Answer:
The correct answer will be-
1. Nucleosomes
2. Chromatin
3. Sister chroamtid
4. Centromere
Explanation:
The DNA is a very long molecule which if has to be passed on to the daughter cell as it is will cause problems. So, to reduce problems a cell form tightly packed structure of DNA so that they can be passed easily to the daughter cell.
The packaging of DNA begins with the wrapping of the DNA around histone proteins which forms the 11 nm basic structural units called nucleosomes. The nucleosomes start condensing each other and form 30 nm structure chromatin fibres.
The chromatin fibres undergo replication during S phase which produces an exact copy of the chromatin called sister chromatids bound to each other at a central point called centromere which helps the separation of the chromatids during M phase.
Answer:
The ability of caffeine to inhibit adenosine receptors, plays a very important role in heightened alertness and sleeplessness.
Explanation:
"<em><u>Caffeine</u></em>" (<em>1,3,7-trimethylxanthine</em>) is an alkaloid obtained from plants. It has a chemical formula of C8H10N4O2.
Caffeine is generally <em>hydrophillic</em> but sufficiently <em>lipophilic</em> to pass through all biological membranes and readily cross the blood-brain barrier.
Therefore can bind with the adenosine receptors. Due to the blocking of adenosine inhibitory effects through its receptors held by paraxanthine and caffeine, it indirectly affects the release of <u>norepinephrine, dopamine, acetylcholine, serotonin, glutamate</u> e.t.c.
The release of the above-mentioned hormones have a great impact on the heightened alertness of the body, especially <em>dopamine</em> and <em>serotonin</em>.
Answer:
Animal clade
Explanation:
<em>A clade is used to refer to all members of group of organisms that share the same ancestor.</em>
Animals are the only group of living organisms that are eukaryotic, multicellular as well as heterotrophic in nature.
They are eukaryotic because their cells have nucleus and membrane-bound organelles like mitochondrion and chloroplast.
They are multicellular because their bodies are made up of more than one cells. The simplest animal (sponge) is made up of several cells while the most complex animal (human) is made up of millions of cells.
Animals are heterotrophs because they lack the capacity to manufacture their own food. They depend on external source for their food. Particular, animals ingest their foods, digest it internally and egest undigested food/waste materials.
D,record observations and measurements.
