How does cytokinesis in plant
Question: How does cytokinesis in plant cells differ from that in animal cells? Solution: Cytokinesis in plants occurs by cell plate formation. Cell plate formation starts from the centre and grows to the periphery....
Read More →Name a cell that is found arrested in diplotene
Question: Name a cell that is found arrested in diplotene stage for months and years. Comment in 2-3 lines how it completes the cell cycle? Solution: The oocyte of mammalian females gets arrested in the diplotene stage. The oocyte grows and forms secondary follicle and then it gets arrested at the diplotene stage. As the woman attains the sexual maturity first meiosis gets completed. Meiosis occurs one by one in the egg, which is released from the ovary....
Read More →Comment on the statement – Meiosis enables
Question: Comment on the statement Meiosis enables the conservation of specific chromosome number of each species even though the process per se, results in a reduction of chromosome number. Solution: A diploid zygote is formed when the two haploid cells called gametes fused during fertilization. If meiosis is absent than two diploid gametes would be produced which will result in the formation of tetraploid zygote. To conserve the chromosome, number meiosis is very important....
Read More →If the solve the problem
Question: $\int \cos 3 x \cos 4 x d x$ Solution: We know $2 \cos A \cos B=\cos (A-B)+\cos (A+B)$ $\therefore \cos 4 x \cos 3 x=\frac{\cos x+\cos 7 x}{2}$ $\therefore$ The above equation becomes $\Rightarrow \int \frac{1}{2}(\cos x-\cos 7 x) d x$ $\Rightarrow \frac{1}{2}\left(\int \cos x d x-\int \cos 7 x d x\right)$ We know $\int \cos a x d x=\frac{1}{a} \sin a x+c$ $\Rightarrow \frac{1}{2}\left(\sin x-\frac{1}{7} \sin 7 x\right)$ $\Rightarrow \frac{7 \sin x-\sin 7 x}{14}+C$...
Read More →Two key events take place,
Question: Two key events take place, during S phase in animal cells, DNA replication and duplication of the centriole. In which parts of the cell do events occur? Solution: DNA replication occurs in the nucleus and centriole duplicates in the cytoplasm....
Read More →Name the pathological condition
Question: Name the pathological condition when uncontrolled cell division occurs. Solution: This is called malignancy caused due to cancer....
Read More →Both unicellular and multicellular organisms
Question: Both unicellular and multicellular organisms undergo mitosis. What are the differences, if any, observed in the process between the two? Solution: In prokaryotes amitosis takes place, the cell directly divides into two daughter cells. Whereas in multicellular organisms, proper steps of cell division occur; first the karyokinesis takes place then cytokinesis occurs....
Read More →Mitosis results in producing two cells
Question: Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities occur during mitosis? a. Nuclear membrane fails to disintegrate b. Duplication of DNA does not occur c. Centromeres do not divide d. Cytokinesis does not occur Solution: a. Nuclear membrane fails to disintegrate, then the spindle fibre would not reach the chromosomes. b. Duplication of DNA does not occur, then the whole cell cycle would get arres...
Read More →The following events occur during the various phases
Question: The following events occur during the various phases of the cell cycle, Name the phase against each of the events. a. Disintegration of nuclear membrane _________________________ b. Appearance of nucleolus _________________________ c. Division of centromere _________________________ d. Replication of DNA _________________________ Solution: a. Early Prophase b. Late Telophase c. Anaphase d. S phase...
Read More →While examining the mitotic stage in a tissue,
Question: While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number? Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa? Solution: The phenomenon of the existence of two types of chromosome no. in a different cell of the body is called mosaicism. This may arise due to non-disjunction of chromosomes or lag of ...
Read More →A cell has 32 chromosomes.
Question: A cell has 32 chromosomes. It undergoes mitotic division. What will be the chromosome number (N) during metaphase? What would be the DNA content (C) during anaphase? Solution: Both N and C will be 32. This is because DNA is replicated during the S phase, after that it would remain the same during equational division....
Read More →Mitochondria and plastids have their DNA (genetic material).
Question: Mitochondria and plastids have their DNA (genetic material). What is known about their fate during nuclear division like mitosis? Solution: DNA present in mitochondria in plastids are called the extrachromosomal DNA. They are independent of the nuclear division of nuclear DNA. Hence, no effect of mitosis is seen on extrachromosomal DNA....
Read More →State the role of centrioles other
Question: State the role of centrioles other than spindle formation. Solution: Centriole forms microtubule and forms the basal body of flagella....
