11)

(problem 8, part 2) describe what happens at the initiation stage of transcription.

Arte-miy333 [17]

Transcription proteins assemble at a hairpin loop formed by inverted repeats in the DNA template. RNA polymerase creates a nick in one of the DNA strands and begins to separate the nontemplate from the template.

3 0

3 years ago

which term describes this example? a rabbit's cells have two sex chromosomes that are different. A.homozygous dominant B.homozyg

solniwko [45]

Both answers C and D are correct, however, answer D makes more sense.

7 0

3 years ago

What would be the expected result if a competitive, nonhydrolyzable analog of ATP were applied to the cytoplasmic side of a plas

Yakvenalex [24]

Answer:

The cell interior would experience higher than normal Na+ concentrations and lower than normal K+ concentrations.

Explanation:

The Na/⁺K⁺ pump is an ATPase pump which is responsible for maintaining low Na⁺ and high K⁺ concentrations within the cytoplasm while maintaining high Na⁺ and low K⁺ concentrations in the extracellular fluid.

Since these two ions are moved against their concentration gradient, ATP hydrolysis is required to provide the energy for this process. This is done by moving in two K⁺ ions inside while moving three Na⁺ ions outside the cell for every molecule of ATP hydrolysed to ADP and Pi.

If a competitive non-hydrolyzable analog of ATP is applied on the cytoplasmic side of a plasma membrane that contained a large concentration of the Na/⁺K⁺ pump, it will act by inhibiting the action of the Na/⁺K⁺ pump. This will result in an accumulation of Na⁺ ions inside the cell and lower than normal K⁺ ions concentration.

6 0

2 years ago

Two different scientists were studying the carbon levels of the air above a large city. They both found that the levels had incr

ss7ja [257]

Answer:

Scientist 1

Explanation:

The conclusion of scientists 1 is valid.

Human activities such as burning of fossil fuels, agriculture, deforestation, etc. leads to the emission of carbon in the form of carbon dioxide into the atmosphere. An increase in the population of a city will only lead to an increase in these activities and hence, an increase in the amount of carbon emitted into the atmosphere.

Also, volcanic activities leads to the production of volcanic gases which is a mixture of carbon dioxide, oxides of sulfur, nitrogen, etc.

However, an active volcano that is several miles away from the city might not be a major source of carbon in the air above a large city. The carbon dioxide produced from such volcanic activity thins out before reaching the city.

5 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