Honors Biology Final Exam Review 1

Energy

Flows one way through an ecosystem

Matter

is recycled through organisms over time

Carbon

is fixed through photosynthesis and the action of plants

Nitrogen

in the atmosphere must be trapped by bacteria before it enters the ecosystem

Ecosystem

All the organisms along with the environment is called a(n)

Producers

All energy in an ecosystem is originally trapped by _______, also called autotrophs. They provide all the energy for the other organisms in the ecosystem.

Decomposers

Organisms that complete the breakdown of dead organisms and allow the elements to return to the atmosphere or recycle through the ecosystem

Pioneer organisms

The first organisms to live in a totally new environment are called ________, and examples are moss and lichen.

Succession

The predictable change in plants and animals in an area over time

Secondary succession

If succession is disrupted by a natural disaster or man-made event, the communities begin another sequence called

Niche

The role or job of an organism in the environment is called ______ and can only hold one type of organism.

Biomes

Areas of unique communities on earth, like grassland or rainforest, and are determines or characterized by specific temperatures and precipitation

Community

The organisms in an area are called

Species

Organisms that can interbreed and produce fertile young are called

Autotrophs

Organisms that make their own food through photosynthesis

Consumers

A general name for all organisms that eat other organisms for food

Herbivores

Animals that eat plants

Carnivores

Animals that hunt and eat other animals

Scavengers

Organisms that eat recently dead organisms

Decomposers

Include bacteria and fungi, and function to break down dead matter to recycle it into the environment

Mutualism

when two organisms of different species "work together," each benefiting from the relationship

Commensalism

a relationship in which one organism benefits but the other is neither helped nor harmed

Parasitism

a relationship between the two living species in which one organism is benefitted at the expense of the other

10% rule

Describes how only 10% of energy is passed through each trophic level in a food chain

Characteristic of living things

1. Made up of cells

2. Reproduce

3. Are based on a universal genetic code

4. Show growth and development

5. Obtain and use materials + energy

6. Respond to their environment

7. Maintain a stable internal environment

8. Evolve

Homeostasis

Maintaining a constant stable internal environment in a living thing

Carbohydrates

Made of simple sugars, provide energy and store energy for short-term, glucose

Proteins

Made of amino acids, control of reactions, fur

Lipids

Made of glycerol ad fatty acids, long-term energy storage, main component of membranes, fats

Nucleic acids

Nucleotides, hereditary info, directs cell activities, DNA and RNA

Phospholipids

A type of lipid that are a major component of cell membranes. They have a polar or hydrophilic head that faces to the outer area of the membrane, and nonpolar or hydrophobic tails that face to the inside area of the membrane

Enzymes

Specialized protein molecules that make a reaction happen faster. Each type only works on one kind of molecule called the substrate. It binds to this molecule at the active site

Denature

High heat, like a fever, or a change in pH can cause a protein (enzyme) to change its shape. This makes it unable to do its job.

Activation energy

Enzymes are catalysts. They speed up reactions by lowering…

Eukaryotic cells

Large, complex, nucleus, membrane-bound organelles, multicellular

Prokaryotic cells

Small and simple, no nucleus, no membrane-bound organelles, ribosomes (both), only found in single-celled organelles

Endosymbiont theory

Chloroplasts and mitochondria were originally prokaryotic cells that were taken in by another cell and set up a symbiotic relationship.

Evidence of the endosymbiont theory

1. Both mitochondria + chloroplasts must be made from pre-existing ones in a cell

2. Ribosomes + DNA = single circular DNA package

3. 2 membranes surround

Fluis mosaic model of a membrane

2 layers of phospholipids interspersed with proteins, and an integral protein

Semi-permeable

Only some substances can cross the membrane to enter or exit the cell

Diffusion

Name of the process of small molecules moving through a cell membrane. This movement is from an area of higher to lower concentration and does not require energy.

Osmosis

The movement of water through a cell membrane that does not require energy.

Active transport

Sometimes cells move molecules against the concentration gradient, fro low concentration to high concentration. This does require energy

Diffusion

Moves small molecules, moves from a higher to lower concentration, no energy required, travels through spaces

Osmosis

Moves water from a higher to lower concentration, does not require energy, travels through a protein channel

Facilitated Diffusion

Moves larger, polar molecules from a higher to lower concentration, does not require energy, moves through protein channels

Active transport

Moves any molecules from a lower to higher concentration, energy is required, moves through protein channels

Mitosis

Division of the nucleus, followed by the division of the cytoplasm. Results in 2 daughter cells with the same number of chromosomes as the original.

Interphase

Longest cell cycle phase, growth and copying of DNA occur in this stage.

Four stages of mitosis

Prophase, petaphase, anaphase, telophase (PMAT)

Cytokineses

Third stage of the cell cycle, division of the cytoplasm

Diploid

The normal number of chromosomes in a cell, 2N

Gametes

Sex cells have half the regular number of chromosomes or 1N (haploids)

Meiosis

The type of cell division that cuts the number of chromosomes in half to produce gametes. This process only occurs in ovaries and testes. it involves 2 sets of divisions. The number of chromosomes is cut in half in the Anaphase I stage. The result of this division is 4 1N cells.

Purpose of meiosis

Genetic variation and producing gametes

Crossing over

When homologous chromosomes trade segments of DNA during prophase 1

Independent assortment

When homologous chromosome line up and separate randomly in Anaphase 1

Fertilization

Union of the egg and sperm