Human Reproduction and Development
Human Reproduction
Humans reproduce sexually. Women produce female gametes (ova), and men produce male gametes (sperm). Fertilization occurs when these gametes meet to form a zygote. These gametes are produced in the gonads: ovaries (female) and testicles (male). Fertilization is internal, meaning the egg and sperm unite within the female’s reproductive tract. Humans are viviparous, as the development of the new being occurs inside the mother.
Reproduction includes the following processes:
- Production
Understanding Genetics: Locus, Alleles, and Inheritance
Understanding Basic Genetic Concepts
1. Defining Locus and Allele
Locus: The specific, fixed position on a chromosome where a particular gene is located.
Allele: One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. Each allele controls a specific trait or characteristic.
2. Phenotype vs. Genotype: Observing Similarities
When observing similarities between a baby and their parents, we are looking at the phenotype. The phenotype is the
Read MoreInvertebrate Animals: Porifera, Cnidarians, Mollusks, Annelids, Arthropods
Invertebrate Animals: Porifera, Cnidarians, Mollusks, Annelids, and Arthropods
1. Porifera (Sponges)
Porifera, also known as sponges, are aquatic animals, generally marine, living fixed to rocks in shallow water. The body of a sponge has the form of a bag and is full of holes. Its walls are perforated by small pores, and part of it has a larger hole called an osculum.
2. Cnidarians
This group includes jellyfish, sea anemones, hydras, and corals. All these animals are aquatic and live in both fresh and
Read MoreHuman Reproduction: Organs and Functions
The Key to Life: Reproduction
Reproduction is a biological process that enables the creation of new organisms, a common feature of all known forms of life. This kind of reproduction occurs between two individuals of different sexes (male and female). Human reproduction uses internal fertilization, and its success depends on the coordinated action of hormones, the nervous system, and the reproductive system. The gonads are the sex organs that produce gametes (oocytes and sperm).
The Male Gamete: Spermatozoon
The
Read MoreUnderstanding the Human Respiratory System: Anatomy and Function
Understanding the Human Respiratory System
The respiratory system is a set of organs responsible for the entry and exit of air into our body. Air enters through the nostrils, which connect to the nasal passages. Air can also enter through the mouth, passing through the pharynx and into the esophagus. The first section of the esophagus is the larynx, formed by a series of cartilages. Next, air enters a rigid tube called the trachea, which eventually divides into two branches called bronchi. Each bronchus
Read MoreWorkplace Hazards: Identifying and Mitigating Risks
Workplace Hazards
1. Defining Occupational Hazards
An occupational hazard is the possibility of a worker suffering an injury due to conditions inherent in their job.
A hazard is considered serious and imminent when it is reasonably likely to occur in the immediate future and poses a significant threat to worker health.
2. Working Conditions and Safety
Safe working conditions encompass:
- General characteristics of premises and facilities.
- Work equipment: machinery, tools, products, and workplace tools.
- Environmental