Sex Determination, Genetic Disorders, and DNA Processes
Sex Determination
The mechanism of sex determination has always been a puzzle for geneticists. The initial clue about the genetic or chromosomal mechanism of sex determination can be traced back to some experiments carried out in insects. In fact, the cytological observations made in a number of insects led to the development of the concept of a genetic or chromosomal basis of sex determination.
Mutation
Mutation is a phenomenon that results in the alteration of DNA sequences and, consequently, results
Read MoreBiochemistry Essentials: Key Concepts and Q&A
Biochemistry: Key Concepts and Q&A
Metabolic Pathways and Cellular Respiration
- Which of the following metabolic pathways does *not* happen inside the mitochondria? Acetyl-CoA production
- Which of the following elements increase the activity of the pyruvate dehydrogenase complex (PDH)? All of them
- The flow rate through the Krebs cycle is controlled by: All of them
- Indicate the true statement about the respiratory chain and oxidative phosphorylation: In eukaryotes, oxidative phosphorylation occurs in
Understanding Ecosystems: Biotope, Biocenosis, and Biosphere
Omnivores include wild boars, chimpanzees, pigs, and humans. Every living thing depends on others for sustenance. Herbivores depend on plants, and carnivores depend on herbivores. To express the power relations in a group of living beings, we use diagrams called food chains.
Ecosystem Studies
Ecosystem studies involve:
- The interaction between organisms (who eats whom)
- Types of feeding (what they eat, how they reproduce)
- Their relationship with the environment (what happens when it’s hot, when there’s
Central and Peripheral Nervous System: Functions and Health
Central Nervous System
The central nervous system is formed by the spinal cord and brain. It is protected by the skull, spine, and meninges. Between the meninges is the cerebrospinal fluid. It has two zones:
- The gray matter is formed by cell bodies and dendrites.
- The white matter is formed by axons covered by myelin.
Spinal Cord
The spinal cord is a nerve cord that runs inside the spine. The gray matter is in the center, and the white matter is outside. Within the gray matter, there is a tube called
Read MoreEndoplasmic Reticulum and Centrosome: Structure, Function, and Roles
Endoplasmic Reticulum (ER)
The endoplasmic reticulum (ER) is an intracellular membranous system located between the plasma membrane and the nuclear envelope. Its membrane is continuous with the nuclear membranes. This divides the cytosol into two compartments: the luminal space (inside the ER) and the cytosolic space (outside the ER).
Rough Endoplasmic Reticulum (RER)
The RER has ribosomes attached to the cytosolic side of its flattened membranes. It consists of interconnected sacs or cisternae and
Read MoreHow Digestive, Respiratory, and Circulatory Systems Work
Digestive System
Overview
The digestive system processes food, converting it into simpler substances that the body can absorb. These nutrients then pass into the bloodstream to nourish the body’s cells.
Digestive Tract
The digestive tract is a 10-meter long duct consisting of the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.
Digestive Glands
Digestive glands secrete substances necessary for breaking down food. These glands include the salivary glands, liver, and pancreas.
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