Unit 2 AOS 2 SAc Flashcards
What is viviparity in sexual reproduction, and how does it differ from other methods?
Viviparity (live-bearing) involves retaining fertilized eggs in or on a parent’s body. This derived mode of reproduction is thought to have evolved in response to various stresses on free-living larvae, such as predation, limited food resources, drying, cold temperatures, etc.
What is oviparity in sexual reproduction, and which animals use this strategy?
Oviparity is the process of reproduction in which embryos develop inside eggs that are laid outside the mother’s body. Birds, most reptiles, and some fish reproduce this way.
Why is genetic diversity important for the survival of a species or population?
Genetic diversity allows populations to adapt to changing environments and resist diseases, increasing their chances of survival and reducing the risk of extinction.
What are the biological advantages of sexual reproduction?
Sexual reproduction increases genetic diversity, which enhances adaptability and resilience in offspring, enabling species to better survive environmental changes and potential diseases.
What are the advantages and disadvantages of asexual reproduction?
Asexual reproduction is advantageous because it is fast and requires less energy, allowing rapid population growth. However, it produces genetically identical offspring, reducing adaptability to environmental changes.
What is the purpose of reproductive cloning technology in plants?
Reproductive cloning in plants ensures consistency in traits like disease resistance, growth rates, and yield, making it useful in agriculture to produce high-quality crops.
What are some reproductive cloning technologies used in animals?
Techniques like somatic cell nuclear transfer (SCNT) and embryo splitting are used in animals to create genetic copies, often for research, conservation, or agriculture purposes.
What are the main ethical challenges associated with cloning?
Cloning raises ethical concerns, including animal welfare, premature aging of clones, potential human cloning, and reduced genetic diversity, along with the ethical treatment of research animals.
What is somatic cell nuclear transfer (SCNT), and how is it used in cloning?
SCNT involves transferring the nucleus from a somatic cell into an enucleated egg, creating an embryo that can develop into a clone of the donor organism. This technique is widely used in research and animal cloning.
How do animals adapt structurally, physiologically, and behaviorally to survive in hot environments?
Structural adaptations include insulation and high SA
ratio; physiological adaptations include evaporative cooling and concentrated urine; behavioral adaptations involve nocturnal activity and seeking shade to avoid extreme heat.
What are some structural adaptations in plants for surviving hot environments?
Plants may have smaller, light-colored, or vertically oriented leaves to reduce heat absorption. Some also develop extensive root systems to maximize water intake and minimize water loss through stomata.
How does torpor help animals survive in cold environments?
Torpor reduces metabolic rates and conserves energy, allowing animals to survive on limited resources during cold seasons. Examples include hibernation in mammals and brumation in reptiles.
What is countercurrent circulation, and why is it beneficial in cold environments?
Countercurrent circulation transfers heat between adjacent blood vessels, helping animals conserve core body heat by warming blood returning to the heart, which is essential in cold habitats
How does huddling behavior help animals conserve heat in cold environments?
By huddling, animals share body heat and minimize exposed surface area, which reduces heat loss and helps them stay warm, especially in species that live in groups.
What is an apex predator, and what role does it play in its ecosystem?
An apex predator is at the top of its food chain with no natural predators. It helps control the population of prey species, maintaining balance within its ecosystem.
What is a keystone species, and why is it essential to ecosystem health?
A keystone species has a disproportionately large impact on its environment. Its presence helps maintain biodiversity and ecological balance, as it influences the population and distribution of other species.