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125 Cards in this Set
- Front
- Back
What is a Chromosome? |
A threadlike structure of nucleic acids and proteins in the nucleus |
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What information does a chromosome contain? |
Genetic information |
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From where do you get your chromosomes? |
Half from mother and half from father |
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What is a gene? |
Physical and functional unit of hereditary |
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What is an allele? |
Alternative forms of a gene |
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What is a dominant trait? |
A trait that will appear in the offspring if one parent contributes it |
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What is a recessive trait? |
Carried in a person's genes without appearing in that person |
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What is a genotype? |
Alleles individual receives at fertilization |
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What is a phenotype? |
Physical appearance of individual |
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What did Watson and Crick contribute to our knowledge of DNA? |
Built a DNA model and suggested how replication works, won the Nobel Prize |
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What is the structure of DNA? |
A double helix, like a twisted ladder |
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How are the sides held together in DNA? |
Deoxyribose sugar and phosphate molecules are bonded |
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How are the "rungs" of the ladder held together in DNA? |
By the bases |
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What is DNA replication? |
Process of copying DNA before cell division |
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Why is DNA replication known as a semiconservative process? |
Each new DNA molecule is made of one parent strand and one new strand |
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Why does DNA replication in eukaryotes start at multiple points along the DNA strand? |
To form "replication bubbles" |
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What are three differences between DNA and RNA? |
1- DNA contains thymine while RNA contains uracil 2- DNA is usually double stranded and RNA is usually single stranded 3- In DNA the pentose sugar is deoxyribose and RNA is ribose |
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Messenger RNA (mRNA) |
Carries genetic message to ribosomes |
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Transfer RNA (tRNA) |
Transfers amino acids to ribosomes, only 1 each |
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Ribosomal RNA (rRNA) |
Joins with proteins to form ribosomes |
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Generally, what is transcription? |
DNA serves as a template to make mRNA |
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Where does transcription occur? |
The nucleus |
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What is the template in transcription? |
DNA |
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What is being transcribed in transcription? |
DNA to RNA |
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Generally, what is translation? |
mRNA directs sequence of amino acids in the protein |
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Where does translation occur? |
Protein synthesis |
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What is the template in translation? |
mRNA |
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What is being translated in translation? |
Amino acids brought in by tRNA |
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What is a codon? |
3 nucleotide sequence in mRNA |
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Where is the anticodon found? |
On molecules of tRNA |
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What is the function of tRNA? |
Helps decode mRNA sequence into a protein |
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What is a mutation? |
Change in the sequence of the bases in a gene |
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How would a mutation affect the DNA, RNA, and protein formation? |
-sickle cell disease -extra or missing nucleotides -all downstream codons affected |
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What is a transgenic organism? |
An organism that have altered genomes, "genetic engineering" |
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What are the two major functions of meiosis? |
1- reducing chromosome number 2- shuffling chromosomes in the cell to produce genetically different combinations |
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What are homologous chromosomes? |
Members of a pair of chromosomes |
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What are sister chromatids? |
One half of the duplicated chromosome |
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What are diploid cells? |
Complete set of necessary chromosomes, 46 |
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What are haploid cells? |
One complete set of chromosomes, 23 |
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When does DNA replication occur? |
During prophase I |
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What is crossing over? |
The exchange of genes between homologous chromosomes |
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Prophase I |
Chromosomes condense, the nuclear envelope breaks down, crossing-over occurs |
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Metaphase I |
Pairs of homologous chromosomes move to the equator of the cell |
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Anaphase I |
Homologous chromosomes move to the opposite poles of the cell |
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Telophase I |
Chromosomes gather at the poles of the cell, the cytoplasm divides |
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Prophase II |
A new spindle forms around the chromosomes |
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Metaphase II |
Chromosomes line up at the equator |
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Anaphase II |
Centromeres divides, chromatids move to the opposite poles of the cells |
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Telophase II |
A nuclear envolpes forms around each set of chromosomes, the cytoplasm divides |
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What is the end result of meiosis? |
4 daughter cells are produced |
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What is nondisjunction? |
Meiosis I- when both members of a pair go into the same daughter cell Meiosis II- when sister chromatids fail to separate |
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Male Reproductive System |
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Ureter Function |
A tube that carries urine from the kidney to the urinary bladder |
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Vas Deferens Function |
Transports mature sperm to the urethra |
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Seminal Vesicle Function |
Secrets a thick, viscous fluid containing nutrients for sperm |
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Ejaculatory Duct Function |
Combines stored sperm with seminal fluids and then transports them to the prostate |
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Prostate Glad Function |
Secretes milky alkaline fluid believed to activate sperm, may become enlarged in older men |
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Bulbourethral Gland Function |
Mucous secretions with a lubricating effect |
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Urethra Function |
Tube that carries urine from the bladder to outside the body and ejaculates sperm when the man reaches orgasm |
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Epididymis Function |
Stores and transports sperm from the testes |
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Foreskin Function |
Covers the elongated shaft during erection, other times protects the sensitive glans penis |
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Penis Function |
Sex organ, acts as conduit for urine to leave the body |
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Testes Function |
To produce sperm and adrogens, mostly testosterone |
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What are the testes composed of? |
Lobules each containing 1-3 seminiferous tubules |
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Which cells undergo spermatogenous? |
Cells in seminiferous tubules |
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What hormone is responsible for sperm production? |
Follicle-stimulating hormone (FSH) |
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Seminiferous Tubules |
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What are secondary sex characteristics? |
Features that appear at sexual maturity Ex: height; broad shoulders; long legs; deep voice; pattern of hair on face, chest, and other regions; muscle development |
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Female Reproductive System |
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Oviduct (Fallopian Tubes) Function |
Links the ovary to the uterus which the ovulated oocyte travels down to become fertilised by sperm |
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Ovary Function |
1- produce oocytes (eggs) for fertilisation 2- produce reproductive hormones, oestrogen and progesterone |
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Uterus Function |
Nurturing the fertilized ovum that develops into the fetus and holding it till the baby is mature enough for birth |
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Fimbriae Function |
Catch the released egg and help move it down into the fallopian tube |
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Cervix Function |
To allow flow of menstrual blood from the uterus into the vagina and direct the sperm into the uterus during intercourse |
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Vagina Function |
Receives the penis during sexual intercourse and also serves as a conduit for menstrual blood flow from the uterus, baby also passes through it during childbirth |
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Vulva Parts |
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What is the primary follicle? |
An immature follicle consisting of an oocyte surrounded by a single layer of tall, supporting granulosa cells |
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What is ovulation? |
Release of secondary oocyte surrounded by follicle cells |
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What is the corpus luteum? |
Follicle that has ovulated and lost its oocyte |
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Ovarian Cycle and Oogenesis |
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What happens during the follicular phase of the ovarian cycle? |
FSH promotes development of follicles, follicle secretes estrogen, blood estrogen levels rise, estrogen inhibits FSH, ovulation ends the follicular phase |
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What happens during the luteal phase of the ovarian cycle? |
LH promotes development of corpus luteum, corpus luteum secretes progesterone, as progesterone levels rise LH levels drop, corpus luteum degenerates if fertilization does not occur |
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FSH Function |
it stimulates the growth of ovarian follicles in the ovary before the release of an egg from one follicle at ovulation |
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LH Function |
Female- it triggers ovulation and development of the corpus luteum Male- it stimulates production of testosterone |
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Estrogen Function |
Female- development of female secondary sexual characteristics Male- helps in maturation of the sperm and maintenance of a healthy libido |
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Ovarian and Menstrual Cycles |
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Hormone Pill |
combination of estrogen and progesterone shuts down production of LH and FSH so no follicles develop |
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Hormone Implant |
synthetic progesterone prevents ovulation by disrupting ovarian cycle |
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NuvaRing |
small flexible piece of plastic that is inserted into the vagina once a month |
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IUD |
fertilization will likely not occur and implantation cannot take place |
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Condom |
Female fits into cervix Male- better when combined with spermicide |
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Diaphragm |
Latex cup covering cervix |
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Sterilization |
a procedure that closes or blocks your fallopian tubes so you can't get pregnant |
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Abstinence |
Very reliable and prevents sexually transmitted diseases (STDs) |
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Genital Warts |
Caused by human papillomaviruses (HPVs), most common |
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Genital Herpes |
Painful genital blisters that rupture leaving ulcers |
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Hepatitis |
Infection of liver A- usually drinking contaminated water, but can be sexually transmitted B- spread same way as AIDS C- contact of blood from inected person |
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Chlamydia |
Causes cervical ulcerations, risk of pelvic inflammatory disease |
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Gonorrhea |
Thick, greenish-yellow urethral discharge Tubes may be blocked by scar tissue |
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Syphilis |
3 stages seperated by latent periods Last stage can affect cardiovascular and/or nervous systems |
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Trichanomiasis |
Caused by flagellated protozoan Trichomonas vaginalis |
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Yeast Infection |
Normally found in vagina, caused by candida |
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How does HIV cause AIDS? |
It attacks the immune system destroying CD4 positive T cells, a white blood cell that fights off infection |
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What are the 3 stages of AIDS? |
A- about 1 year; no symptoms but can spread B- 6-8 years; weight loss, fatigue, fever, diarrhea; thrush and herpes recur C- full-blown AIDS; nervous disorder, opportunistic infections; without intensive treatment, patient dies in 7-9 years |
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What are two big reasons for getting annual STD checks? |
1- to stop or cure it at an early stage 2- to make sure you are safe just in case |
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What is in-virto fertilization? |
-Immature eggs taken to maturity in lab dish -sperm added for fertilization -embryos transferred to woman in secretory phase of menstrual cycle -excess embryos my be frozen |
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Extraembryonic Membranes |
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What is fertilization? |
Results in a zygote, requires sperm and secondary oocyte to interact |
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How do the sperm penetrate the zona pellucida? |
Acrosomal enzymes from sperm digest through zona pellucida |
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During which time in pregnancy does early embryonic development occur? |
First 2 months |
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Where does the early embryonic development occur? |
6 days of development occur in the oviduct before embryo implants in the uterus |
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What is cleavage? |
Cell division without growth |
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What is an early blastocyst? |
-Fluid- filled cavity -Inner will be embryo -Outer will be part of the placenta |
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What is secreted after the blastocyst implants? |
Human chorionuc growth hormone (hCG) |
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What is gastrulation? |
3 layers of cells develop- embryonic germ layers |
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What are the three embryonic layers? |
-Ectoderm- outer layer -Mesoderm -Endoderm- inner layer |
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What do the the three embryonic layers become in adults? |
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From what layer does the nervous system arise? |
Ectoderm (outer layer) |
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What happens to the embryo at 5 weeks? |
Has limb buds |
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What happens to the embryo at 6-8 weeks? |
-remarkable external appearance change -recognizable human -reflex reaction |
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At what time during pregnancy does the embryo develop into the fetus? |
3rd to 9th month |
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Generally, what happens during fetal development? |
-extreme increase in size -geneitalia appear -hair and nails appear |
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What is the function of the placenta? |
-Carbon dioxide and waste move from fetal side to maternal side -nutrients and oxygen move from maternal to fetal side |
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What causes the uterus to contract during labor and birth? |
The hypothalamus cause the pituitary to stimulate the adrenal cortex to secrete androgens |
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Three stages of birth |
1- cervix dilates and amnion bursts 2- baby is born and umbilical cord is cut 3- placenta is delivered |