Bio- Unit 4 Test

Autosomes

-Any chromosome that is not a sex chromosome Regulates all characteristics of the body -In humans there are a total of 46 chromosomes (there are 23 pairs)

Prophase II

-Centrioles move to opposite ends of the cells -Spindle fibers assemble

Cytokinesis

-Cytoplasm splits resulting in 4 haploid genetically different cells

Interphase

-DNA is replicated -Cell undergoes normal functions -Longest stage

Diploid

-Diploid cells contain two complete sets (2n) of chromosomes -They are pairs of homologous chromosomes (of maternal and paternal origin)

Haploid

-Haploid cells contain only one complete set of chromosomes/half the number of chromosomes as diploid -They are non-homologous chromosomes

Metaphase I

-Homologous chromosomes line up along the equator -Each side of the equator has chromosomes from both parents

Anaphase I

-Homologous chromosomes separate and move to opposite poles of the cell -Sister chromatids remain attached

Telophase II

-Nuclear envelope reforms -Spindle fibers break down

Prophase I

-Nuclear membrane breaks down -Centrioles move to the opposite ends of the cell -Chromatin condenses

Meiosis

-One cell divides twice to produce 4 daughter cells -These four daughter cells only have half the number of chromosomes of the parent cell-they are haploid -Produces sex cells or gametes (eggs in female, sperm in male) *Doesn't produce any other types of cells

Somatic cells

-Regular body cells; e.g. neurons, blood cells, liver cells, hair cells, etc. -Diploid (e.g., 46 chromosomes in humans) -Created through mitosis (turns on diploid cells into two diploid cells that are identical)

Gametes

-Sex cells that can be used to create offspring (sperm or egg cells are examples of gametes) -Haploid (e.g., 23 chromosomes in humans)-> each parent contributes 1/2 the total DNA to the offspring -Created through meiosis (turns one diploid cell into four, genetically diverse haploid gametes)

Metaphase II

-Single chromosomes align along the equator

Anaphase II

-Sister chromatids are pulled apart and moved to opposite ends of the cell

Meiosis

-Solely used for the production of gametes-sex cells, or sperm and eggs -Its goal is to make daughter cells with exactly half as many chromosomes as the starting cell had -In humans, meiosis is a process that takes us from a diploid cell to an entirely new haploid cell

Telophase I

-Spindle fibers dissemble -Cell will undergo cytokinesis to form two diploid genetically different cells

Crossing over

-The exchange of chromosome segments between homologous chromosomes -Occurs during Prophase I of meiosis I -Results in new combinations of genes

Sex Chromosomes

-The pair of chromosomes that determines the sex of an organism -They regulate the sex-linked traits

Meiosis Stages

n

Homologous Chromosomes

A pair of chromosomes that pair up with each other inside a cell during fertilization (one from each parent).

In Meiosis, crossing over during what stage increases genetic diversity?

Prophase