BIO Ch. 6, 7, and 8

100,000 (common)

In copying DNA there is only 1 error in _____ cell divisions

Meiosis

production of Gametes; reproduction

Mitosis

cell division; replacement of lost or damaged cells

Infertility

affects one in ten American couples

In Vitro Fertilization (IVF)

A sperm and an egg are joined in a petri dish

Asexual Reproduction

single-celled, eukaryotic organisms reproduce by simple cell division (ex. spirogyra); create identical organisms

Genome

complete set of an organism’s genes, located mainly on chromosomes in the cell’s nucleus

Chromosomes

condense during cell division, aided by Chromatin (proteins and enzymes)

Interphase: G1

Growth and development of the cell; 1 Chromosome/Genome

Interphase: S phase

genome/chromosome duplicated via DNA replication

Interphase: G2

Further growth and development, preparation for Mitosis

Interphase

90% of the cell’s cycle

10%

Mitosis is ___ of the cell cycle

Prophase

Centrosomes begin to separate, create spindle fibers; chromosomes begin to form; nuclear membrane breaks down, centrosomes take position at opposite regions, spindle fibers attach to chromosomes and move them around.

Metaphase

Chromosomes lined up in middle of the cell by spindle fibers (metaphase plate)

Anaphase

Spindle fibers retract, back towards polar regions; chromosome and its copy are separated. Spindle fibers not attached to chromosomes push away from each other

Telophase

one complete set of chromosomes in northern part, one complete set of chromosomes in southern part

Cytokinesis

Cell divided into two exact duplicates with identical genetic material; nuclear membrane begins to reform in each one, chromosomes condensed.

Daughter Cells (Mitosis)

two cells formed after cell division; diploid (contain all genetic info of that organism), identical

Cleavage furrow

Only in animal cell cytokinesis

Cell plate

formed in plant cell cytokinesis, creates a new cell wall and new membrane on either side of the cell; split into two.

Homologous Chromosomes

Chromosome 1 from each parent; 46 in human somatic cells

Autosomes

Chromosomes 1-22

Sex Chromosomes

Last 2 chromosomes; 23/24.

Chromatids

portions of a chromosome/arms of a chromosome

Sources of Genetic Variation

independent assortment, crossing over (which chromosomes touch/exchange info, not consistent), and random fertilization (which gametes will pair up during fertilization)

Independent Assortment

every chromosome pair orients independently of the others during meiosis (think like a combination lock)

Polyploids

Are new species (cannot breed with the parent’s species) that have more than 2 sets of homologous chromosomes in each somatic cell. (ex. certain rats)

The Cell Cycle

Consisting of the Mitotic phase (M) and Interphase (S-phase; includes cell growth and chromosome duplication)

Daughter cells (Meiosis)

4, haploid, have variation

“wild” type

most popular phenotype found in any population (most “commonly found in nature”)

Genetic testing (on humans)

Such as amniocentesis and CVS, allows expectant parents to test for possibilities in their unborn child; has risks.

Gregor Mendel

first person to analyze patterns of inheritance; deduced the fundamental principles of genetics

True-breeding

Offspring breed “true” (ex. if you cross a purple-flowered pea with a purple-flowered pea, all offspring will have purple flowers)

Monohybrid Crosses

A single character is chosen; two true breeding parents are crossed with different traits for that character (ex. tracking flower color).

4 Hypotheses Mendel developed

• alternative forms of genes = allele (ex. purple vs. white flower color)

• For each characteristic, each organism has 2 genes/alleles

• Gametes only carry 1 allele for each inherited characteristic

• Alleles = dominant or recessive

Heterozygote

2 different alleles (ex. Pp)

Homozygote

2 same alleles (ex. pp)

Mendel’s principle of segregation

Pairs of allele segregate (separate) during gamete formation; gametes fuse again at fertilization to create allele pairs.

Mendel’s Principle of Independent Assortment

Alleles are not inherited as a package, but separately, creating recombinants (mixes of both parent alleles)

Mendel’s main hypothesis in pea testing

Blending inheritance (2 parents genetic info is blended so that the children are a blend of both parents); once blended, cannot be unblended.

Dihybrid Cross

2 characters are chosen (ex. seed shape and seed color); 2 true breeding, homozygote parents that are diff. from each other; (16 squares)

Recombinants

Phenotype of Dihybrid Cross F2 generation

9:3:3:1

Family Pedigrees

Going backwards in generation to determine how genes are inherited