Vocabulary Word Definition
CHAPTER 3
Somatic cells cell that reproduces by cell division; also called body cell
Gametes a haploid sex cell; a male gamete is called a sperm or sperm cell, a female gamete is called an egg or egg cell
Sperm (plural is sperm ) a male gamete
Egg (ovum) Eggs (ova) a female gamete; a structure produced by some terrestrial animals to protect the developing embryo
Meiosis the process that produces gametes, which have half the chromosome number as the parent
Haploid describes a cell with half the chromosome number of the parent; symbolized by n
Diploid describes a cell that has a complete set of chromosomes; symbolized by 2 n
Homologous chromosomes a pair of corresponding chromosomes
Meiosis I the first phase of meiosis
Meiosis II the second phase of meiosis; produces haploid gametes
Fertilization the joining or fusing of male and female gametes
Diversity the variety within and among different species
Allele different form of the same gene
Dominant allele an allele that will express its trait (the trait will show up in a person’s appearance) if it is present in the cell
Recessive allele an allele that will express its trait (the trait will show up in a person’s appearance) only if both of the homologous chromosomes contain the recessive allele
Conjugation a type of sexual reproduction in which two unicellular organisms transfer or exchange some of their genetic material
Hermaphrodite an organism that produces both male and female sex cells

Stamen the male reproductive structure in a flower
Filament a stalk that supports the anther on the stamen of a flower
Anther the part of the stamen that produces pollen
Pollen tiny grains produced by the anther; contain the male gametes
Pistil he female reproductive structure of a flower
Stigma the sticky part of the pistil that receives the pollen grain
Style a tube-like structure in a flower that connects the stigma to the ovary; pollen travels down the style to the ovary
Ovary a structure in the flower that contains the eggs; in animals the organ in which egg cells mature and are released
Petal coloured leaf-like structure found on most flowers; attracts organisms such as pollinators
Sepal tiny leaf-like structure that protects the flower while it is in the bud; found at the base of the flower
Pollination the process by which pollen is moved from the male structures of a flower to the female structures of the same or another flower
External fertilization the union of the egg and sperm outside the body
Internal fertilization the union of the sperm and egg inside the female
Embryo a developing organism produced from a zygote
Seed the fertilized egg in the ovary of a flower
Cotyledon seed leaf found inside a seed
Germinate start to grow
Radicle the part of the plant embryo that develops into the roots
Epicotyl the part of the plant embryo that becomes the stem and leaves
Hypocotyl the part of the plant embryo that pushes up through the soil and protects the epicotyl

Placenta An organ that develops around the fetus, and connects to the mother
Fetus Developing offspring
Umbilical cord
Attached the fetus to the placenta, carries waste out of and nutrients in to the fetus
Selective breeding two plants or two animals of one species that have desirable traits are bred with each other to produce offspring with the same traits as the parents
Artificial insemination a procedure that involves introducing sperm into the reproductive tract of the female by a method other than sexual intercourse
In vitro fertilization Fertilization of eggs with sperm in a perti dish (in a lab)
Recombinant DNA technology combining genes from different individuals or different species into a single molecule of DNA
Genetically modified organisms
(GMOs) an organism that contains genes that have been intentionally altered; includes many food crops