Read More →If the solve the problem
Question: $\int \sin 4 x \cos 7 x d x$ Solution: We know $2 \sin A \cos B=\sin (A+B)+\sin (A-B)$ $\therefore \sin 4 x \cos 7 x=\frac{\sin 11 x+\sin (-3 x)}{2}$ We know $\sin (-\theta)=-\sin \theta$ $\therefore \sin (-3 x)=-\sin 3 x$ $\therefore$ The above equation becomes $\Rightarrow \int \frac{1}{2}(\sin 11 x-\sin 3 x) d x$ $\Rightarrow \frac{1}{2}\left(\int \sin 11 x d x-\int \sin 3 x d x\right)$ We know $\int \sin \mathrm{ax} \mathrm{dx}=\frac{-1}{\mathrm{a}} \cos \mathrm{ax}+\mathrm{c}$ $\R...
Read More →In which phase of meiosis is the following formed?
Question: In which phase of meiosis is the following formed? Choose the answers from hint points given below. a. Synaptonemal complex ____________________________ b. Recombination nodules ____________________________ c. Appearance/activation of ____________________________ enzyme recombinase d. Termination of chiasmata _ ___________________________ e. Interkinesis ____________________________ f. Formation of dyad of cells _ ___________________________ Hints : 1) Zygotene, 2) Pachytene, 3) Pachyt...
Read More →It is observed that heart cells do not exhibit cell division.
Question: It is observed that heart cells do not exhibit cell division. Such cells do not divide further and exit ___________ phase to enter an inactive stage called ___________ of cell cycle. Fill in the blanks. Solution: G1 phase, G0 phase....
Read More →It is said that the one cycle of cell division
Question: It is said that the one cycle of cell division in human cells (eukaryotic cells) takes 24 hours. Which phase of the cycle, do you think occupies the maximum part of the cell cycle? Solution: Interphase is the phase of the cycle takes 23 hours out of 24 hours....
Read More →Evaluate:
Question: Evaluate: $\int \sin x \sqrt{1-\cos 2 x} d x$ Solution: $\Rightarrow 2 \sin ^{2} x=1-\cos 2 x$ We can substitute the above result in the given equation $\therefore$ The given equation becomes $\Rightarrow \int \sin x \sqrt{2 \sin ^{2} x}$ $\Rightarrow \int \sqrt{2} \sin ^{2} x$ $\sin ^{2} x=\frac{1-\cos 2 x}{2}$ $\Rightarrow \frac{\sqrt{2}}{2} \int 1-\cos 2 x d x$ $\Rightarrow \frac{1}{\sqrt{2}} \int d x-\frac{1}{\sqrt{2}} \int \cos 2 x d x$ $\Rightarrow \frac{x}{\sqrt{2}}-\frac{1}{2 \...
Read More →At what stage of the cell cycle does
Question: At what stage of the cell cycle does DNA synthesis take place? Solution: At the S-phase of the cell cycle, DNA synthesis takes place....
Read More →An anther has 1200 pollen grains.
Question: An anther has 1200 pollen grains. How many pollen mother cells must have been there to produce them? Solution: 1 pollen mother cell 4 pollen grain Therefore, no. of PMC = 1200/4 = 300 pollen grains....
Read More →If the tissue has at a given time 1024 cells,
Question: If the tissue has at a given time 1024 cells, how many cycles of mitosis had the original parental single-cell undergone? Solution: 2x=1024 X=10 Therefore, the parent will undergo 10 rounds of mitosis....
Read More →Evaluate:
Question: Evaluate: $\int \cos ^{2} n x d x$ Solution: We know, $\cos ^{2} x=\frac{1+\cos 2 x}{2}$ $\therefore$ The given equation becomes, $\Rightarrow \int \frac{1+\cos \mathrm{n} \mathrm{x}}{2} \mathrm{dx}=\int \frac{1+\cos 2 \mathrm{nx}}{2} \mathrm{dx}$ We know $\int \cos \mathrm{ax} \mathrm{dx}=\frac{1}{\mathrm{a}} \sin \mathrm{ax}+\mathrm{c}$ $\Rightarrow \frac{1}{2} \int d x+\frac{1}{2} \int \cos (2 n x) d x$ $\Rightarrow \frac{x}{2}+\frac{1}{4 n} \sin (2 n x)+c$...
Read More →What attributes does a chromatid require
Question: What attributes does a chromatid require to be classified as a chromosome? Solution: When chromatids are attached to the centromere it is termed as a chromosome....
Read More →Which part of the human body should
Question: Which part of the human body should one use to demonstrate stages in mitosis? Solution: Tissues near to the cheeks can be taken to demonstrate stages in mitosis....
Read More →Given that the average duplication time
Question: Given that the average duplication time of E.coli is 20 minutes, how much time will two E.coli cells take to become 32 cells? Solution: 2 4 8 16 32 It takes 80 mins....
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