Answer:
according to me the answer is abiotic factor
Answer:
In metaphase 1, chromosomes from the mother and father line up randomly along the middle of the cell.
Explanation:
In diploid (2n) organisms, the homologous chromosomes are the two copies of each chromosome, where one of these homologs is the chromosome from the mother, while the second one is from the father. During metaphase I, the homologous pairs of chromosomes pair together at the middle of the cell. The law of independent assortment, also known as or Mendel's Second Law, states that homologous chromosomes line up in random orientations at the metaphase plate during this period (metaphase I).
the correct answer is A- Reproductive isolation occurred through behavioral isolation
A process of formation of a new species from an existing species is called speciation. New species may formed due to geographical or reproductive barriers which isolates the members of a population of a species to form a new species.
In the given question, speciation in In the leopard frogs occurred due to a particular or specific call given by males to the females. The courtship call lead to reproductive isolation due to change in behavior. Such type of behavioral change will help in recognizing mates of the same species and this will act as a reproductive barrier among the other related species.
Answer:
(A): DNA and protein
(B): The case for proteins appeared stronger until the 1940s, especially since biochemists had identified them as a class of macromolecules with great heterogeneity and function specificity, essential requirements for the hereditary material. Moreover, little was known about nucleic acids, the physical and chemical properties of which seemed far too uniform to account for the multitude of specific hereditary traits of each organism
(C): Virulent strains are pathogenic (causing disease), whereas non-virulent strains are non-pathogenic (harmless) strains.
Answer:
Because of homologous recombination
Explanation:
- When genes are establish on different DNAs or far apart on the same chromosome, they are classified self-sufficiently and are said to be unlinked.
- When genes are very close together on the same chromosome, they are said to be linked. That means that alleles, or genetic versions, that are already together on a chromosome will be inherited as a unit more often than not.
- We can see if two genes are linked, and how closely, by using data from genetic crosses to calculate the frequency of recombination.
- Using the technique of discovery recombination happenings for numerous gene pairs, we can make link maps that show the order and relative distances of the genes on the chromosome.
- When the genes are on the same chromosome but far apart, they are classified independently due to crossing (homologous recombination). This is a procedure that happens at the start of meiosis, in which homologous DNAs randomly exchange matching fragments. Crossing be able to connection new alleles in combination on the same chromosome, causing them to enter the same gamete. When the genes are far apart, the crossing occurs with sufficient frequency for all types of gametes to occur with 25% percentage frequency.
- When the genes are very close together on the same chromosome, the crossing still occurs, but the result (in terms of the types of gametes produced) is different. Instead of being classified independently, genes tend to "stay together" during meiosis. That is, alleles of genes that are already together on a chromosome will tend to pass as a unit to gametes. In this case, the genes are linked
