Tag: division for growth and reproduction
Questions Related to division for growth and reproduction
Mitosis and meiosis take place respectively in
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Meristem and gametangia
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Gametangia and meristem
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Permanent tissues and secretory tissues
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Secretory tissues and permanent tissues
- During mitosis, chromosome number remains the same and cells increase in number. Mitosis is the cell division in meristematic tissue.
- Daughter cells produced after meiosis are haploid. Meiosis is the cell division that occurs in gametangia to produce gametes.
Meiosis and mitosis differ from each other because in meiosis
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The four nuclei formed are not similar to parental ones
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Homologous chromosomes pair exchange parts
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Number of chromosomes gets halved
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All of the above
- Meiosis is the type of cell division in which homologous chromosomes separate after an exchange of fragments. As a result of meiosis, four haploid cells are produced which are all genetically different from each other.
- This is due to the process of crossing over or exchange of segments between homologous chromosomes.
The number of chromatids, in a chromosome at anaphase is
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2 in mitosis and 1 in meiosis
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1 in mitosis and 2 in meiosis
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2 each in mitosis and meiosis
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2 in mitosis and 4 in meiosis
Meiosis occurs in two stages meiosis I and meiosis II. During meiosis I, homologous chromosomes separate and the number of chromosomes in daughter cells get reduced to half. This division is known as reductional division. During meiosis II, centromere splits and the chromosome number remains the same in the daughter cells. Hence, meiosis II is known as equational division. Hence, the number of chromatids in a chromosome at anaphase is 1 in mitosis and 2 in meiosis.
Identify the wrong statement about meiosis.
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Pairing of homologous chromosomes
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Four haploid cells are formed
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At the end of meiosis number of chromosomes are reduced to half
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Two cycle of DNA replication occur
Meiosis is a specialized type of cell division that reduces the chromosome number by half, creating four haploid cells. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. The two meiotic divisions are known as Meiosis I and Meiosis II.
Which of the following statement is not true for meiosis?
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It is a process in which the chromosomes duplicate only once
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It is a process in which the cell divides twice
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The karyokinesis skips one of the phases compared to mitosis
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It results in the formation of four haploid cells
The stage of karyokinesis does not skip any phase in mitosis as compared to meiosis because the cell division phases are the same in meiosis and mitosis.
........... is used for preparing standard solutions in which it is always desired to maintain a constant pH.
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Buffer
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Plasma
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Serum
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None of the above
A buffer is a solution that resists a change in pH upon the addition of acidic or basic components. To effectively maintain a pH range, a buffer consists of a weak conjugate acid-base pair. It is either a weak acid and its conjugate base, or a weak base and its conjugate acid. Thus the correct answer is option A.
A buffer is a mixture of
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Weak acid and its salt with a strong base
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Strong acid and its salt with a strong base
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Weak acid and its salt with a weak base
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None of the above
The proton-pumps provide energy to cells through.
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pH gradient and electro potential gradient
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ATP and ADP
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Auxins and hormones
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Carbolwdrates and lipids
If the activity of an enzyme is constant over a broad range of pH values,it is likely that
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only ionizing groups on the enzyme participate in the reaction
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only ionizing groups on the substrate participate in the reaction
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ionizing groups on the enzyme and substrate participate in the reaction
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the temperature should be changed in order to observe a pH effect
Which of the following statements is correct for the pollen tube
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It shows chemotactic movement
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It shows only tip growth
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It is composed of three non-cellular zones
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It shows radial cytoplasmic streaming
The movement of pollen tube towards embryosac though style is chemotactic as it secrets pectinases and other hydrolytic enzymes to create a passage for its entry into style .