Answer:
Density is conserved in chemical reactions and shown by balanced equations
DNA is the main type of genetic material found in a cell. In addition,
it is found in the nucleus of the cell, so (D) is correct. DNA in the
nucleus is used in replication (through mitosis and meiosis) via
daughter cells to continue cell growth.
Natural selection is when certain environmental qualities cause a species to evolve in order to survive in the environment. Natural selection is a specific part of that, when some of the variations of the species die off because they can't survive, then the ones who survive live to create more living babies with the qualities that allow them to survive in the environment.
Vestigal structures is the answer!!
The correct order of expression of the genes listed below in the determination of segmentation in Drosophila is "Hox genes > Gap genes > Pair rule genes > Segment polarity genes"
<u>Order: </u>2 > 3 > 4 > 1
<u>Explanation:</u>
The master regulator genes are that guide the creation of specific body segments or structures known as "Homeotic genes". Since these genes are active in segment patterning, the gap genes, pair-rule genes and segment polarity genes are designated as segmentation genes.
- Many animal homotic genes express transcription factor proteins that include a region called the homeodomain or Hox gene.
- The maternal impact genes express transcription factors which regulate the gap gene expression. The distance genes subdivide the embryo approximately along the anterior / posterior axis.
- The gap genes encode transcription factors which control the pair-rule expression of genes. The pair-regulated genes split the embryo into segment pairs.
- The pair-rule genes encode transcription factors which control the function of the polarity genes in the segment. The polarity genes in the segment determined each segment's anterior or posterior axis.
