Cells and DNA

Cell

The basic unit of structure and function in living things

prokaryotic cell

cell that does not have a nucleus or other membrane-bound organelles.

Eukaryotic cells

have a nucleus and other membrane-bound organelles

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Nucleus

Control center of the cell

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

base pairs

A-T

G-C

double helix

two strands of nucleotides wound about each other; structure of DNA

Gene

A segment of DNA on a chromosome that codes for a specific trait

Trait

A characteristic that an organism can pass on to its offspring through its genes.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

sex chromosomes

One of the 23 pairs of chromosomes in the human, contains genes that will determine the sex of the individual.

autosomal cells

the other 44 chromosomes besides the sex chromosomes

sex cells (gametes)

(sperm and eggs) have half the number of chromosomes of a normal body cell

autosomal cells

body cells or any non-sex cell

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

Genetic Variation

Differences among individuals in the composition of their genes or other DNA segments

benefits of asexual reproduction

Allows for rapid reproduction. This means the parent organism will produces the greatest number of offspring for the same nutrients, space, and sunlight

No mates required

Very little / no investment of energy resources

Benefits of sexual reproduction

Sexual reproduction produces a greater chance of variation within a species than asexual reproduction would.

This variation improves the chances that a species will adapt to his environment and survive.