B) Acrocentric chromosome has one extremely short and one very long arm
C) The association between positively charged DNA and negatively charged histones allows
for meaningful DNA packaging inside the nucleus.
D) A few chromosomes have nonstaining secondary constrictions at a constant location and gives the appearance of a small fragment called satellite.
1) A, C
2) B, C
3) B, D
4) C, D
2. Assertion (A): Eukaryotic cell shows extensive compartmentalization of cytoplasm.
Reason (R): Presence of membrane bound organelles is an important character in prokaryotes.
1) Both (A) and (R) are true and (R) is the correct explanation of (A)
2) Both (A) and (R) are true and (R) is not the correct explanation of (A)
3) (A) is true but (R) is false
4) (A) is false but (R) is true
3. Arrange the following compounds in descending order on the basis of number of carbon atoms present in them.
A) Palmitic acid
B) Serine
C) Ribose
D) Arachidonic acid
E) Glucose
1) D C A B E
2) B C E A D
3) D A E C B
4) C B A D E
4. Arrange the following in descending order.
A) Number of bivalents formed during meiosis of a spore mother cell of Ophioglossum.
B) Number of chromatids seen on equatorial at metaphase I in pollen mother cell of Haplopappus gracilis during meiosis.
C) Number of chromosomes found at one pole after anaphase II during meiosis in butterfly
D) The total number of chromosomes in all daughter cells formed during meiosis from one megaspore mother cell in potato
1) B D C A
2) A C D B
3) A D C B
4) D C B A
5. Which cell organelle is involved in the breakdown of fatty acids?
1) Golgi apparatus
2) Vacuole
3) Peroxysome
4) ER
6. Identify the correct pair of statements.
I) Collagen is a heteropolymer
II) Cellulose possess complex helices in its structure.
III) Phosphodiester bond is present in triglyceride
IV) The triplet codon for the aminoacid having CH2-OH as 'R' group is AGU
1) I, IV
2) II, IV
3) I, III
4) II, III
7. The chromosome number of a megaspore of a plant 'A' and an endosperm cell od plant 'B' together equals to the chromosome number in the endosperm cell of maize plant. Plant 'A' and plant 'B' respectively are:
1) Rice, Haplopappus
2) Potato, Haplopappus
3) Potato, Apple
4) Onion, Rice
8. The correct sequence of the events that take place during meiotic division:
I) Crossing-Over
II) Appearance of recombinant nodules
III) Terminalisation of chiasmata
IV) Synaptonemal complex formation
1) II, III, IV, I
2) IV, II, I, III
3) I, III, II, IV
4) IV, I, III, II
