Human Reproduction: Cells, Cycles, and Processes
Human Reproduction
The Ability to Reproduce
A fundamental quality of all living things, including humans, is the ability to reproduce. Reproduction, unlike nutrition and interaction, is essential for the continuity of the species, perpetuating life through offspring.
Sexual Reproduction in Humans
Human reproduction is sexual, involving two parents of different sexes. Offspring inherit a mixture of characteristics from both parents. This process involves specialized reproductive cells called gametes:
Read MoreMatter, Energy, and Dynamics in Ecosystems
Matter and Energy in Ecosystems
In ecosystems, energy is transferred between organisms through trophic relationships.
Energy Flow
Energy flow is a unidirectional, open process. Ecosystems require a continuous energy supply for function. Energy enters ecosystems primarily from the sun. Producers use a small portion of solar energy reaching Earth to perform photosynthesis, converting light energy into chemical energy. Only the energy stored in organic matter transfers to the next trophic level.
Matter
Read MoreAnimal Behavior: Key Concepts and Exam Review
Exam 1
MC Answers
- TRUE: Certain complex animal behaviors may be controlled by a single gene.
- TRUE: One form of empirical study involves making field observations of animal behavior.
- TRUE: A conceptual approach to a problem involves taking older ideas and methods and combining them in new ways to make advances.
- TRUE: Cliff swallows nesting in large colonies, raised by foster parents in small colonies, later showed a preference for large colonies.
- FALSE: In large coalitions of male lions, members are usually
Organ Transplantation, Donation, and Regenerative Medicine
Organ Transplantation
Organ transplantation was a significant medical success of the 20th century. The first successful kidney transplant was in 1954. In 1967, Dr. Christiaan Barnard performed the first heart transplant. This therapy has dramatically improved the quality of life for many patients and offers a chance of survival for others.
Who Can Donate?
Receptors are individuals who need a transplant. Donors can be:
- Individuals declared brain dead: cessation of brain function, but organs remain viable
Plant Nutrition: Process, Phases, and Photosynthesis
Plant Nutrition
Nutrition is the process that plants use to manufacture their own organic matter and perform other vital functions. To carry out this process, they need solar energy and other essential elements; 15 are from the land and 1 from the atmosphere.
Phase 1: Absorption
The first phase of nutrition is the absorption of water and mineral salts into the xylem vessels. The water and dissolved minerals are absorbed by the root hairs, across the different tissues, down to the wood vessels. This
Read MoreSynthetic Theory of Evolution
1. What is a Species?
A group of living things that share an evolutionary history, have common anatomical and physiological characteristics, and can reproduce to produce fertile offspring.
2. Main Proponents of Evolutionary Theories
Fijistas Theories
Species are products of a creator and are therefore fixed and immutable; they do not evolve.
Major Proponents:
- Plato and Aristotle: Although disagreeing on certain aspects of the natural world, they agreed that species were created and fixed.
- Carl Von Linné: