Biology 1.2 Review

Adaptations

(1) An evolutionary modification that improves an organism's chances of survival and reproductive success.

nucleus

A cell organelle in eukaryotes that contains the DNA and serves as the control center of the cell.

sexual reproduction

A type of reproduction in which two gametes (usually, but not necessarily, contributed by two different parents) fuse to form a zygote.

flagella

A unicellular nonphotosynthetic protist that has one or more long, whiplike flagella.

mutation

Any change in DNA; may include a change in the nucleotide base pairs of a gene, a rearrangement of genes within the chromosomes so that their interactions produce different effects, or a change in the chromosomes themselves.

is a term that encompasses all the changes that occur during the life of an organism.

Development

plasma membrane

Every cell is enveloped by a protective plasma membrane that separates it from the surrounding external environment.

_______describes the tendency of organisms to maintain an appropriate, balanced internal environment. The cellular mechanisms involved in this process are_______control systems.

Homeostasis, self-regulating

What would be the consequences to an organism if its homeostatic mechanisms failed? Explain your answer.

If an organism's homeostatic mechanisms failed, the organism could not maintain metabolic processes and it would die.

What characteristics distinguish a living organism from a rock?

Living organisms differ from a rock because they are characterized by cellular organization, growth and development, self-regulated metabolism, the ability to respond to stimuli, reproduction, and adaptation to environmental change.

We know that organisms come from previously existing organisms as a result of scientists like Francesco Redi in the 17th century and______ in the 19th century.

Louis Pasteur

organelles

One of the specialized structures within the cell, such as the mitochondria, Golgi complex, ribosomes, or contractile vacuole; many organelles are membrane-enclosed.

sessile

Permanently attached to one location (e.g., coral animals

asexual reproduction

Reproduction in which there is no fusion of gametes and in which the genetic makeup of parent and of offspring is usually identical.

homeostasis

The balanced internal environment of the body; the automatic tendency of an organism to maintain such a steady state.

cells

The basic structural and functional unit of life, which consists of living material enclosed by a membrane

cell theory

The scientific theory that the cell is the basic unit of life, of which all living things are composed, and that all cells are derived from pre-existing cells.

metabolism

The sum of all the chemical processes that occur within a cell or organism; the transformations by which energy and matter are made available for use by the organism.

Inherited characteristics that enhance an organism's ability to survive in a particular environment are called ______ . These inherited characteristics may be at the______ , physiological,______ ,_________ , or be a combination of all four.

adaptations, structural or biochemical or behavioral

Prokaryotic cells

are microscopic organisms classified in two large groups (called domains): domain Bacteria and domain Archaea.do not have a nucleus or other membrane-enclosed organelles.

In general, living things reproduce in one of two ways:_____ or_______.

asexually or sexually,

eukaryotic cells

cells typically contain a variety of organelles enclosed by membranes, including a nucleus,

Metabolism can be described as the sum of all the______ that take place in the organism.

chemical reactions

DNA

deoxyribonucleic acid, contain genetic instructions and transmit genetic information

Development

includes all the changes that take place during an organism's life.

Biological growth

involves an increase in the size of individual cells of an organism, in the number of cells, or in both.

Like animals, plants respond to______ , gravity,_____ , touch, and other_____.

light, water, stimuli

Organisms can be unicellular or

multicellular

The characteristics of life include: a precise kind of______ , growth and______ , self-regulated________ , the ability to respond to ______ ,_____ , and adaptation to_______.

organization, development, metabolism, stimuli, reproduction, environmental change

stimuli,

physical or chemical changes in their internal or external environment.oke a response in most organisms are changes in the color, intensity, or direction of light; changes in temperature, pressure, or sound; and changes in the chemical composition of the surrounding soil, air, or water

The two major cell types are and . These two cell types are distinguished by the presence or absence of a .

prokaryote, eukaryote, nucleus

Animals that do no move from place to place are said to be

sessile

Living things grow by increasing______ of cells,______ of cells, or both.

size, number

Physical or chemical changes in an internal or external environment that evoke a response from all life forms are called

stimuli

cilia

tiny, hairlike extensions of the cell