Asexual

Single-celled organism reproduces by replicating its genetic material and splitting the contents of one cell into two.

Sexual reproduction

the genetic makeup comes from two parents.

Somatic cells

do not participate directly in reproduction.

Germ cells

cells that gives rise to gametes in an animal

Gametes

a sex cell; sperm or egg

What happens to the chromosome number of a diploid germ cell in meiosis...

a diploid germ cell reduces its chromosome number by half to generate four haploid nuclei

Fertilization

merges gametes from two parents, creating a new cell

Zygote

is the first cell of the new organism

Alternation of generations

the life cycle of a sexually reproducing plant

Autosomes

a non sex chromosomes (does not determine if the individual is male or female) 

Sex chromosomes

carries genes that determine an individual‘s sex.

Homologous pair

chromosomes that look alike and carry the same sequence of genes for the same trait.

Homologous

 having the same basic structure.

Crossing over

is a process in which two homologous chromosomes exchange genetic material.

Alleles

an alternative form of a single gene

Polyploid

gamete with one or more complete set of extra chromosomes.

What does a Polyploid always refer to?

many sets

Nondisjunction

failure of chromosomes to separate at anaphase I or anaphase II of meiosis

Deletion

a loss of one or more genes from a chromosome.

Duplication

multiple copies of one or more genes.

Inversion

a portion of a chromosome that flips and reinserts itself.

Meiosis

occurs in the diploid plant, or sporophyte to produce haploid cells called spores

Oogenesis

formation of egg cells

Oogonium

in Oogenesis, diploid germ cells that divides mitotic ally to yield two primary oocytes

Polar body

small cell produced in female meiosis