Biology Questions

Cellular respiration can be broken down into three main steps:

1. Glycolysis,

2. The Kreb's cycle (The citric acid cycle), and

3. Electron Transport Chain.

A chromatid is one copy of a newly copied chromosome which is still joined to the original chromosome by a single centromere.

The two identical copies—each forming one half of the replicated chromosome are called chromatids.

Chromonema is the fibre-like structure in prophase in the primary stage of DNA condensation. In metaphase, they are called chromatids.

A RNA copy of a DNA gene is called as messenger RNA or mRNA. mRna is used in translation because information is translated from one language (nucleotides) into another (amino acids).

Hence, mRNA is used to transfer genetic information by a cell.

The brain has three main parts the cerebrum, cerebellum and brainstem. As cerebrum is the largest part of the brain it is divided into two hemispheres i.e, right and left. It performs many functions like vision, hearing, touch, learning, consciousness, emotions, etc...

A reverse transcriptase (RT) is an enzyme used to generate complementary DNA (cDNA) from an RNA template by a process called Reverse Transcription.

In brief its function is that copies all or part of the virus RNA (retroviruses are RNA-only) as DNA which can then be integrated into the DNA of the host organism.

Asterias has bilateral symmetry only at larval stagebut fivefold symmetry (pentamerism, a special type of radial symmetry) as adults.

Nereis do not possess any symmetry elements in their body organisation.