Answer:
d. Hemoglobin helps maintain a constant pH in the blood by binding with H⁺ions released from bicarbonate ions.
Explanation:
The presence (CO₂) in in the erythrocytes lowers its pH as a result the affinity of hemoglobin decreases for oxygen. The carbon dioxide (CO₂) reacts with water to form carbonic acid in the presence of the enzyme carbonic anhydrase which is present in the erythrocytes or red blood cells. The carbonic acid then changes into two ions hydrogen ion (H⁺) and bicarbonate ion (HCO₃⁻). As a result of H⁺ ions, the pH of blood drops. Haemoglobin pick up hydrogen ions to balance the decrease in pH. Thus, haemoglobin helps in maintaining constant pH or keep pH of blood in buffer.
Answer:
The correct option is A, since if the DNA enters in a circular form it is called a plasmid, and the plasmids upon entering the bacteria self-replicate outside the genetic structure, which gives the bacteria better survival qualities.
Explanation:
Plasmids are generally circular extrachromosomal DNA molecules that replicate and transmit independently of chromosomal DNA, and are normally present in bacteria, archaea, and sometimes in eukaryotic organisms such as yeast. Its size varies from 3 to 10 kb. The number of plasmids can vary, depending on their type, from a single copy to a few hundred per cell. Plasmid vectors allow cloning of exogenous DNA ligands of up to 4 kb since a larger size than this makes cloning in these vectors difficult. The term plasmid was first introduced by the American molecular biologist Joshua Lederberg in 1952. Plasmids can only coexist as one or more copies in each bacterium, due to cell division they can be lost in one of the secreted bacteria.
Erythrocytes, neurons, skeletal cells, and columnar cells are examples of: specialized cells.
Cancer is an abnormal and uncontrolled multiplication of cells.
<span>Cancer also involves abnormal cell growth with the potential to spread to other parts of the body via blood and to form metastasis. Cancer cells avoid apoptosis (programmed cell death), have the limitless number of cell divisions and promote blood vessel construction. There are more than 100 types of cancers that affect humans with different signs and symptoms and with many different causes. </span>
