Answer and Explanation:
Chemotaxis occurs when an organism moves toward a certain direction in response to a chemical.
Pollen is essential for the reproduction of plants because it produces a pollen tube that moves the sperm cells to the ovules that are located in the interior part of the flower. The pollen grains, produced in the anthers of a plant, <u>contain the male sex cells that will be transferred</u>. Chemotaxis plays a central role as it is a process in which chemical extracellular signals enable the movement of the pollen grains that will eventually enable plant reproduction.
Answer:
Thymine is used in replication while uracil is used in transcription.
Explanation:
<em>New cells can only be created after transcription has taken place. Replication results in mRNA strands while transcription creates new DNA. Transcription happens outside the nucleus and replication happens inside the nucleus. Thymine is used in replication while uracil is used in transcription.</em>
DNA replication is a process whereby DNA makes a copy of itself while DNA transcription is a process whereby a messenger RNA is synthesized from a DNA strand.
Both processes involve the building-up of nucleotides or purine.pyrimidine bases. Replication involves building up of cytosine, guanines, adenine, and thymine bases while in transcription, the thymine base is replaced by uracil base.
Hence, the correct answer is that <u>Thymine is used in replication while uracil is used in transcription.</u>
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Light alerts the biological clock to slow down the secretion of melatonin hormone that promotes sleep. Melatonin hormone is a hormone that is produced by the pineal gland in animals and regulates sleep and wakefulness. . The hormone is used to regulate night and day cycles or sleep-wake cycles, darkness causes the body to produce more melatonin, which signals the body to prepare for sleep. Light decreases melatonin production and signals the body to prepare being awake.
Is there any options to choose from? multiple choice or do you have to write it yourself?
Therefore "the copperheads are subspecies and the cottonmouth is a separate species".
<u>Answer:</u> Option C
<u>Explanation:</u>
The higher classification is "copperhead" for both the subspecies Agkistrodon contortrix contortrix and Agkistrodon contortrix mokasen. As the name itself consist species name "A. contortrix", both are belonging from "Viperidae" family, "Crotalinae" subfamily and venomous pit viper subspecies.
These are generally silent snakes as they show lazy and motionless behavior when encountered but on agitating sufficiently they become protectively aggressive and they are species of eastern North America. While Agkistrodon piscivorous are separate species with higher classification as "Cottonmouth" and name carry species name "A. piscivorus". It is indigenous to southeastern United States and belongs to same family as copperhead.