Gen Bio 13-15 Study Guide

Gametes

Sex cells

Somatic Cells

Cells other than reproductive cells

Locus

term used to tell where a specific chromosome is on a gene

Karyotype

An individual’s complete set of chromosomes

Autosomes

any chromosome that is not a sex chromosome

Haploid Cell

a cell that contains a single set of chromosomes ex. egg/sperm

Zygote

diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum

Mutations

an alteration in the nucleic acid sequence of the genome of an organism

Asexual Reproduction

A single individual passes all of its genetics to its offspring without the fusion of gamets

Sexual Reproduction

two parents give rise to offspring that have a unique combo of genetic material from both parents

Meiosis I

Prophase I

Metaphase I

Anaphase I

Telophase I

Prophase I

each chromosome pairs with its homolog and crossing occur, X-shaped regions called chiasmata are sites of crossovers

Metaphase I

homologous chromosomes align along the equatorial plane of the cell, and chromosmes can cross over. the homologous chromosomes separate and move towards opposite poles of the cell.

Anaphase I

homologous chromosomes separate and move towards opposite poles of the cell, resulting in the separation of the pairs of chromosomes, but the sister chromatids remain attached.

Telophase I

Telophase I is a stage in meiosis where the chromosomes reach the opposite poles of the cell. The nuclear envelope reforms around each set of chromosomes, and the cytoplasm begins to divide

Meiosis II

prophase II, metaphase II, anaphase II, and telophase II. During _______, the sister chromatids separate, resulting in the formation of four haploid daughter cells.

Prophase II

nuclear envelope breaks down, chromosomes condense, and the spindle apparatus forms. This stage is characterized by the alignment of chromosomes along the equatorial plane of the cell.

Metaphase II

During ________, the sister chromatids of each chromosome separate and move towards opposite poles of the cell.

Anaphase II

the sister chromatids separate and move towards opposite poles of the cell

Telophase II

the chromosomes reach opposite poles of the cell, and nuclear envelopes start to form around the separated chromosomes. The cytoplasm divides, resulting in the formation of four haploid daughter cells.

Independent assortment of chromosomes

In _________, each pair of chromosomes sorts maternal and paternal homologs into daughter cells independently of the other pairs

Crossing over

________ produces recombinant chromosomes which combine DNA inherited from each parent, contributes to genetic variation by combining DNA from two parents into a single chromosome

Random Fertilization

__________ adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg), The fusion of two gametes produces a zygote with any of about 70 trillion diploid combinations

Trait

Each variant for a character, such as purple or white color for flowers

Character

A heritable feature that varies among individuals (such as flower color)

Allele

An allele is a variant form of a gene that determines a specific trait or characteristic

Phenotype

refers to the observable characteristics or traits of an organism

Genotype

refers to the genetic makeup of an organism, specifically the combination of alleles for a particular trait.

Homozygous

An organism with two identical alleles for a character is called a homozygote

Heterozygous

An organism with two different alleles for a gene is a heterozygote

Barr Body

Deactivated X chromosome in females