TTU BIOL 1402 Exam 2

Heredity

Inheritance of traits

Genes

parts of chromosomes; discreet unit of heredity information consisting of specific sequences in DNA or RNA

Locus

Site on a chromosome where the genes are found

Cross fertilization

(trick Mendel used being the "bee") animals and dioecious plants who only have individual sex gametes

Blending Theory of Inheritance

Theory that each parent's genetic material is mixed to create offspring

Particulate Theory of Inheritance

Traits are inherited like particles = genes

Monohybrid Cross

1 trait at a time cross

Allele Segregation

Mendel's 1st Law; Always produces 3:1 ratio

Allele

Version of gene: dominant vs. recessive; genotype

Pure-breeding strains

Crosses between identical homozygotes (same alleles)

Hybrid

An offspring resulting from the cross between two parents of different species Ss - just as long as SS (the little s is recessive and the dominant gene takes over

Test Cross

Long (?) + ss (allows you to determine genotypes)

Genotype

Alleles

Phenotype

Apparence

Punnett Square

shows a 9:3:3:1 ratio of phenotypes

Dihybrid Crosses

2 traits - 2 versions of that trait

Independent Assortment

Mendel's 2nd law; 9:3:3:1 rations of phenotypes in F2 generations

Sex Chromosomes

X and Y (1 Pair

Autosomes

The other 22 pairs

Criss- cross inheritance

how sex-linked (x chromosomes) genes are passes from mother to son

Incomplete Dominance

has to do with what enzymes do (make an enzyme or pigment directly); most genes make enzymes

Codominance

Heterozygote expresses both traits; "A" and "B" genes make structures (not enzymes) = sugar types

Epistasis

One gene supresses/ dominates a different gene rather than an allele

Polygenetic Traits

One trait is caused by many genes (whose effects are addictive)

Pielotropy (Syndrome - set of symptoms (traits))

One gene causes many traits

Expression (function of the environment)

May depend upon temp., nutrition, etc. Mutation causes change in enzyme

Mosaicism

Gene dosage of X in XX vs. XY

Double Helix

Shape of DNA: twisted ladder; bases point inwards, bases form rungs of a ladder; big (2-ring) base always pairs with a little (1-ring) base

Complementarity

Property of DNA or RNA, each has one nitrogenous base, and pairs up with another

Unwinding

Hydrogen bonds break and strands separate; enzyme unwinds the double helix breaking hydrogen bonds

Pairing

Free bases pair with their compliments

Joining

(DNA polymerase) - Enzymatic formation of backbone links

Histone

A small protein molecule associated with DNA and important in DNA packing in eukaryote chromosomes

Nucleosomes

Protect DNA

Sickle-Cell Anemia

spleen removes abnormal RBCs (dead); sickle has to do with the shape of red blood cells; causes by one mistake in the sequence of DNA

DNA vs. RNA

DNA: AGCT; Deoxyribose; Double Helix; Long chromosomes

RNA: AGCU; Ribose; Single Strands; Short chromosomes

Translation

Bilingual (mRNA and Protiens); redundancy; Triplet codon; Codon; tRNA (transfer RNA)

rRNA

type of ribonucleic acid that, together with protein, makes up ribosomes

Pedigree Analysis

Determines wether a gene is dominant or recessive and if it is sex-linked; study of family history

Karyotyping

To determine whether there is an abnormal # of chromosomes

RFLP's (restriction fragment length polymorphism)

DNA finger printing; cut DNA to various lengths

PCR (Polymerase chain reaction)

DNA amplification (increase amount)

Amniocentesis

Taking amniotic fluid to detect birth defects

Fetus

3 months through the birthing process

Chronic villi sampling

Detects brith defects in embryos

Embryo

fertilization (first 2 months of pregnancy)

Missense

Recessive mutation; BAD; Base substitution which converts one amino acid into another amino acid

Nonsense

Recessive mutation; BAD; coverts an amino acid into a stop codon, causing a shortened protein

Frameshift

Recessive Mutation; Base insertion or deletion, which shifts the reading frame

Nondisjunction

Phenomenon that causes abnormal number of chromosomes

Clitoris

Blub (grows into penis for a male)

Scrotum

Folds (labia in females) seals to form sac for the testicle

Urethra

Stays put in female; Grows out into the penis in males

Vagina

Genital opening in females = birth canal

Ducts

pipe tube

Vas Deferens

part of the male reproductive system that conveys sperm away from the testis;

Seminiferous Tublules

A coiled sperm producing tube in a testis

Interstitial cells

secrete testosterone between crevices

Testosterone

hormone made in testis (by interstitial cells) which causes male sexual traits

Epididymis

storage chamber- As sperm mature (grow tail, etc.) they travel into it

Seminal vesicle

Nutruent fluid = fuel; Keep sperm alive on their journey

Prostate gland

Alkaline fluid (base) = Hazmat kit; Neutralize acid (blocks yeast) in female reproductive track (of the vagina)

Bulbourethral gland

Mucus; for lubrication

Ovulation

a bursting of the follicle and a release of the follicle

Follicle

A cluster of cells that surrounf, protect and nourish a developing egg cell; secrete estrogen

Cervix

Narrow tube that baby's head must fit through; thick neck of the uterus which opens into the vagina

Uterus

in the reproductive system of a female, the organ where the development of young occurs (womb)

Oviduct

the tube that conveys the egg cells away from an ovary, also called the fallopian tube; site of fertilization

Endometrium

implantation of embryo into lining of the uterus

Bartholin's Gland

secretes mucus and functions as a lubricant in intercourse

FSH (Follicle stimulation hormone)

causes growth of the follicle and maturation; helps production of eggs by ovaries

LH (luteinizing hormone)

stimulates ovarian follicle causing an egg to grow

Ovary

female gonad which produces egg cells and reproductive hormones

Menstrual Cycle

28 days long, on day 14 (indicated by the internal clock) emits a pulse of LH and FSH

Menstruation

Day 0 when the lining of the uterus (endometrium) is released; release of blood and tissue from the uterus

Corpus Luteum

A gland; a small body of endocrine tissue and secretes progesterone and estrogen during and in extremely large quantities

Human Chorionic Gonadotrpin (HCG)

hormone produced in human placenta that maintains the CL during pregnancy (embryo)

Morphogenesis

Shaping of the intestines/ organs

Differentiation

Process of cellular specialization

Cleavage

Mitosis but no growth

Morula

Magical because it can adjust to size; split into twins or fused in chimeras

Blastula

About 10^3-10^4 cells roughly; embryonic stage that marks the end of cleavage in animal development, also a hollow ball of cells in many species

Blastocyst

Fluid filled spheres

Gastrulation

creation of the gastro intestinal tube = gut

Ectoderm

outermost layer of the gastrula and forms skin and central nervous system

Mesoderm

forms skeleton and muscles

Endoderm

forms gastrointestinal tract, stomach and other organs

Neurulation

Creation of the central nervous system (pipe;