Answer:
The correct answer is option B, that is, promoter, operator, gene.
Explanation:
In a prokaryote, just in front of the operator, the promoter is located, and just in front of the structural genes, the operator is located. All these in combination give rise to an operon.
Any gene, which codes for an enzyme or a structural protein is termed as a structural gene, in the lac operon, a structural gene codes for three distinct kinds of enzymes. A short sequence of DNA is situated just in front of the structural gene, which is known as the operator. An operator functions as a switch for transcription, that is, it monitors whether the process of transcription will take place or not.
Just in front of an operator, a sequence of a promoter is present, and for the transcription and translation of all the structural genes, the RNA polymerase needs to combine first with the promoter. In case, if no transcription is to take place, then the operator allows the repressor to bind with it and prevent the attachment of RNA polymerase with the promoter. Hence, the correct sequence of a prokaryotic operon is a promoter, operator, and gene.
Answer:
Green algae is divided into chlorophyte and chlorophyte. It possess chlorophyll a and b.
Bryophytes includes the liverworts, mosses and hornworts. It is know tracheaophytes I.e. is not vascular without extensive transport system, it needs water to reproduce sexually. It's Gametophyte is dominant and stomata are absent. (Hornworts possess stomata; it's related to tracheaophytes.
Ferns have vascular tissue, xylem and pholem, stem, root, leaves, dominant sporophyte. It's sporophyte possess rhizomes and fronds plus sporingia aldo called sori. Ferns are seedless vascular plants.
Gymnosperms includes the conifers, cycad e.t.c. It has its ovules resting on a scale. The ovules later develop into the seed. These seeds are naked as there are not enclosed in the chambers.
Angiosperms have flowers and fruits and show diuble fertilization. This is a huge clade that consists of all flowering plants. Unlike Gymnosperms
They develop enclosed in chambers known as ovaries.
Myofibrils are the building blocks or contractile unit of each muscle fiber. The tiniest functional unit of skeletal muscle, the sarcomere, is found in the myofibrils and is made up of protein filaments: actin (thin) and myosin (thick).
Answer:
The correct answer will be option- synaptonemal complex.
Explanation:
The tetrad arrangement of the genetic material in an organism is mediated by a highly conserved structure known as the synaptonemal complex. The synaptonemal complex is formed during the prophase I of the meiosis I which attaches the chromatin of the homologous chromosomes.
The synaptonemal complex is a proteinaceous structure which is formed by the two lateral ladders like elements with a central portion composed of the central element. The chromatin gets attached to the lateral elements while the central a portion bridge space between the two ladders thus help in the formation of the tetrad.
Thus, option- synaptonemal complex is the correct answer.
Flatworm<span>, also called platyhelminth, any of the phylum Platyhelminthes, a group of soft-bodied, usually much flattened invertebrates. A number of </span>flatworm<span> species are free-living, but about 80 percent of all </span>flatworms<span> are parasitic—i.e., living on or in another organism and securing nourishment from it.</span>
