Science Semester 1 Final Flashcards
Exponential Growth
Populations grows without limit. Ex: human population.
Logistic Growth
Population grows quickly at first and then levels off. Ex: most natural populations (fish, rabbits, trees, etc.)
Carrying Capacity
The theoretical maximum population that a given environment could support.
Limiting Factor
Aspects of the environment that limit the size a population can reach
Density-Dependent Limiting Factors: Definition and Examples
Limiting factors that can be triggered by an increase in population size and thus crowding. They operate more strongly on large, dense populations than on smaller ones. Ex: Competition, Predation, Parasitism, Disease
Density-Independent Limiting Factors: Definition and Examples
Limiting factors that regulate population growth regardless of its size or density. Nearly all species in an ecosystem are affected equally by density-independent limiting factors. Ex: Weather Changes, Pollution, Natural Disasters
Habitat
The actual area in the ecosystem where an organism lives, including all of its abiotic and biotic resources. Many organisms share a habitat.
Niche
All the things an organism needs and does within its habitat - It’s “job” in the ecosystem. Each organism has its own niche.
Interspecific Competition
Where competition is occurring between different species
Intraspecific Competition
Where competition is occurring within the same species
Competitive Exclusion Principle
No two organisms can occupy the same niche at the same time. If the organisms are very different, one is probably a better fit than the other. If the organisms are similar, it will take a fight to see who will win. The loser will have to find a different niche to occupy.
Mutualism
Both organisms involved benefit. Helps both organisms survive.
Commensalism
One organism is benefited while the other is unaffected (neither benefited nor harmed).
Parasitism
One organism (parasite) benefits from the relationship, while the other organism (their host is harmed). However, it is crucial the parasite doesn’t kill the host, so that the parasite can survive and spread.
Competition
A relationship that exists between two or more organisms that are fighting for the same resource
Interspecific Competition
Where competition is occurring between different species
Intraspecific Competition
Where competition is occurring within the same species
What are the three principles of cell theory?
All living things are composed of one or more cells. Cells are the basic units of structure and function in an organism. Cells only come from existing cells.
Robert Hook
Scientist who observed cells in cork. Coined the term “cells”.
Anton van Leeuwenhoek
Scientist who created a powerful microscope and discovered bacteria
Robert Brown (2)
Scientist who noticed that pollen grains in water moved around - motion is called “Brownian motion”. Discovered the nucleus
Matthias Schleiden
A botanist who concluded that all plants are made of cells.
Theodor Schwann
A zoologist who concluded that all animals are made of cells
Rudolph Virchow
A physician who concluded all cells come from pre-existing cells.
Differences Between Prokaryotic and Eukaryotic Cells (5)
Prokaryotic: No nucleus. No membrane-bound organelles. Division is binary fission. Small and unicellular. Have cell walls made of peptidoglycan.
Eukaryotic: Yes nucleus. Yes membrane-bound organelles. Division is mitosis. Larger unicellular or multicellular. Only fungi and plants have cell walls (made of chitin or cellulose).
Similarities Between Prokaryotic and Eukaryotic Cells (5)
Cell membrane. Cytoplasm. Cytoskeleton. Ribosomes. Genetic Information (DNA or RNA).
Cell Membrane (Plasma)
Animal, Plant, Prokaryote. Controls what goes in and out of the cell.
Phospholipid Bilayer
Two layers of fats. The fats are phospholipids with hydrophilic heads and hydrophobic tails. Proteins embedded. Composed of many parts that move around freely.
Cytoskeleton
Animal, Plant, Prokaryote. Give the cell shape. Can move organelles around. Provide structural support for animal cells (who don’t have a cell wall).
Cytoplasm
Animal, Plant, Prokaryote. Holds everything in place. Provides a solution for chemical reactions to take place in.
Nucleus
Animal, Plant. Protect the DNA that controls the activity of the cell.
Nucleolus
Animal, Plant. Inside the nucleus. Make mRNA which make up ribosomes.
Mitochondria
Animal, Plant. Structure: Where cellular respiration happens. Breaks down food to release energy. Powerhouse of the cell.
Smooth Endoplasmic Reticulum
Animal, Plant. Job: Makes lipids (membranes). Destroys toxins (liver). Regulates calcium (muscles).
Rough Endoplasmic Reticulum
Animal, Plant. Structure: Ribosomes on the surface. Hugs the nucleus. Job: Makes, transports, and modifies proteins.
Ribosomes
Animal, Plant, Prokaryote. Make proteins!
Golgi Apparatus
Animal, Plant. Gets vesicles of protein from ER. Vesicles are like mini-carts that transport proteins around the cell. Processes, sorts, and ships protein where needed.
Vacuoles
Animal, Plant. Structure: Small and numerous in animal cells. One large central vacuole in plant cells. Job: Storage (water, nutrients, waste, etc.)
Lysosomes
Animal. Structure: Contain enzymes. Job: Breakdown dead stuff (food, bacteria, old parts of cells, etc.). Can do programmed cell death (apoptosis).
Cilia and Flagella
Animal/Prokaryote. Structure: Cilia - shorter, more numerous, like tiny oars. Flagella - longer, fewer. Job: Cilia - Move fluid across the cell surface. Flagella - move entire cell. NOT in all cells!