Chapter 4 Vocab Science

Nucleus

organelle that controls all the activities of a cell and contains heredity material made of proteins and DNA

Mitosis

cell process in which the nucleus divides to form two nuclei identical to each other, and identical to the original nucleus, in a series of steps (prophase, metaphase, anaphase, and telophase)

Chromosome

structure in a cell’s nucleus that contains heredity material

Asexual reproduction

A type of reproduction–fission, budding, and regeneration–in which a new organism is produced from one organism and has DNA identical to the parent organism

Organism

any living thing; uses energy, is made of cells, reproduces, grows, and develops

Sexual reproduction

a type of reproduction in which two sex cells, usually an egg and a sperm, join to form a zygote, which will develop into a new organism with a unique identity.

Sperm

haploid sex cell formed in the male reproductive organs

Eggs

haploid sex cell formed in the female reproductive system

Fertilization

in sexual reproduction, the joining of a sperm and an egg

Zygote

new diploid cell formed when a sperm fertilizes an egg; will divide by mitosis and divide into a new organism

Diploid

cell whose similar chromosomes occur in pairs

Haploid

Cell that has half the number of chromosomes as body cells

Meiosis

reproductive process that produces four haploid sex cells from one diploid cell and ensures offspring will have the same number of chromosomes as the parent organisms

DNA

deoxyribonucleic acid; the genetic material of all organisms; made up of two twisted strands of sugarphosphate molecules and nitrogen bases

Mutations

any permanent change in a gene or chromosome of a cell; may be beneficial, harmful, or have little effect on an organism