Free NTA Biology Question and Answers — Questions and Answers
Question 1: What is the basic unit of life?
- Atom
- Molecule
- Cell (Correct answer)
- Tissue
Correct answer: Cell
The cell is universally recognized as the fundamental structural and functional unit of all known living organisms. According to cell theory, all living things are composed of one or more cells, and all cells arise from pre-existing cells. It is the smallest entity that can carry out all the processes necessary for life.
Question 2: Which organelle is known as the powerhouse of the cell?
- Nucleus
- Ribosome
- Mitochondrion (Correct answer)
- Endoplasmic reticulum
Correct answer: Mitochondrion
Mitochondria are often referred to as the 'powerhouses of the cell' because they are responsible for generating most of the cell's supply of adenosine triphosphate (ATP). ATP is used as a source of chemical energy through the process of cellular respiration. This vital function fuels various cellular activities, from muscle contraction to nerve impulse transmission.
Question 3: What is the primary function of the ribosome?
- Energy production
- Protein synthesis (Correct answer)
- Cell division
- DNA replication
Correct answer: Protein synthesis
Ribosomes are essential cellular organelles responsible for protein synthesis, a process also known as translation. They read the genetic information encoded in messenger RNA (mRNA) and use it to assemble amino acids into specific protein chains. This function is crucial for all cellular activities and structures, as proteins perform a vast array of functions within the cell.
Question 4: Which process describes the division of a cell’s nucleus to produce two identical nuclei?
- Mitosis (Correct answer)
- Meiosis
- Cytokinesis
- Transcription
Correct answer: Mitosis
Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus. This process is crucial for growth, repair, and asexual reproduction in eukaryotic organisms, ensuring genetic identicalness between parent and daughter cells. Meiosis, in contrast, produces four genetically distinct haploid cells for sexual reproduction.
Question 5: What molecule carries genetic information from the nucleus to the cytoplasm?
- DNA
- RNA (Correct answer)
- Protein
- Carbohydrate
Correct answer: RNA
Ribonucleic acid (RNA), specifically messenger RNA (mRNA), plays a crucial role in carrying genetic information. It transcribes the genetic code from DNA in the nucleus and transports it to the ribosomes in the cytoplasm. There, the mRNA sequence is translated into proteins, fulfilling the instructions encoded in the DNA.
Free NTA Biology Question and Answers
What is the basic unit of life?