Earth & Life Science: Characteristics, Theories, Ecosystems, Reproduction, and Cell Structure

Life science

Collection of disciplines made up of theories and principles that tackle living organisms.

Responds to the environment

Responding to the changes around them to survive.

Growth

increase in size

development

- differentiation of cells for specialization.

reproduction

Creation of offspring.

metabolism

Total chemical reactions in an organism.

homeostasis

Body's state of equilibrium.

Spontaneous generation

Describes that life comes from lifeless or nonliving material through a mysterious process.

Panspermia

States that life on Earth was seeded from a celestial source.

Primordial soup

Life started in a primordial soup of organic molecules.

Homeostasis

preservation of internal conditions in an organism.

Biodiversity

Diversity of life.

Evolution

Change in the inherited traits of an organism over generations, which leads to creation of new species.

Ecosystem

Consists of both biotic and abiotic components.

Food chain

Represents how energy is transferred across a series of organisms in the form of food.

Heterotrophs

Consumers who depend on other sources for their food.

Autotrophs

Producers who prepare their own food.

Trophic levels

Organisms are classified based on their hierarchy in the food chain.

Food web

Made up of multiple food chains linked together.

Symbiosis

Interaction where each organism interacts with one another to survive in an ecosystem.

Commensalism

One organism benefits, the other one is unaffected.

Mutualism

Both organisms benefit.

Competition

Organisms compete for resources.

Predation

Predation feeds on prey.

Parasitism

Parasite relies on a host for survival.

Asexual reproduction

1 parent, offspring is a clone of their parent, mitotic cell division, large numbers are produced in a very short time.

Sexual reproduction

2 parents, genetic variation, gametes produced by meiotic—while the zygote is produced by mitotic division, the number produced is less.

Chromosomes

a package of DNA containing part or all of the genetic material of an organism

Fragmentation

1 organism is divided into minor fragments; develops into individual ones which are fully grown.

Binary Fission

Separation of the parent cell into new daughter cells.

Protozoa

Unicellular eukaryotes that have complex internal structures.

Budding

Developed from a small part of the parent's body (Outgrowth).

Parthenogenesis

Self-impregnation resulting in the production of a zygote from an unfertilized egg (Virgin birth).

Fertilization

Union of sperm and egg cell.

Internal Fertilization

Happens inside the body of the organism.

External Fertilization

Happens outside the body of the organism.

Oviparous

Lays eggs.

Viviparous

Gives birth to babies.

Ovoviviparous

Does both lays eggs and gives birth.

Hermaphroditism

Animals that have 2 reproductive systems but still need to mate to avoid abnormal offspring.

Genetics

Concerned with the DNA of organisms and how it manifested their genes.

Chromosome

Thread-like structures located inside the nucleus.

Gene

Distinct segment of DNA responsible for an inherited trait.

DNA (deoxyribonucleic acid)

Carrier of genetic information.

Genetic Engineering

Artificial manipulation of DNA to modify an organism.

DNA Isolation

Target DNA and plasmid are isolated from their sources.

Ligation

Recombinant plasmid and foreign DNA are combined by DNA ligase.

Transformation

Insertion of a recombinant plasmid cell back into a bacterial cell, usually E.coli.

Selection

Selection of transformed bacteria using special galactose sugar called X-gal.

Cloning

Exact genetic copies of living things.

Pollination

Transfer of pollen from the anther (male) to the stigma (female).

Xenogamy

Cross-pollination.

Autogamy

Transfer of pollen to the same flower.

Geitonogamy

Transfer of pollen to a different flower on the same plant.

Offspring Characteristics

Genetically different from parents (mixture of traits) and introduces genetic variation (diversity) to the population.

Apomictic

Produces seed without fertilization.

Vegetative Propagation

Involves plant parts that produce buds from specialized parts and grow into a new plant.

Regeneration

Development of the separated plant into a new plant.

Natural Vegetative Propagation

When plants grow from specialized leaves, roots, or stems without human intervention.

Artificial Vegetative Propagation

When plants' growth requires human intervention.

Cell

The basic unit of life.

Unicellular Organisms

Microscopic organisms that have life processes that happen only within their single cells.

Multicellular Organisms

Organisms composed of many cells that function together to maintain their life.

Robert Hooke

Made the compound microscope and examined thin slices of cork.

Antonie van Leeuwenhoek

Observed motile objects.

Cell Theory

States that all living organisms are composed of cells, which have specific independent functions but work together for an organism to properly function.

Organelle

Different structures inside a cell that each have jobs or functions to complete within the cell.

Cell Membrane

Helps keep fluid and other organelles inside the cell.

Cell Wall

Outer layer of the plant cell that keeps everything inside the cell protected.

Cytoplasm

Fluid that fills the cell.

Nucleus

Control center; controls growth and reproduction.

Nucleolus

Found inside the nucleus.

Chloroplast

Converts light energy of the Sun into sugars.

Mitochondria

Performs cellular respiration or process in which nutrients are broken down and turned into energy (powerhouse, ATP).

Golgi Apparatus

Turns combinations of molecules into new ones, then sends them out of the cell or stores them.

Smooth Endoplasmic Reticulum

Attached to the nucleus; important in the creation and storage of lipids.

Rough Endoplasmic Reticulum

Works with ribosomes attached to it to help with the synthesis and packing of proteins.

Vacuole

Storage bubble that stores food and nutrients.

Ribosomes

Builds long chains of amino acids.

Peroxisome

Digests nutrients and helps break down toxic materials with the help of oxygen.

Lysosome

Digests nutrients and breaks down food with the help of enzymes.

Microtubules

Provide structure to the cell and help with cell division.

Centrioles

Helps the cell divide during meiosis and mitosis.

Difference Between Plant and Animal Cells

Plant cells have cell walls and larger vacuoles, while animal cells have no cell wall, only a cell membrane, and have centrioles.