explain why offspring of plants exposed to radiation may have characteristics not four in the original population

Meselson and Stahl used density labeling of DNA to show that DNA replication occurs via a semiconservative mechanism. In their e

cricket20 [7]

Answer:

The organism previously used 15N for replication so all the DNA molecules were of 15N15N type. Then the organism is shifted to a medium where only 14N is available for replication.
According to semi conservative mode of replication, a newly synthesised DNA molecule consists of one new strand and one parental strand. So after the first round of replication, All the 15N strands will synthesise new DNA strands using 14N resulting into intermediate 15N14N DNA molecules. Hence, only one band would be observed (15N14N) above the original 15N15N band since 15N14N has lighter isotope too so it will be lighter than 15N15N molecules and will lie above it.
After second round of replication, 15N strand from 15N14N would synthesise another 14N strand. 14N strand from 15N14N molecules will also synthesise another 14N strand. So now, 50% of the DNA molecules will be of 15N14N intermediate type and 50% of them will be of 14N14N type.Two bands will be observed above the original 15N15N band. One band of 15N14N molecules will be right above it and other band of 14N14N molecules will be even higher because it is the lightest band since it has only the lighter isotope of nitrogen.

8 0

3 years ago

You are observing different tissue samples and classifying the cells into their respective stage in the cell cycle. What can you

svp [43]

We have been given that different tissue samples are in their respective stage of cell cycle.

Ans is option B because cancerous cells tend to divide indefinitely regardless of the presence or absence of growth factors. In cancerous cells G0 check points fail and the cells are always in some stage of mitosis i.e. cell is supposed to be in any of the following stages of mitosis :

1) Prophase

2) Metaphase

3) Anaphase

4) Telophase

3 0

3 years ago

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Each chromosome in this homologous pair possesses a different allele for flower color. Which statement about this homologous pai

Stells [14]

Answer:

These homologous chromosomes represent a maternal and a paternal chromosome

Explanation:

3 0

3 years ago

Which adaptation makes bipedalism possible?

amid [387]

An adaptation that makes bipedalism possible is the need to get around. If your slithering on the ground, you could get diseases, or get hurt.

7 0

3 years ago

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We are trying to determine the possible modes of inheritance for some particular human disorder. We have a very small pedigree f

ziro4ka [17]

Answer:

Complete question:

We are trying to determine the possible modes of inheritance for some particular human disorder. We have a very small pedigree for this disorder. Assuming the pedigree is accurate, indicate which of the six modes of inheritance are consistent with this pedigree: Select one or more Y Linked Autosomal Recessive Autosomal Dominant X-Linked Dominant X-Linked Recessive We are trying to determine the possible modes of inheritance for some particular human disorder. We have a very small pedigree for this disorder, Assuming the pedigree is accurate, indicate which of the six modes of inheritance ere consistent with this pedigree Select one or more X-Linked Recessive Y Linked Autosomal Recessive X-Linked Dominant Autosomal Dominant.

Answer:

After the analysis of this pedigree, it is clears that the inheritance pattern is X linked because the offsprings are affected with parents genotgype

Explanation:

The inheritance is X linked dominant because of the presence of one dominant gene for the affected genotype in male.

The male individuals are affected. This is therefore not a recessive inheritance in later case, it is only when the two genes are present at the same time the affected genotype will be seen.

4 0

4 years ago