A prokaryote is a simple, unicellular organism that lacks an organized nucleus or other membrane-bound organelle.Learning ObjectivesDescribe the structure of prokaryotic cellsKey PointsProkaryotes lack an organized nucleus and other membrane-bound organelles.Prokaryotic DNA is found in a central part of the cell called the nucleoid.
Green algae over the waters of a lake Introduction In the past, algae was classified as a primitive sub-kingdom in the plant kingdom. Most of it is currently classified within the Protist realm, or in another major group called eukaryotes, which includes more developed animals and plants.
Plant Cell: Various Types of Plant Functions What It Is The plant cell is very similar to the animal cell, it only differs from the second because it has a few more organelles, such as the cell wall and chloroplasts. Components and Functions The plant cell is made up of protoplasmic components (nucleus, endoplasmic reticulum, cytoplasm, ribosomes, golgi complex, mitochondria, lysosomes and plasts.
Tetrapods: the four-limbed terrestrial vertebrates What they are - meaning Tetrapods are terrestrial vertebrate animals, which have four limbs. These animals belong to the Tetrapoda superclass. Amphibians, mammals, reptiles and birds are tetrapods. Evolution According to evolutionary biology, the first tetrapods emerged about 350 million years ago from freshwater lung fish.
Scurvy: bleeding gums What is Scurvy Scurvy is a disease triggered by a lack of vitamin C (ascorbic acid) in the body. Symptoms of Scurvy Its symptoms are bleeding and gingival inflammation with consequent loss of teeth, inflammation and joint pain, hair loss, among others.
Zoologist: scientist who studies animals Professional - what he does The zoologist is the professional who is dedicated to the scientific study of animals. Besides being very fond of animals, this professional must have qualities and skills linked to the scientific research of animals. Because zoology is a very wide area, since there are so many species of animals, there are specialties about the zoologist's work.
Centrioles Observed by Electron Microscope What They Are - Definition Centrioles are structures present in the cytoplasm of eukaryotic cells of the vast majority of animal species (including those of humans). Main features: - Have cylindrical shape; - Centrioles consist of nine triple microtubules; - Centrioles are located in the center of the cells; - are arranged in pairs; - Have the ability to self-duplicate.
Fungi: simple life form What they are - biological definition In nature there are different types of fungi. We can say that they are a fairly simple life form. Regarding differences, there are those that are extremely harmful to human health, causing numerous illnesses and even intoxication.
Blood Cells - Microscope Image Introduction All living things are made up of cells. They can be unicellular (formed by only one cell) or multicellular (formed by several cells). Key Characteristics of the Animal Cell The cell is the smallest unit of the living being. In the human body there are different types of cells, and each type plays a specific role in maintaining life in the body.
Spinal cord: Located inside the vertebrae What is it? The inside of the vertebrae (some of them) contain a nerve mass, divided into two regions: gray and white. The spinal cord is called the set of neurons that make up these masses, which have distinct functions, which will be known below.
Neuron: the main element of human nervous tissue Introduction Nerve tissue is a set of cells in the human body that is responsible for performing specific tasks in our body. This complex structure is of fundamental importance for the proper functioning of our body, as it performs fundamental functions, mainly related to the coordination of bodily activities.
Reptiles: Many Species Across the World Most Known Examples of Reptiles: - Loggerhead Turtle - Green Tartature - Leatherback Turtle - Olive Turtle - Wetland Turtle - Mata-kills - Nile Crocodile - Jabuti -throat - Jabuti-tinga - Snake-necked Turtle - Pitiú - Tracajá - Jacaretinga - Crown Alligator - Paraguay Alligator - Green Alligator - Iguana - Lizard - Tropical Domestic Gecko - Teiú - Calango - Snakes - Constricting Boa - Parrot Snake - Spotted Sucur - Black Succulent - Yellow Sucur - Shoreline Snake - Guinea Fowl - Field Snake - Flat Snake - Jararaca- Water - Sucuri - Jararaca - Rattlesnake - Surucucu - Urutu - Wood Jararaca - Caiçara
Vertebral column: characteristic of vertebrates What they are - biological definition Vertebrate animals are living beings that have the most advanced organism on our planet. They have as main feature: spinal cord and spine (formed by vertebrae). Main general characteristics of vertebrate animals Other important characteristics are the fact that they have muscles and skeleton, which allows them to perform more complex movements.
Crocodile: example of crocodilian What they are - biological definition Crocodilians are large reptiles (order Crocodilia) found in various regions of the planet. Summary of the main general characteristics: - They have the body covered by scales; - have dermal bone plates covering the body; - They are oviparous animals, ie reproduction includes the laying of eggs in the external environment (where the animal develops before hatching); - They are semi-aquatic, living in places with freshwater (rivers, lakes, lagoons) and saltwater (mainly mangroves); - Crocodilians are carnivores.
Cytoplasm: Important Functions in Cells What is Cytoplasm - Definition In the cells of eukaryotes there is a space between the plasma membrane and the nuclear membrane. This space is called cytoplasm. Cytoplasm is composed of hyaloplasma, a colloidal (viscous) matter. In cytoplasm we find cell organelles (components of an animal cell).
Progesterone Molecular Structure What is progesterone Progesterone is a hormone produced by ovarian corpus luteum cells. The corpus luteum is a structure that develops in the ovary instead of a mature egg that has been released during ovulation. Consequently, the progesterone level rises during the second half of the menstrual cycle.
Jabuti: example of terrestrial turtles What they are - biological significance Belonging to the Chelonia order and also known as testudines, turtles are reptiles that have a carapace. There are currently cataloged about 300 species of turtles in the world. They inhabit mainly regions with large presence of rivers, lakes, seas and tropical forests.
Alligator: 60 day incubation period Introduction The incubation time of birds and reptiles varies from species to species. It lasts long enough for the animal to develop inside the egg until hatching (birth of the animal). Below is the average incubation time of some species. Species and incubation time (on average) BIRDS Agapomis - 23 days Albatross - 80 days Ostrich - 42 days Calafate - 15 days Swallow - 20 days Pheasant - 22 days Falcon - 29 days Chicken - 21 days Goose - 30 days Duck - 28 days Budgerigar - 18 days Peru - 26 days Penguin - 63 days Pigeon - 18 days Diamond Roller - 13 days REPTILES Alligator - 60 days Sea Turtle - 55 days Teiú - 60 to 90 days Caulking: only 15 days (one of the smallest among birds).
Aquatic beings: life in water What they are - biological definition Aquatic beings are all living beings living (all or part of their lives) in the waters of seas, oceans, rivers, lakes, among other means with water. Many aquatic beings live in salt water, especially in the oceans, while others are freshwater beings (rivers, lakes, streams, etc.).
Microscope: Extremely Important for Biological Discoveries Major advances and discoveries in biology: - 1665: British scientist Robert Hooke described for the first time in history a cell. To do this, Hooke used a microscope. - 1674: Dutch scientist Anton van Leeuwenhoek perfected a microscope of the time, allowing the observation of very small beings such as bacteria.