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3 years ago

Describe the characteristic of the endoplasmic reticulum

Biology

2 answers:

STALIN [3.7K]3 years ago

5 0

Answer:

The general structure of the endoplasmic reticulum is a network of membranes called cisterns, these bag-like structures are stretched together by the cytoskeleton. The phospholipid membrane surrounds the cystic space (or lumen), which is an extension of the nuclear space but is separated from the cytosol

gizmo_the_mogwai [7]3 years ago

5 0

Their passageways carry proteins and other materials from one part of the cell to another.

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What type of energy is often referred to as "energy of position"?

olasank [31]

Answer:

potential energy

Explanation:

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8 0

3 years ago

How do guard cells maintain homeostasis?

Mice21 [21]

Answer:

Explanation: Guard cells in the plants prevent water loss from it in cases of soil dryness or high temperature by closing themselves. If this does not happen, water will keep leaving the plant by the process of transpiration in these harsh conditions and the plant will not have the important medium for the homeostasis process to continue.

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2 years ago

Why choose that gene for PCR in the bacterial identification lab?

Reika [66]

Answer:

Background

During the course of a bacterial infection, the rapid identification of the causative agent(s) is necessary for the determination of effective treatment options. We have developed a method based on a modified broad-range PCR and an oligonucleotide microarray for the simultaneous detection and identification of 12 bacterial pathogens at the species level. The broad-range PCR primer mixture was designed using conserved regions of the bacterial topoisomerase genes gyrB and parE. The primer design allowed the use of a novel DNA amplification method, which produced labeled, single-stranded DNA suitable for microarray hybridization. The probes on the microarray were designed from the alignments of species- or genus-specific variable regions of the gyrB and parE genes flanked by the primers. We included mecA-specific primers and probes in the same assay to indicate the presence of methicillin resistance in the bacterial species. The feasibility of this assay in routine diagnostic testing was evaluated using 146 blood culture positive and 40 blood culture negative samples.

Explanation:

Results

Comparison of our results with those of a conventional culture-based method revealed a sensitivity of 96% (initial sensitivity of 82%) and specificity of 98%. Furthermore, only one cross-reaction was observed upon investigating 102 culture isolates from 70 untargeted bacteria. The total assay time was only three hours, including the time required for the DNA extraction, PCR and microarray steps in sequence.

3 0

3 years ago

What rocks will likely weather the least

Montano1993 [528]

Answer:

Rocks are in dry climate

Explanation:

Several types of rock , like granite, are very repellent to weathering. Moreover, igneous rocks serve to heat slowly because it is difficult for water to penetrate into them.

6 0

3 years ago

Classify the following characteristics depending on if they describe events occurring in mitosis, meiosis I, or meiosis II.

Temka [501]

Answer:

Mitosis events are:

Results in 2 genetically identical

diploid nuclei

A diploid number of sister

chromatids align at the spindle

equator during metaphase

Meiosis I events are:

Results in 2 genetically diverse

haploid nuclei

Homologous chromosomes align

at the spindle equator during

metaphase

Homologous chromosomes pair

up during prophase

Crossing-over occurs during

synapsis

Meiosis II events are:

Results in 4 genetically diverse

haploid nuclei

A haploid number of homologous

chromosomes align at the spindle

equator during metaphase

Explanation:

Mitosis is a type of cell division which produces two daughter cells that are genetically identical to the parent cell. In mitosis, the chromosome number of the parent cell is maintained in the daughter cells i.e. a diploid cell (2n) will undergo mitosis to produce two diploid (2n) daughter cells. During mitotic division, sister chromatids (replicated chromosomes) are involved in the division stages. i.e. diploid sister chromatids align at the equator of the cell during Metaphase and also sister chromatids are separated or pulled apart to opposite poles during Anaphase.

Meiosis, on the other hand, is a kind of cell division that results in daughter cells with a reduced number of chromosome (by half). Since the chromosome number is reduced, meiosis occurs in a two step division process viz: Meiosis I and II.

Meiosis I produces two genetically different daughter cells. The daughter cells have a reduced number of chromosomes i.e. from diploid (2n) to haploid (n). Meiosis I involves homologous chromosomes (similar but non-identical chromosomes received from each parent) which pair up to form a TETRAD structure in the Prophase stage. This structure allows for an exchange of chromosomal segment between non-sister chromatids of homologous chromosomes, a process called CROSSING-OVER. Crossing-over is what makes the daughter cells genetically different from the parent cell. Homologous chromosomes also aligns at the equator of the cell during Metaphase and later separates during Anaphase.

Meiosis II divides the two daughter cells produced in meiosis I into four genetically different daughter cells. Since the chromosome number has been reduced from diploid (2n) to haploid (n) in meiosis I when homologous chromosomes separate, haploid sister chromatids are involved in the stages of meiosis II i.e. haploid sister chromatids align at the equator of the cell during Metaphase and eventually becomes pulled apart during Anaphase.

5 0

2 years ago