Bio Test 3

Asexual reproduction

Most bacteria produce this way. Example: Binary Fission

Cell Theory

All cells come from preexisting cells

Growth

Duplication of contents

Cell Division

Parent to daughter cells

Interphase

Majority of the cell cycle. 3 stages: G1, S, G2

G1

Stage before DNA replication. Double organelles, Accumulates DNA materials, Decide to divide or not (G0 arrested)

S

DNA synthesis, Duplicated chromosome (two sister chromatids)

G2

Stage following DNA synthesis, Makes proteins for cell division

Mitosis

Two identical daughter nuclei

M Phase

Duplicated chromosomes are composed of sister chromatids joined at the centromere. Each sister chromatid has identical DNA. Daughter chromosomes.

Spindle

Pulls chromatids apart. Part of the cytoskeleton. Made of microtubules.

Centrosome

Primary microtubule organizing center

Prophase

Chromosomes visible; condensed pairs

Metaphase

line up along equatorial plate (middle)

Anaphase

pulled to opposite poles of cell (apart)

Telophase and Cytokinesis

two distinct cells are visible

Plants

have centrosomes but lack centrioles

Animals

each centrosome has two centrioles and an aster

Cell plate

becomes new cell wall

Cleavage furrow

In animals, cell membranes form

Multinucleated Cell

Mitosis without cytokinesis

True

Cytokinesis accompanies mitosis in most cells

Muscle Cells

in vertebrate animals

Embryo Sac

in flowering plants

Rigid Cell Wall

Prevents furrowing.

Golgi Apparatus

produces vesicles

Signal

a molecule that stimulates or inhibits

Estrogen

Stimulates uterus to prepare for egg

Epidermal growth factor (EGF)

stimulates skin to repair injury. Contact inhibition

Cyclins

Present during certain stages of cell cycle

Kinases

remove phosphates from ATP, add it to other molecules

70 times

How many times does a cell divide

Senescence

Aging of cells. Due to shortening of telomeres

Apoptosis

Programmed Cell Death

Proto-oncogenes

Promote cell cycle & inhibit apoptosis. Mutations make oncogenes

Tumor suppressor genes

inhibit cell cycle & promote apoptosis

BRCA1 and BRCA2

breast cancer mutations

RB gene

retinoblastoma (tumor in the eye)

RET gene

thyroid cancer

Carcinogenesis

May be immortal, can block telomere degradation

Cancer Cells

Form Tumors, Angiogenesis

Benign

contained

Malignant

invasive

Metastatic

traveling

Cancer Treatment Options

Remove Tumor.

Interfere by radiation therapy and chemotherapy.

Hormone therapy.

Protective Behaviors

Avoid Smoking (30% of cancer deaths).

Avoid Sun Exposure (melanomas).

Avoid Alcohol

Protective Diet

Weight Loss.

Foods with Vitamin A and C.

Avoid salt cured or pickled foods.

Cabbage Family members

Meiosis

Reducing chromosome number. Shuffling chromosomes

Gametes

haploid sex cells

Homologous chromosomes

Also called homologues, have the same size, shape, and construction. Contain the same genes for the same traits.

Homologous pairs

contain different version of the same gene

Alleles

Alternate forms of the Gene

23 pairs

How many pare of chromosomes in a man or women?

22 pairs

autosomes

1 Pair

Sex chromosomes

Meiosis 1

Homologous pairs line up during synapsis resulting in tetrad. Homologous chromosomes of each pair then seperate.

Meiosis 2

No duplication of chromosomes.

Chromosomes are dyads (composed of two chromatins).

Chromatids are separated.

Two daughter nuclei separated.

Meiosis

sexually reproducing organisms and only inn specialized tissues

Mitosis

Is much more common. Occurs in all tissues during embryonic growth. Also occurs during growth and repair.

Nondijunction

Meiosis 1: both members of a pair go into the same daughter cell.

Meiosis 2: chromatids fail to seperate.

Trisomy

Three copies of a chromosome. Down Syndrome

Monosomy

single copy of a chomosopme

Trisomy 21

Recognizable characteristics. Short stature, eye lid fold, stubby fingers, mental disabilities.

Barr Body

Extra X chromosomes become

Y Chromsomes

Determines maleness

Turner Syndrome

Absence of second sex chromosome.

Female

Klinefelter Syndrome

Extra X inactivated as Barr body. Male

Jacobs syndrome in males

Results from nondisjunction during spermatogenesis. Fertile.

Garden Pea, Pisum Sativa

What did Mendel use in his experiment?

P Generation

Original Parents

3:1 Ratio

F1 parents contained two separate copies of each heritable factor. One dominant and one recessive

Law of Segregation

What was Mendels first law

Law of Segregation

Each individual has two factors for each trait. The factors segregate during gamete formation. Each gamete contains only one factor. Fertilization gives two factors.

One Trait Testcross

Determines whether an individual with a dominant trait has one or two dominant alleles

Chromosomal theory of inheritence

Chromosomes are carriers of genetic information. Explains only one gene for each trait is in a gamete in Meiosis

Alleles

Alternative form of a gene. Dominant masks recessive. Traits determined by inherited alleles. Alleles occur in gene locus

Genotype

alleles received at fertilization

Homozygous

Same

Homozygous dominant

GG

Homozygous recessive

gg

Heterozygous

Gg

Phenotype

physical expression of a gene

Law of independednt assortment

Each pair of factors segregates independently of other pairs. All possible combinations of factors can occur in the gametes.

Pedigree

chart of a family’s history regarding a particular genetic trait

Male

Square

Females

Circles

Shading

represents individuals expressing a disorder

Horizontal Line

between circle and square is a union

Vertical Line

down represents children of that union

Heterozygous

Carriers

Methemoglobinemia

skin appears blueish. Caused by lack of enzyme (Diaphorase) which converts methemoglobin to hemoglobin.

Cystic Fibrosis

characterized by abnormally thick mucus in bronchiole tubes and pancreatic ducts. Most common lethal genetic disorder in Caucasians in the U.S.

Alkaptonuria

build up of homogametic acid due to lack of enzyme homogentisate oxygenase.

Sickle Cell Disease

irregular shape of blood cell due to mutated hemoglobin. Results in anemia, internal hemorrhaging and episodic pain.

Osteogenesis

weakened, brittle bones. Mutated Collagen

Huntington’s Disease

progressive degeneration of neurons in the brain

Heterozygote

intermediate phenotype, phenotypes have blended but genotypes have not. The dominant allele does not completely mask the recessive allele

ABO

has 3 Alleles: IA IB i

IA and IB

Codominant

Polygenic traits

trait is governed by two or more sets of alleles