Answer
When a eukaryotic cell is not undergoing mitosis, the DNA and its associated proteins appear as a visible network of dark fibers called the Chromatin.
Definition
Chromatin is a thread like structure that can be seen inside nucleus before cell division. It is a complex of DNA and histone proteins.
Forms of chromatin
Chromatin exist in two forms, that is
a. Euchromatin
It is less condensed and can be easily transcribed.
b. Heterochromatin
It is highly condensed and not transcribed as easy.
Organization of chromatin
Microscopy has shown the appearance of chromatin as beads on a string. The beads are called nucleosomes.
Nucleosome
Each nucleosome is composed of DNA wrapped around eight histone proteins. The nucleosome is then wrapped into a 30nm spiral called solenoid.
Answer:
D
Explanation:
Facilitated diffusion is a form of passive transport hence no energy is required by the cell. This means that while the molecules are moving down a concentration gradient – line normal diffusion – the movement of the molecules needs to be facilitated (in this case by a transmembrane protein) either because the molecule is polar and can't pass through the hydrophobic region of the cell membrane, or the molecule is too big to passively pass through the small natural pores of the cell membrane.
This question is incomplete because the options are missing; here is the missing section:
Which would most likely be found in his paper?
A. A review of modern human anatomical structure.
B. Evidence of changing environmental conditions, with references.
C. The reasons competing hypotheses are wrong.
D. His opinion of what will happen to the survival of the human race.
The answer to this question is B. Evidence of changing environmental conditions, with references.
Explanation:
In texts such as scientific articles, the central point is expressed by the main claim or hypothesis as this is supported and explained through evidence in the articles. This means Potts article focuses on the environmental changes and how these contributed to the human species adaptability.
Due to this, it is expected the article explains the changes in environmental conditions, and the connection of these to adaptability. Moreover, because this is a scientific article all ideas should be supported with evidence collected by the author including references to other reliable sources. Thus, "evidence of changing environmental conditions, with references" is expected to be found in this article.
<em>Water has unique chemical characteristics in all three states—solid, liquid, and gas—thanks to the ability of its molecules to hydrogen bond with one another. Since living things, from human beings to bacteria, have a high water content, understanding the unique chemical features of water in its three states is key to biology.
</em>
<em>In liquid water, hydrogen bonds are constantly being formed and broken as the water molecules slide past each other. The breaking of these bonds is caused by the energy of motion (kinetic energy) of the water molecules due to the heat contained in the system.
</em>
<em>When the heat is raised (for instance, as water is boiled), the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas. We observe this gas as water vapor or steam.
</em>
<em>On the other hand, when the temperature drops and water freezes, water molecules form a crystal structure maintained by hydrogen bonding (as there is too little heat energy left to break the hydrogen bonds). This structure makes ice less dense than liquid water.</em>
This rock can be classified as:
an igneous rock.
Igneous rocks are made up of
randomly arranged interlocking crystals and the important minerals that can be
found in igneous rocks are feldspars, quartz, olivines, pyroxenes, amphiboles,
and mafic minerals. All of these minerals are important in the formation of
almost all igneous rocks, and they are basic to their classification.
