Answer:
The five categories of vertebral column are:
- Cervical
- Thoracic
- Lumbar
- sacrum
- coccyx.
Explanation:
The 26 vertebrae of the spine or vertebral column are classified into five categories based on the structural differences between them. The first category is cervical and is made of seven cervical vertebrae. The spines of cervical vertebrae are shorter than that of others and have bifurcations.
The next category is the thoracic and is made of twelve thoracic vertebrae. Thoracic vertebrae are followed by lumbar region made up of 5 lumbar vertebrae. Spines of thoracic vertebrae are longer and are directed downwards while that of the lumbar vertebrae project towards the posterior region. the sacrum is present below the lumbar region and consists of five fused sacral vertebrae. The last category of spine is coccyx. It has four fused coccygeal vertebrae.
Answer:
Seeds and fruits are formed by fertilization. In angiosperms, two structures are formed as a result of double fertilization – a diploid zygote and a triploid primary endosperm cell. The zygote develops into an embryo, whereas, the endosperm cell gives rise to endosperm. It provides nourishment to the growing embryo. Both fruits and seeds are an important part of angiosperms...
Hope it helps XD...
Answer:
1- Test tube with DNA sample is placed in machine
2- DNA sample is heated
3- DNA denatures
4- Taq polymerase initiates DNA synthesis
5- Double-stranded DNA is produced
Explanation:
The Polymerase Chain Reaction (PCR) is a technique widely used in molecular biology laboratories in order to produce many copies of a specific DNA sample. Thermocyclers are machines designed for a cyclic temperature change of the PCR. First, an initial denaturation step where DNA sample is heated to separate the double-stranded DNA into two single strands. Subsequently, 20-40 PCR cycles are repeated to produce millions of copies of a specific DNA sequence. There are three steps in each PCR cycle: 1-Denaturation to 94–98 °C (DNA strands are separated), 2-Annealing to 50–67 °C (primers bind to each DNA strand on the opposite ends of the DNA strands to be copied) and 3-Extension to 75–80 °C (Taq polymerase initiates the synthesis of complementary DNA strands).
