Answer:
Contraction.
Explanation:
Muscle tissues are defined as they are elastic and extensible in nature. In other words it's also defined as they are able to stretched and returned to its original size and shapes. A unique feature of muscle tissue is they are able of contractile in nature. With the help of this contraction they are able to sliding myosin and actin filaments which are present in muscles tissues.
Basically muscle tissues are three types:
1) Skeletal muscle: They are strong and rapid in contraction.
2) Cardiac muscle: They are strong in contraction.
3) Smooth muscle tissues: They are slow and weak in contraction.
1.1
Meiosis I
The first meiotic division: diploid → haploid
Prophase I: Chromosomes condense, nuclear membrane dissolves, homologous chromosomes join and occurs crossing over.
Metaphase-I: the homologous chromosomes align in the middle of the cell. Spindle fibers from the centrosomes connect to the chromosomes.
Anaphase -I: Spindle fibers contract and split the homologous chromosomes, moving them to opposite poles of the cell.
Telophase -I: Chromosomes decondense; cell divides to form two haploid cells.
1.2 Meiosis II
The second division: separates sister chromatids (these chromatids may not be identical due to crossing over in prophase I)
Prophase II: Chromosomes condense, nuclear membrane dissolves, centrosomes move to opposite poles (perpendicular to before)
Metaphase-II: the chromosomes align in the middle of the cell. Spindle fibers from the centrosomes connect to the chromosomes (at the centromere)
Anaphase-II: Spindle fibers contract and split the sister chromatids, and moves them to opposite poles of the cell.
Telophase-II: Chromosomes decondense,cells divides again to form another 2 haploid daughter cells. Final: 4 new cells.
2. The differences:
Mitosis:
- has 1 division per cycle
- one cell produces 2 new cells
- the genetic information in the mother-cell and the daughter-cells are the same. ( the number of chromosomes is also the same)
- it occurs in somatic cells
Meiosis:
- two divisions per cycle
- one cell when divides produces 4 new cells
- the new cells have different genetic information. mixes the genetic material from the parent cells
- the number of chromosomes of the daughter cells is half of the mother's.
3. Prokaryotic organisms don't divide through mitosis, they use a different process called binary fission. Only eukaryotic organisms, or those whose cells have a defined nuclei, undergo mitosis. Bacteria, for example, are prokaryotic organisms that use binary fission.
4.
It can't occur. Cross over is the exchange of DNA between homologous chromosomes. That will result in recombinant chromosomes during sexual reproduction. It can't occur on different chromosomes because they don't code for the same genes.
5. There are a lot of different theories about that, but it's mostly believed that meiosis must evolve before sexual reproduction. That's because The cell replicates their information first and then divides. Plus the cell does that even though it didn't recombine DNA with another organism (sexual reproduction).
Answer:
The elemental is required in very small amount. (Ans. A)
Explanation:
Trace element is also known as micro-nutrient. It is also defined as any chemical element required by living organisms in a minute or small amounts which is usually part of the vital enzyme (cells produced by catalytic protein).
Exact needs of trace elements vary among species, like commonly required plant trace elements are cooper, zinc, manganese, boron, and molybdenum. Animals commonly required iodine, manganese, and cobalt.
Absence of necessary plant trace elements required by plants in the soil causes deficiency disease, lack of animal trace elements used by animals in the soil may not harm plants, but, animals feeding on those plants develop their deficiency disease.
So, the adjective trace means that the elemental is required in a very small amount.
Answer:
D. a higher number of double bonds between carbon atoms in their structures.
Explanation:
