Chpt. 4 Vocab.

science

Nucleus

Organelle that controls all the activities of a cell and contains hereditary 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 hereditary 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, responds, grows, and developes.

Sexual Reproduction

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

Sperm

Haploid sex cell formed in the male reproductive organs.

Egg

Haploid sex cell formed in the female reproductive organs

Fertilization

In sexual reproduction, the joining of a sperm and egg.

Zygote

New diploid cell formed when the sperm fertilizes an egg; will divide by mitosis and develop 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 organism.

Heredity

The passing of traits from parents to offspring.

DNA

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

Gene

Section of DNA on a chromosome that contains instructions for making specific proteins.

RNA

Ribonucleic acid; a type of nucleic acid that carries codes for making proteins from the nucleus to the ribosomes.

Mutation

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