Answer:
When cells split and increase they do this very important thing in order tonmake the new cells exactly the same as the previous before them. Each cell makes more of all it's genes. Then each one.splits into two with one group of genes in each one of the new cells. During the process they make sure that all are copied correctly.
Only animals in the same <u>species</u> can always breed and have fertile offspring.
Although animals in the same genus<em> can </em>breed, their offspring are usually infertile.
Answer:
1) c. five
2) a. lysine and arginine
3) g. two
4) d. four
Explanation:
A nucleotide can be defined as an organic molecule which forms the building block of nucleic acid such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
Basically, nucleotide comprises of the following parts;
1. Nitrogenous base: this includes adenine (A), thymine (T), guanine (G), and cytosine (C) which are mainly found in the DNA while adenine (A), guanine (G), uracil (U) and cytosine (C) are found in the RNA.
2. A phosphate group.
3. A penrose sugar: it is either deoxyribose in DNA or ribose in RNA.
The two parts or chemical components of a nucleotide which do not change throughout the structure of DNA are;
I. Five-Carbon Sugar also known as deoxyribose and it has hydrogen on its second carbon.
II. Phosphate: this is the structural backbone that provides support to DNA.
Histones are a group of highly basic proteins that are mainly associated with deoxyribonucleic acid (DNA) in the nucleus of a living organism and then condense it to chromatin.
Histones include five main classes of relatively small basic proteins containing relatively large amounts of lysine and arginine. Nucleosomes are made of two each of four types of histones.
Answer:
c. YACs
Explanation:
YACs, the Yeast artificial chromosomes are the high capacity vectors designed to carry the eukaryotic genes and carry the insert of 200-2000 kb.
YACs carry origin of replication from yeast, selectable markers and sequences derived from telomeres and centromere to maintain the stability of the insert during cell division.
The insert size for plasmids, bacteriophage, PACs, and cosmids is about 0.1-10 kb, 5-25 kb, 100-300 kb, 35-45 kb respectively.
The answer is b
<span>1.Upper Epidermis – The upper surface of a leaf that protects the inner cells of the leaf. 2.Palisade Layer – Long, thin, tightly-packed cells where most photosynthesis takes place. 3. Spongy Layer – Loosely packed cells with many air spaces between them in order to allow carbon dioxide to pass among the cells and get to the chloroplasts. 4. Lower Epidermis – The bottom layer that protects the underside of the leaf and has many openings (stomata)</span>
