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4 years ago

Microevolution _____.

Biology

2 answers:

olga55 [171]4 years ago

6 0

I think that the answer is "Refers to evolution at or below the species level.

yaroslaw [1]4 years ago

5 0

Microevolution refers to evolution at or below the species level.

Microevolution is the change in gene frequency that takes place over time within a species or population. Microevolution is usually observed over a relatively short amount of time and it occurs as a result of four different processes which include gene flow, genetic drift, selection (natural and artificial), and mutation.

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What is the relationship among chromosomes, genes, and DNA? a. Genes read the DNA code found on chromosomes. Chromosomes are lon

EastWind [94]

Answer:B

Explanation: because gene are made up of DNA and are the one which made Chromosome and allocated at point called locus

7 0

3 years ago

The first trilobites found in China were discovered in a layer of rock called the Devonian Shale. If you were hunting for trilob

olasank [31]

Answer:

Rocks which were underwater long time ago.

Explanation:

If we were hunting for trilobites in Canada, we look for those types of rocks where once water present on it because trilobites are the organisms which lived in the marine ecosystem so if they are present in marine so we have to look those rocks which were underwater millions of years ago. Trilobites are the extinct marine arthropods that were present around 521 million years ago.

6 0

3 years ago

What proportion of DNA molecules will contain any radioactivity after two rounds of replication?

Vladimir [108]

Answer: After two rounds of replication half of DNA molecules will contain one strand with radioactive nitrogen. And the other half will contain two strands with radioactive nitrogen.

Explanation:

In semi-conservative replication, two DNA molecules are created, each consisting of one strand of the original DNA and one new complementary strand. In other words, the DNA is formed from one old strand and one new strand. And the existing strands serve as a complementary mould to the new ones.

Meselson-Stahl's experiment involves growing the bacterium Escherichia coli in a medium containing radioactive nitrogen. Watson and Crick had predicted that DNA replication was semi-conservative, if so the DNA extracted from the bacteria would be somewhere in between the DNA extracted from the "normal" nitrogen medium and the radioactive nitrogen medium.

DNA replication, which occurs only once in each cell generation, requires many "building blocks", enzymes, and a great deal of energy in the form of ATP. The nucleotides, which are the building blocks of DNA, have to be assembled and available in the nucleus along with the energy to bind them together. Each nucleotide consists of three parts: a nitrogen-containing ring structure called a nitrogen base, a five-carbon sugar, and at least one phosphate group.

Through the action of DNA polymerase during replication, new nucleotides bind to the corresponding nucleotide of the original chain (A to T, C to G).

Since the DNA strands are anti-parallel, and replication proceeds only in the 5' to 3' direction on both strands, one strand will form a continuous copy, while the other will form a series of short fragments known as Okazaki fragments. The chain that is synthesized continuously is known as the forward chain and the chain that is synthesized in fragments is known as the backward chain.

Then, since replication is semi-conservative, the new strand will have nucleotides with "normal" nitrogen while the new strand created from that same DNA molecule will incorporate nucleotides with radioactive nitrogen. So, after two rounds of replication half of DNA molecules will contain one strand with radioactive nitrogen. And the other half will contain two strands with radioactive nitrogen.

7 0

3 years ago

What do scientists use to describe the climate of an area?

kupik [55]

Answer:

Explanation:

Though the wildlife is based on the weather (you wouldn't see a polar bear in the rainforest), the weather is not based on the wildlife. If you put a polar bear in the rainforest, it won't make it a tundra. The ages of the plants are also completely irrelevant.

4 0

3 years ago

If two traits among flowers, dwarfism and stem color, were on the same pair of chromosomes, would you expect an F2 generation of

sammy [17]

Answer:

Yes, there will still be a chance for the F2 generation to have a ratio 9:3:3:1

Explanation:

According to Mendel's law of segregation, alleles of a gene pair separate at the time of game formation.

According to the Law of independence, the alleles sort independently into the gametes.

Even if the two traits under study are located on the same chromosome, they will segregate and assort independently at the time of gamete formation.

Also, at the time of meiosis, one of the alleles will arise from each parent hence there will still be a chance for the F2 generation to have a 9:3:3:1 ratio.

6 0

4 years ago