Bacteriophage Biology: Structure, Life Cycles, and Replication

Phage Structure and Components

Most bacteriophages (phages) possess a distinct structure. Tailed phages, comprising about 95% of known phages, have double-stranded DNA (dsDNA) enclosed within a protein capsid shell. The majority feature a tail, which can be:

  • Long and flexible
  • Long and contractile
  • Short

An adsorption apparatus, including tail fibers and tail spikes, facilitates attachment to host cells.


Measuring Phage Infections: The One-Step Growth Curve

Viral infections, including those by phages, can

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Understanding Assisted and Artificial Reproduction Techniques

Assisted and Artificial Reproduction Techniques

Assisted reproduction, also known as artificial reproduction, involves the insertion of sperm into a woman’s uterus, timed to coincide with ovulation.

In Vitro Fertilization (IVF)

In in vitro fertilization (IVF), eggs are removed from the woman after hormone treatment to stimulate the ovaries. The eggs are then fertilized by sperm. When the sperm count is low, a single sperm can be injected directly into the oocyte using intracytoplasmic sperm injection

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Photosynthesis: Light Energy to Chemical Transformation

Photosynthesis: Transforming Light into Chemical Energy

Photosynthesis, occurring within chloroplasts, is the transformation of light energy into chemical energy. This energy is used to produce organic matter from inorganic substances. It’s essentially the reverse of respiration and is a constructive process.

Solar energy is absorbed by photosynthetic pigments in chloroplasts and used for the synthesis of ATP and glucose from CO2 and H2O. In mitochondria, the released energy is stored in the form

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Somatic vs Germ Cells: Understanding Cell Division

Somatic Cells and Germ Cells

Somatic cells: These cells make up the body tissues of a living organism. They divide by mitosis and always have two sets of chromosomes or genetic material (2n), making them diploid.

Germ cells: These cells merge with another cell to form a new sexual being. They divide by meiosis and only have one set of chromosomes (n), making them haploid cells.

Haploid and Diploid Cells

Number of chromosomes:

  • Haploid: Contains half the normal number of chromosomes (23).
  • Diploid: Contains
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Blood Composition, Functions, and Vessels: A Detailed Look

Blood: Composition and Functions

Blood is a viscous, salty-tasting liquid that circulates within the circulatory system. The average human body contains approximately 5.5 liters of blood.

Key Features of Blood

  • Carries nutrients and oxygen to all cells.
  • Collects waste products from cell metabolism.
  • Plays a crucial role in defending the body against infection.
  • Transports hormones, which are essential for controlling bodily functions.
  • Participates in regulating body temperature by distributing heat from warmer
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Plant Biology: Nutrition, Transport, and Gas Exchange

Plant Biology

Nutrition, Transport, and Gas Exchange

1. Introduction

Plants perform essential processes such as nutrient uptake, food digestion, gas exchange, transport, metabolism, and excretion. This document will explore these processes in detail.

2. Plant Structure and Function

Plants, such as algae and cormophytes, have specialized structures for different functions. Cormophytes possess leaves for photosynthesis, stems for support and circulation (xylem and phloem), and roots for water and nutrient

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