Cell organelles

Rna processing drag the correct labels under the diagrams to identify the events of rna processing.

Elena-2011 [213]

In the beginning of the RNA strand as a cap, a modified guanine nucleotide is added. After this, there is a removal of those segments of the RNA strand that do not actually code for the protein. And those RNA’s segments that do code for the protein are reconnected. And forking a tail, extra adenine nucleotides are added to the end of the RNA strand. The mRNA or messenger RNA which is already completed will then leave the nucleus. This whole process is called the RNA processing. Before the RNA copy of a protein encoding can be transported out of the nucleus and translated into protein, it must be first be modified in several ways. A precursor of mRNA, pre-mRNA is the primary transcription product of a gene.

3 0

4 years ago

Is the temperature profile in the thermosphere more like that of the troposphere or the stratosphere?

podryga [215]

The correct answer is: stratosphere.

This is because their temperatures are rising instead of decreasing.

There are 4 primary layers of the atmosphere on Earth:

Troposphere (6-20km), the layer that we live in, where the weather occurs. Only nitrogen and oxygen present.

Stratosphere (20-50 km), where the airplanes fly, contains the ozone layer, which absorbs harmful radiation from the sun.

Mesosphere (50-85 km), the coldest region of Earth’s atmosphere (-100 C), protective layer

Thermosphere (80-690), the hottest (1500 C) and the thickest layer which consists of the ionosphere and the exosphere.

5 0

3 years ago

Bruce Wallace (1963) established a laboratory population in which the recessive allele lt was at a frequency of 0.5. He propagat

Alenkinab [10]

Answer:

a. True

Explanation:

Bruce Wallace was a professor emeritus of genetics who performed many population studies. He worked in 1958 at the University of Cornell as a professor of genetics. In 1963, he performed a population study wherein the recessive allele It was at a frequency of 0.5. The population was propagated for 10 generations and the frequency of It for each generation was determined.

The result of this study showed that lt/lt died without reproducing, whereas, individuals with genotype +/+ were normal.

8 0

3 years ago

Predict phenotypes associated with nondisjunction of sex chromosomes.

Mnenie [13.5K]

Answer: The new daughter cells will have an abnormal amount of genetic material. That is called aneuploidy and it is the presence of an abnormal number of chromosomes. Different clinical conditions are the result of this nondisjunction.

Explanation:

Normal cells are diploids, that means they have two copies of each gene, one of each chromosome. So normal cells have two homologous chromosomes, one from each parent.

During anaphase of cell division, each pair of chromosomes is separated by the mitotic spindle. The separated chromosomes are then pulled by the spindle to opposite poles of the cell, and eventually will end up in the new daughter cells.

Nondisjunction is the failure of homologous chromosomes to separate properly during cell division, so it is the miss segregation of them. The new daughter cells will have an abnormal amount of genetic material. Different clinical conditions are the result of this nondisjunction.

Sex chromosomes participates in sex determination of an individual. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY) So nondisjunction of sex chromosomes could be:

XX: one cell with no chromosome and the other cell with two X chromosomes.
XY: one cell with no chromosomes and the other cell with XY chromosomes.

According to which gametes are fused during fertilization, different phenotypes can be given. For example, if a gamete with one chromosome fuses with another gamete with two chromosomes, the result will be an individual with three chromosomes (it could be XXY, or XXX) called trisomy.

Triple X syndrome is characterized by an extra X chromosome in females. Those affected are often taller than average, but most females have a normal sexual development. Klinefelter syndrome is known XXY individuals, and it causes infertility in males, breast growth, less body hair and weaker muscles.

And if a gamete with no chromosome fuses also with another gamete with no chromosome, the result is a nullisomy. But due to the lack of genetic material, the nullisomic gametes are rendered unviable for fertilization.

And if a gamete with no chromosome fuses with another gamete with one chromosome (normal) the result is a monosomy, the presence of only one chromosome from a pair. The result can be an individual who is X or Y. People with Turner syndrome have one X chromosome and it is the only monosomy that is seen in humans because other cases monosomy are lethal.

Any of those examples is called aneuploidy and it is the presence of an abnormal number of chromosomes.

3 0

3 years ago

1

Arada [10]

Answer:

Ο Α.

Sensory receptors in the skin detect the stimuli from the environment.

Explanation:

Simple process of elimination. Keratin is what makes up hair and nails. Muscles cannot detect temperature change, and connective tissue can't either. The sensory receptors that detect heat and cold are called thermoreceptors

5 0

3 years ago

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