Answer:
B
Explanation:
Ferns are in the group pteridophytes. These plants have a vascular system – which also means they have true roots, stem, and leaves-, however, they produce through spores (not seeds like higher plants-gymnosperms and angiosperms). Other than ferns, other plants in the group are horsetails and club-mosses. Unlike in higher plants, where the gametophyte is the dominant phase of the life cycle, the sporophyte is the dominant phase in pteridophytes and other lower plants.
Answer:
21
Explanation:
Amino acids are the basic structural units of proteins. Our bodies contain 21 amino acids it uses to make all proteins, although books recognize only 20 amino acids. The 20 amino acids are the alphabet of proteins.
Answer:
This question lacks options, the options are:
A. They may act to turn on gene transcription.
B. They may act to turn off gene transcription.
C. They may become added to DNA, and then be transcribed.
D. They may remove a gene from DNA.
E. They may alter the nucleotide sequence in a gene.
Options A and B are the answers.
Explanation:
Prokaryotes regulate gene expression at the transcriptional level. Gene expression is the process whereby living organisms synthesize useful products such as protein from a gene. Prokaryotes such as bacteria control the expression of their genes via proteins that bind to DNA called REGULATORY PROTEINS.
These regulatory proteins also known as TRANSCRIPTION FACTORS, act to regulate genes by binding DNA. The binding of DNA either prevents or promote the binding of RNA polymerase in order for transcription to occur.
- Regulatory proteins which may act to inhibit transcription of DNA by turning off gene are called REPRESSORS.
- Regulatory proteins which may act to promote transcription of DNA by turning on gene are called ACTIVATORS.
(1) through the spinal nerves that attach to it, the spinal cord is involved in the sensory and motor innervation of the entire body<span> inferior to the head; (2) through the ascending and descending tracts traveling within its white matter, the spinal cord provides a </span>two-way conduction pathway<span> for signals between the body and brain; (3) through sensory and motor integration in its gray matter, the spinal cord is a </span><span>major center for reflexes</span>
Answer:
True.
Explanation:
Rotenone is a broad spectrum pesticide and insecticide and is also considered as a non-selective piscicide.
The action mechanism of the rotenone has been described below -
It interferes with the electron transport chain which occurs in mitochondria of the cells. Here the transfer of electrons from complex I to the ubiquinone is inhibited by the rotenone. As a result, ATP formation with the help of NADH is also inhibited. When electron transport fails, oxygen in the cell is reduced to oxygen radical which further damages DNA and other components present in the mitochondria.