Chapter 4 science terms

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 has DNA identical to the parent organism.

Organism- Any living thing; uses energy, is made of cells, reproduces, responds, 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 unique identity.

Sperm-haploid sex cells 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 a sperm fertilizes an egg; will divide by mitosis and develop into an 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- Deoxyribonnuclei acid; the genetic material of all organisms; made up of two twisted strands of sugarphosphate molecules and nitrogen bases.

RNA

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

Gene

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

Mutation

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