Cell Structure and Function
The Cell: Structure and Vital Functions
The cell is composed of three main elements: the membrane, cytoplasm, and genetic material. It performs three vital functions: nutrition, relationships, and reproduction.
The Plasma Membrane: Cell Boundary and Exchange
The plasma membrane acts as a boundary, limiting the cell’s contents while allowing the exchange of matter and energy with the surrounding environment. It consists of lipids, proteins, and carbohydrates. The plasma membrane has a fluid mosaic structure,
Read MoreRNA Synthesis: Transcription Process in Detail
The Synthesis of RNA (Transcription)
The synthesis of RNA, or transcription, occurs in the nucleus and requires:
- A DNA strand serving as a template: Of the two chains of nucleotides that make up the gene, only one, the template, is actually transcribed, while the other, called the coding strand, is not.
- Enzymes: The process is catalyzed by RNA polymerases. In prokaryotes, only one exists, whereas in eukaryotes there are three: RNA polymerase I, II, and III. RNA polymerase I is involved in the formation
Endocrine and Nervous Systems: Functions and Hormones
Endocrine and Nervous Systems
Nervous System: Fast action and very short duration. Effect is localized and fleeting.
Endocrine System: Action is slow but long-lasting. Effect is widespread, medium and long term.
Major Glands
Pituitary, Thyroid, Parathyroid, Adrenal, Pancreas, and Ovary/Testicle.
Hormones
A hormone is any chemical secreted in body fluids by a cell or a group of cells that has a control function. It is secreted and acts at a specific location.
Local Hormones
Produced in the system itself
Read MoreDigestive and Urinary Systems: Key Functions
Digestive System Functions and Processes
- Which of the following is not a function of the digestive system?
Filtration - The activities of the digestive system are regulated by:
All of the above - Sandwiched between the layer of the circular and longitudinal muscle in the muscularis externa is the:
Myenteric Plexus - Functions of the large intestine include:
All of the above - Digestion refers to the:
B and C only - Functions of the stomach include all the following, except for:
Absorption of triglycerides - Which
Understanding Sheep Farming: Herd Composition and Practices
Sheep Farming: Herd Composition and Management
Sheep Herd Structure
Ewes (Bellies of the Herd)
- Reproductive females.
- Age: 1.5 years (paddock mated) to 6.5 years (5th breeding).
- Replacement rate: 20% annually.
- Constitute 70-75% of total females in the herd.
Borregas (Breeding Females)
- Breeding females.
- Age: 4-5 months (weaning) to 1.5 years (early races, paddock mated).
- Constitute approximately 20% of total females in the herd.
Rams (Breeding Males)
- Breeding males.
- Age: 1.5 years to 5.5 years.
- Replacement rate:
Photosynthesis, Monera, Protista, Fungi, Plantae, and Animalia Kingdoms
Photosynthesis
In the photosystems, [light energy] is used to form NADPH. In the electron transport chain, the energy of those electrons is used to form ATP. The dark phase occurs independently of light, without using chlorophyll. It takes place in the stroma, and it uses the energy (ATP and NADPH) of the light-dependent phase to fix carbon dioxide and obtain organic molecules. The carbon source is CO2, the source of nitrogen is nitrates and nitrites, and the source of sulfur is sulfates. All this
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