Answer:
Sea anemones are marine predatory animals. They are like a terrestrial flowering plant due to their colorful appearance. They are coming under the phylum cnidaria.
Sea anemones are found in different forms called a polyp. It has a columnar trunk, on the top of the trunk an oral disc and centrally placed mouth. The mouth is surrounded by tentacles.
Sea anemones have a gastrovascular cavity that serves as stomach. This cavity has one opening both meant for mouth and anus.
Sea anemones are capable of changing their shape and lives on the mud, holding it by pedal disc.
Polychaetes are segmented worms. Each segment of the body bears parapodia. It helps them in locomotion. There are different types of polychaetes, tube-dwelling polychaetes are one of them.
Tube - dwelling polychaetes make tubes to protect their soft bodies.
They don't have parapodia but some special anterior structures for feeding. The tubes are made from calcareous materials.
Endemism
Endemism is the state of a species being native to a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere.
Explanation:
Endemic species are those that are found in just one region and nowhere else in the world. For example, kangaroos are originally endemic to Australia and are found nowhere else in the world. ... The Tasmanian Tiger is one such animal that was endemic to Australia, Tasmania and New Guinea. But now, it is extinct.
The correct answer is: b. It is free to bind to another promoter and begin transcription
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex.
RNA polymerase is also released and can transcribe some other gene by binding to its promotor. RNA polymerase will transcribe just the genes whose products are needed at a particular moment.
4. Gene frequencies will remain constant
Answer:
Una variable de control (o constante científica) en la experimentación científica es un elemento experimental que es constante y sin cambios durante el curso de la investigación. ... Las variables de control en sí mismas no son de interés primario para el experimentador.
Explanation:
