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when an organism has two identical alleles for a given character ex. attached-attached-----homozygous for attached earlobes
A portion of DNA that codes for a given polypeptide chain- protein
Where does Spermatogenesis occur?
in the testes
Where are the ovaries found and what are the two purposes of oogenesis?
Found in the abdominal cavity and two purposes are: 1) produce egg cells, 2) secrete hormones estrogen and progesterone
Sometimes during meiosis the chroosomes do not seperate properly, gametes then end up with too many or few chromosomes
tubal ligation
cut and tie oviducts (fallopian tubes)
intrauterine device
plastic devices of various shapes that are placed in the uterus by physician;they don't know how they work, but somehow prevent implantation of zygote (probably scrape against the walls of uterus) no longer available in the US because of lawsuits against doctors
Mendel's law of segregation
when gametes are formed a diploid organism the alleles that control a given trait seperate from each other into different gametes and retain their individuality
spericidal foams and jellies
make fagina ore acidic, and kills sperm
Klinefelter's syndrome
results when a person has an extra sex chromosome 2x's and a y, 47 total chromosomes: egg had two x chromosomes, individual is tall sterile man, often with lower mental capacity
Where does Oogenesis occur?
In the ovaries which are suspended in the abdominal cavity.
surgical, usually permanant, some recent success in reversing
Variety is generated into a populations gene pool by and explain each?
1) mutations 2) sexual reproduction 3) Migration 4) Size of population, explanations in notes 4/5
clusters of genes
passes through the penis and empties to the outside
of thousands of seconday oocytes that are formed:
only 13 are ovulated each year, less than 400 ovulated in a lifetime, the rest disinigrate by age 50.
During puberty, the ovaries begin to release 1 secondary oocyte every 28 days.
What 3 glands is seminal fluid produced by?
1)seminal vesicles, 2)prostate, 3) cowper's gland
Many plants can be reproduced asexually to form a number of individuals with exactly the same genotype
As sperm passes through the vas deferens and urethra what is added to form semen?
sperm and seminal fluid
A coiled tube that lies on the surface of the testes and carries sperm to the vas deferens
Cause: bacteria, symptoms appear 3-14 days after sex, symptoms obvious only in male (discharge from penis and painful urination) treatment: penicillin but resistant strains more common
What are the two functional components of the testes and what is the purpose of each?
Seminiferous tubles (where sperm is produced), and Intersitial cells (secrete hormone, testosterone)
Over 20 million Americans have genital herpes, 1 in six sexually active people have genital herpes, cause by 2 viruses: Herpes simplex 1- cold sores and painful blisters on lips, Herpes simples virus 2- painful ulcers on genitals (genital herpes) symptoms: appears in 2-20 days. Virus stay in nerve cells while dormant type 1 can cause blindness, type 2 can cause meningitis more in notes
Who was the first person to systematically study patterns of inheritance and what did he do?
An austrian monk named Hohann Gregor Mendel, he conducted a series of experiences with ordinary garden peas. The laws he discovered where not accepted until 3 other researchers came up with the same conclusions.
Mendel's law of dominance
when an organism is heterozygous for a given trait, the allele that is expressed is said to be dominant: the allele that is over shadowed is said to be recessive
Alternative forms of genes for the same characteristic. ex. red, blonde, brunette
Chemicals(usually proteins or steroids) produced by one part of the body (usually a gland) that alters the activity of another part of the body called the target organ.
An organism that has different alleles for a given characteristic, attached-free
today many of our most important food crops are planted as a vast field of simular genotypes
During spermatogenesis the cells lining the seniferous tubules enlarge ad become what?
primary spermatocytes
Small vs. Large gene pools
Small gene pools can result in lowered adaptability to environental changes--may lead to extinction, a large gene pool with a great variety of genes is more likely to contain genes that will allow some of the organisms to survive (DDT and Flies)
membranous shield placed over erect penis before intercourse,
a group of organisms that have the ability to breed and produce fertile offspring. (have the same number and kinds of choromosomes and genes).
The characteristics of organisms are controlled by?
Recessive allele
the allele that is masked and does not express itself.
Population genetics
The study of why differences in gene frequencies (how often a gene occurs in a population)
notes 12/12
luteal phase
Populations gene pool
consists of all the genes of all the organisms in the population, as a result several factors such as geographic barriers or resource availability, the individuals within a population are usually found in clusters that breed with each other.
monohybrid cross
A gentic cross in which a single characteristic is followed from one generation to the next.
termination of zygote, embryo or fetus, 3 methods 1)dilation and curettage (D and C, which is also used to detect cancer), 2) suction devices, 3) injection of saline solution into uterus
Downs syndrome
(mongoloidism) occurs when there is an extra chromosome 21. 47 total chromosome in zygote, low level of intelligence, thickened eyelids, faulty speech
what is the genotype
The particular combination of alleles (genes) present in a given organism
the study of how genes control these characteristics and how they are passed on form generation to generation (inheritance)
When does Oogenesis begin?
Before the female is born
the way that this combination of genes expresses itself
flow phase
Vas Deferen
run into the abdominal cavity and joins the urethra just beyond the point where the urethra leaves the bladder.
Rythym method
refrian from sex on those days of the month when the secondary oocyte may be present
Pairs of alleles on nonhomologous chroosomes seperate independently of each other. follows mendel's law of independent assortment
The production of gametes
Where are the testes found
in the scrotum
Occurs when a gene has more than 1 effect on the phenotype of an organism, occurs often, sometimes one effect is good other bad.
The secondary Oocyte are incased in this saclike structure
polygenetic inheritance
some characteristics are deterined by several pairs of alleles on the same or different chromosomes
The production of sperm
What is polar body 1?
During cytokenesis one of the two cells formed during meiosis 1 gets less cytoplsm and eventually disinegrates.
some males release up to ________ per ejaculation?
1 billion sperm cells
Primary stage: in about 3 weeks a hard painful sore develops on genitals dissapears after a short time, no more symptos for 2-4 months, secondary stage: skin rash and infection of organs may enter latent period which last through life, may enter Tertiary Stage: severe nervous and circulatory system damage and even death. Treatment: penicilin, some resistant strains
Turner's syndrome
results when a person has only 1 x chromosome, 45 total chromosomes in zygote: one of the gametes is missing a sex chromosome. individual is female, sterile, short, webbed neck problems with math and spatial relationships
The small gene pool within a monoculture results in
1) the need for herbicides and pesticides to maintain the proper conditions for plant growth (cant breed hybrids resistant to everything) 2) a greater potential for a new disease to wipe out the entire population.
progesterone inhibits secretion of fsh and lh from the pituitary thus preventing follicular growth and ovulation
What did Mendel believe and how was he wrong?
He thought of a gene as a "particle" that was passed on from parent to offspring, but today we know genes are composed of specific sequences of DNA nucleotides
cut and tie vans deferens; sperm remain in testes and are reabsorbed, ejaculation is normal but only contains eminal fluid, new studies indicate it may damage cirulatory syste
control the characteristics displayed ex. insect-human, blond-brunette
Gene populations
All the organisms of a given species found within a specific geographic region
follicular phase
dihybrid cross
a genetic cross in which a 2 pairs of alleles (2 characteristics) are followed from one generation to the next
What were the std's that america was worried about and what is now?
Gonorreah and syphalis used to be, now herpes and AIDS epidemics are of more concern because neither can be cured.
coitus interruptus
removal of penis from the vagina prior to ejaculation: sometimes not easy to do
multiple alleles
some characteristics are determined by 3 or more different alleles
the chance that an event will happen. probability= the number of events that can produce one outcome/ the total number of possible outcomes. examples in notes
lack of dominance
in some cases 2 unlike alleles both express themselves
No two individuals in a deme are exaclty alike, the members of a deme usually resemble each other more closely than members of other demes of the same species because?
1) they are more closely related genetially--breed together more often than with members of other demes 2) exposed to more simular environmental influences---selection pressures.
Gene Frequency
Usually stated mathematically in terms of how often a particular show up in the gametes of a population. It is possible for two demes to hav ehte same gene poool but different gene frequences. VERY IMPORTANT- gene frequencies have nothing to do with dominant or recessive genes. within a gene recessive is found more often then dominant.
selective breeding is usually accomplished by
1) finding wild demes that are homozygous for the desired trait 2) breed small groups to form organisms that are homozygous for desired traits *note it is hard to breed an individual that is homozygous for 2 good traits
Demes exist because of
geographical barriers (mountains, rivers) and environental differences (temp changes with altitude, latitude, light intensity.)
Mendel's law of independent assortment
members of one gene pair seperate from each other independently of the members of other gene pairs
prevention of fertilization
estrous cycle
the rythic changes in the female reproductive tract
What are the 4 functions of seminal fluid
1) vehicle for transport of sperm 2)lubrication of passages, 3) cheical buffer against acids in female genital tract, 4) contains sugar which provide energy
How do homozygous genes and heterozygous genes interact?
often one allele will mask the effect of the other allele for a given trait----dominant allele
The production of eggs

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