NES 103 Science Flashcards
Homeostasis
All living organisms exhibit homeostasis, or the ability to maintain a state of internal balance. For example, if the environmental temperature increases, the human body begins to perspire, and the cooling effect of evaporation decreases the surface temperature of the skin. Likewise, a disruption in any system will set off a diverse set of control mechanisms that return the organism to a state of internal balance.
Energy
Every living thing needs energy that they produce or acquire in order to exist, grow, and reproduce. Some organisms (called autotrophic organisms) are capable of harnessing energy from sunlight and using it to produce glucose, the main source of energy for the organism. Others (called heterotrophic organisms) capture energy by eating plants or other animals.
autotrophic organisms
are capable of harnessing energy from sunlight and using it to produce glucose, the main source of energy for the organism.
heterotrophic organisms
capture energy by eating plants or other animals.
organelles
are specialized to fulfill specific functions within the cell. Mitochondria, for example, break down glucose to provide energy to the cell. Bacterial cells lack most of these organelles.
Mitochondria
break down glucose to provide energy to the cell.
Four basic types of tissues Humans have
connective, epithelial, muscle, and nerve.
epithelial
of or belonging to epithelium
epithelium
membranous tissue covering internal organs and other internal surfaces of the body
The human body has ___organ systems. Name them
11 systems Circulatory Digestive Endocrine Excretory Immune Integumentary Muscular Nervous Reproductive Respiratory Skeletal
Vascular plants have a stystem of tubes (____ _____ ______) that are used to transport nutrients and water
xylem and phloem
chlorophyll, which is contained within a cell organelle called the _____ captures the light from the sun
chloroplast
Chemical formula for photosynthesis
CO2 + 6 H2O → C6H12O6 + 6 O2
Carbon dioxide + Water + Light energy → Glucose + Oxygen
How many different kinds of life forms or species do scientist believe are on earth
10 million
What is the system currently used by taxonomists called and why?
It is called the Linnaean taxonomic system, in honor os Swedish biologists Carlous Linnaeus (1707-1778), one of the founders of the modern system of biological classification
Eukaryotes
consist of all organisms with cells that have true nuclei and membrane-bound organelles. Four kingdoms–animals, plants, protists, and fungi fit into this domian
Prokaryotes
Prokaryotes have neither nuclei nor organelles with membranes. True bacteria fit in this domain
Archaea
Archaea are microorganisms similar to bacteria in form but genetically so vastly different from everything else on the planet that they deserve their own unique branch on the tree of life. Archaea are often found in extreme environments including acidic conditions, boiling hots springs, deep ocean vents or polar ice.
Modern taxonomy uses genetic analysis and comparison of physical traits to classify organisms according to a hierarchy of taxonomic ranks. These include
Kingdom Phylum Class Order Family Genus Species
Egg
Eggs are laid by the adult female insect. Females lay a lot of eggs so that at least some o them will survive
Larva
Larva hatch from the eggs and bear no resemblance to their adult parents. They only have one job to eat so it can grow quickly. Can grow 100 times their size during this stage. Butterfly and moth larvae are caterpillars. Fly larvae are maggots and beetle larvae are grubs. Eventually, when growth is complete the larva is transformed into a pupa
pupa
the pupa stage is usually considered a resting stage, although much activitiy is going on within a sealed chrysalis or cocoon. Special cells that were present in the larva are now growing rapidly and will become the legs, wings, eyes and other parts of the adult insect. After the reorganization is complete, the pupa splits to reveal the mature adult with functional wings. This stage can last a few weeks, a month or even several years.
Incomplete Metamorphosis
About 12 percent of all insects go through incomplete metamorphosis. These include stinkbugs, earwigs, crickets, grasshoppers, cockroaches, ants, praying mantis, and dragonflies. Incomplete metamorphosis has only three life cycle stages: egg, nymph, and adult. The nymph looks similar to, but is a smaller version of, the adult. The nymph is also wingless. As nymphs grow, they shed their hard exoskeletons, a process called molting. There is no pupal stage during incomplete metamorphosis.
Incomplete metamorphosis has only three life cycle stages name them
egg, nymph, and adult
Heredity
Heredity is defined as the transmission of characteristics carried by the genetic code from one generation to the next. Characteristics may be physical, physiological, or psychological as long as they are carried by the genes. Heredity explains why offspring look like their parents and why dogs always give birth to puppies and never guppies or butterflies. Through heredity, living things inherit traits from their parents.
Genes
Chromosomes are microscopic, threadlike structures that contain the genes that carry hereditary information from one generation to the next. Each chromosome contains many genes. Different organisms may have different numbers of chromosomes. In sexually reproducing organisms, chromosomes occur in pairs—one chromosome of each pair comes from the mother and one from the father. Humans have 23 pairs of chromosomes. One pair, consisting of two X chromosomes (XX) in females or an X and a Y chromosome (XY) in males determines the gender of the offspring. The other 22 pairs are called somatic chromosomes because their genes produce proteins for building the body rather than determining gender. In eukaryote organisms, chromosomes, and their genes are found in the nucleus, which is surrounded by its own membrane. In bacteria, no nucleus is present and the chromosomes are found in the cytoplasm of the cell.
The other 22 pairs are called somatic chromosomes because…
their genes produce proteins for building the body rather than determining gender.
Simple food chain example
A simple food chain might look like this: sun → grass → grasshopper → toad → snake → hawk → bacteria of decay
Commensalism
In a commensal relationship, members of different species live together, and one member benefits without seriously affecting the other party. As a rule, the animal that benefits is usually the physically smaller of the two. The commensal organism may depend on its host for food, shelter, support, or transportation. The animal that benefits is known as the commensal, or symbiont, while the nonbenefitting species is known as the host. For example, some flatworms live attached to the gills of the horseshoe crab, obtaining bits of food from the horseshoe crab’s meals; the horseshoe crab is apparently unaffected.
Mutualism
In mutualism, members of two different species benefit by associating together. For example, many plant species require an animal to visit its flowers for pollination. The animal benefits in this relationship by having a source of food (nectar or pollen), while the plant benefits by having its ovules fertilized.