Biol 1407 Unit 4: Animal Reproduction

Chapter 46: Animal Reproduction

• Sexual vs. Asexual Reproduction: Sexual reproduction involves the fusion of haploid gametes, while asexual reproduction does not involve gametes.
• Advantages and Disadvantages of Each Mode: Sexual reproduction promotes genetic diversity, while asexual reproduction is more energy-efficient and allows for rapid population growth. However, asexual reproduction limits genetic diversity.
• Examples of Animals: More primitive animals, such as sponges and hydra, tend to prefer asexual reproduction. Asexual reproduction is rare in most vertebrate animals.

Chapter 46: Animal Reproduction (continued)

• Internal vs. External Fertilization: External fertilization requires a moist habitat to allow sperm to swim to the egg. Internal fertilization enables sperm to reach an egg even in a dry environment, with fewer gametes produced, but a higher survival chance.
• Gonad: Organs that produce gametes (e.g., testes in males and ovaries in females).
• Male Reproductive Organs: Sperm are produced in seminiferous tubules in the testes, pass through the epididymis, and are propelled through the vas deferens and urethra.
• Female Reproductive Organs: Ovaries contain many follicles, each with a partially developed egg (oocyte). The egg cell travels from the ovary to the uterus via the oviduct (fallopian tube).

Chapter 46: Animal Reproduction (continued)

• Gametogenesis: The production of gametes from germ cells. Mutations in germ cells can pass down to offspring.
• Spermatogenesis: The formation of sperm, resulting in 4 sperm, with no interruptions.
• Oogenesis: The development of a mature egg, resulting in 1 egg, with a prolonged process that stops at menopause.
• Hormones Involved in Reproduction: The hypothalamus secretes GnRH, which directs the release of FSH and LH from the anterior pituitary. FSH and LH stimulate sex hormone production by the gonads.

Chapter 48: Neurons, Synapses, and Signaling

• Neurons: Nerve cells that transfer information within the body.
• Structure of a Neuron: Cell body, dendrites, axon, and synapses.
• Dendrites: Highly branched extensions that receive signals from other neurons.
• Axon: A longer extension that transmits signals to other cells at synapses.
• Synapse: A junction between an axon and another cell.
• Neurotransmitter: Chemical messengers that pass information from the transmitting neuron to the receiving cell.

Chapter 48: Neurons, Synapses, and Signaling (continued)

• Types of Neurons: Sensory neurons (transmit information about external stimuli), interneurons (integrate and interpret information), and motor neurons (transmit signals to muscle cells).
• Glial Cells: Supporting cells that nourish, support, and regulate neurons.
• Mechanisms of Signal Transmission: Resting potential, action potential, and the role of ion channels in depolarization.

Chapter 49: Nervous Systems

• Nerve: Axons of multiple neurons bundled together.
• CNS (Central Nervous System): Consists of the brain and spinal cord.
• PNS (Peripheral Nervous System): Consists of neurons carrying information in and out of the CNS.
• Glial Cells: Supporting cells of neurons with various functions.
• Structure of the Brain: Forebrain (cerebrum, thalamus, hypothalamus, amygdala), midbrain, and hindbrain (cerebellum, medulla, pons).

Chapter 49: Nervous Systems (continued)

• Cephalization: The clustering of sensory organs at the front end of the body, characteristic of bilaterally symmetrical animals.
• Neuronal Plasticity: The ability of the nervous system to be remodeled after birth.

Chapter 52: An Introduction to Ecology and the Biosphere

• Ecology: The scientific study of the interactions between organisms and their environment.
• Population Ecology: Analyzes factors affecting population size and changes over time.
• Community Ecology: Examines the effect of interspecific interactions on community structure and organization.
• Ecosystem Ecology: Emphasizes energy flow and chemical cycling between organisms and the environment.

Chapter 52: An Introduction to Ecology and the Biosphere (continued)

• Climate: Long-term prevailing weather conditions in an area, with four major components (temperature, precipitation, sunlight, wind).
• Biomes: Major life zones characterized by vegetation type or physical environment.
• Terrestrial Biomes: Tropical rain forests, deserts, savannas, chaparral, temperate grasslands, coniferous forests, temperate forests, and tundra.

Chapter 52: An Introduction to Ecology and the Biosphere (continued)

• Oceans: Salt concentration of 3%, covering 75% of the Earth's surface, with major impacts on the biosphere.
• Marine Biomes: Estuaries, intertidal zones, ocean pelagic zones, coral reefs, and marine benthic zones.
• Freshwater Biomes: Salt concentration of less than 0.1%, with lakes, wetlands, streams, and rivers.

Chapter 53: Population Ecology

• Population: A group of individuals of the same species living in an area.
• Population Density: The number of individuals per unit area, examined by counting, sampling, and mark-recapture methods.
• Population Dispersion: The pattern of spacing among individuals, including clumped, uniform, and random distributions.

Chapter 53: Population Ecology (continued)

• Survivorship Curves: Plots of the proportion of numbers in a cohort still alive at each age, with three types (Type I, II, and III).
• Exponential vs. Logistic Growth: The difference between unlimited and limited population growth.
• Carrying Capacity: The maximum population size that a particular environment can sustain.
• Factors Limiting Population Size: Density-dependent and density-independent factors.

Chapter 54: Community Ecology

• Interspecific Interactions: Any interaction between individuals of different species.
• Competition: Occurs when individuals of different species use a resource that limits survival and reproduction.
• Resource Partitioning: The differentiation of niches that enables similar species to coexist.
• Exploitation: Interaction in which individuals of one species benefit by feeding on individuals of another species.

Chapter 54: Community Ecology (continued)

• Mutualism: Interaction in which individuals of both species benefit.
• Commensalism: Interaction in which one species benefits, while the other is neither harmed nor helped.
• Defense Mechanisms: Aposematic coloration, cryptic coloration, Batesian mimicry, and Mullerian mimicry.

Chapter 55: Ecosystems and Restoration Ecology

• Ecosystem: All living organisms in an area and the abiotic factors with which they interact.
• Ecosystem Dynamics: Energy flow and chemical cycling.
• Trophic Levels: Primary producers, primary consumers, secondary consumers, tertiary consumers, and decomposers.

Chapter 55: Ecosystems and Restoration Ecology (continued)

• Trophic Efficiency: The percentage of production transferred from one trophic level to the next.
• Carbon Cycle: The movement of carbon through the ecosystem, including photosynthesis, respiration, and decomposition.

Chapter 56: Conservation Biology and Global Change

• Biodiversity: Includes genetic diversity, species diversity, and ecosystem diversity.
• Threats to Biodiversity: Habitat loss, introduced species, overharvesting, and global change.
• Biodiversity Hotspots: Small areas with numerous endemic and many endangered species.

Chapter 56: Conservation Biology and Global Change (continued)

• Eutrophication: The process of nutrient enrichment, leading to algal blooms and "dead zones".
• Biological Magnification: The concentration of toxins in organisms at higher trophic levels.
• Plastics: The most common type of marine waste, including microplastics.
• Climate Change: The increase in atmospheric CO2, driven by human activities, and its impact on ecosystems and biodiversity.

Chapter 56: Conservation Biology and Global Change (continued)

• Mass Extinctions: The cause of previous mass extinctions, including the rise of sea levels, continental drift, intense volcanic activity, and climate change.
• The 6th Mass Extinction: The potential current mass extinction due to human activities, which can pave the way for adaptive radiation.