Answer:
True
Explanation:
Chiasma is the site of crossing over. It is an X-shaped site that appears in a tetrad (bivalent) chromosome during the diplotene stage of prophase I of meiosis I. Crossing over refers to the exchange of segments of chromatids and occurs between homologous chromosomes only. Crossing over is the event of prophase I of meiosis I and produce new gene combinations.
The homologous chromosomes are separated from each other but remain attached at chiasmata. The dissolution of chiasmata occurs by the end of prophase I and separates the homologous chromosomes completely from each other. Crossing over does not occur in mitosis. Since mitosis does not include crossing over, chiasmata are also not formed in mitosis.
Answer:
Explanation:
The correct answer is (B) Helicase creates the replication fork; single-strand binding proteins keep the single strands from reuniting. The replication fork is established by the enzyme DNA helicase, which separates the two complementary strands of a DNA molecule
Answer:
Energy that is not used in an ecosystem is eventually lost as heat. Energy and nutrients are passed around through the food chain, when one organism eats another organism. In each case, energy is passed on from one trophic level to the next trophic level and each time some energy is lost as heat into the environment.
Explanation:
Answer:
No
Explanation:
Both A alleles and B alleles are dominant over the O alleles. This means that both parents must have an O allele present to even have a chance of having a child with type O blood. Lets say the mother has type O blood with the father having type AB blood. The possible combination would be: AO, BO, AO, BO. The punnett square should look like this:
A B
O AO BO
O AO BO
Answer:
A. looking for ways to improve the quality of water
