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Ch.21/MED 127

Human Development and Genetics

The period from fertilization of the egg(zygote) until birth is called? Gestation
Gestation lasts for? 40 weeks
When ONE of the millions of sperm joins the egg to combine DNA and for a zygote is called? Fertilization
ONE of the millions of sperm joins the egg to combine DNA and form a? Zygote
A change or maturation of the sperm that takes place as it is swimming through the uterus is called? Capacitation
What part of the sperm that becomes more fragile is the? Acrosome
Capacitation allows acrosome to burst and digest the? Egg cell membrane
Once a sperm enters the egg, the membrane changes to block another _________ from entering? Sperm
Nuclei fuse restoring the ______number? diploid
How many pairs of autosomes are there? 22
How many sex chromosomes are there? 1 pair
XX = ? Female
XY = ? Male
Mitotic dividing of the zygote is? Cleavage
What consists of 16 cells? Morula
The point when the mass becomes hollow is called? Blastocyst
What is the hollow space filled with fluid? Blastocoele
What is the outer layer of the blastocyst called? Trophoblast
What is the inner layer of the blastocyst? Inner cell mass
Bonding of zygote to the uterine wall 5-8 days after fertilization is called? Implantation
How many stages occur during implantation? 4
During stage 1 of implantation, endometrium produces? Carbohydrates
What stage of implantation does surface proteins on the blastocyst combine withe the carbohydrates? Stage 2
During stage 3 of implantation, trophoblasts secrete? Enzymes
Trophoblast secretes enzymes that digest the surface of the? Endometrium
What happens during stage 4 of implantation? Blastocyst sinks into the crater
What is the embryonic membrane that forms the fetal portion of the placenta? Chorion
Chorion originates as the? Trophoblast
What type of cells are in the inner cell mass? Embyonic stem cells
Can all DNA(genes) can be expressed? Yes
As mitosis continues, certain genes get switched off, others will be? Expressed
There are how many kinds of cells at birth? 200
What is the developing human from implantation to 8th week? Embryo
What are the plate of cells within the blastocyst? Embryonic disc
The 3 germ layers include? Ectoderm, Mesoderm, Endoderm
The outer germ layer is? Ectoderm
The Ectoderm includes? Epidermis and its derivatives, nervous system, lens, cornea, internal ear
The middle germ layer is? Mesoderm
The Mesoderm includes? Dermis, bone, cartilage, muscle, kidneys, blood
The inner germ layer is? Endoderm
The Endoderm includes? GI mucosa, respiratory mucosa, liver, thyroid, pancreas
What gives rise to the first blood cells and sex stem cells? Yolk sac
The yolk sac becomes part of the? Umbilical cord
Thin membrane that surrounds the embryo (amniotic sac)? Amnion
The amnion contains? Amniotic fluid
Amniotic fluid contains? Urine, sloughed off cells
What is a sampling of amniotic fluid? Amniocentesis
What the trophoblast is called as it develops? Chorion
Projections from the chorion into the endometrium that become the fetal part of the placenta? Chorionic Villi
The embryo takes form with head and limbs and beating heart at ____ weeks? 4-5 weeks
The organ systems are established at ____ weeks? 8
Fetal growth occurs during? 9th - 40th week
The maternal and fetal tissue structures that separates fetal and maternal blood is called? Placenta
The placenta is formed by the _____ week 12th
What is a 7 inch diameter flat disc? Placenta
The placenta produces ________ to maintain pregnancy? Hormones
What is hCG? human Chorionic Gonadotropin
hCG is produced by the? Chorion of embryo
hCG stimulates corpus luteum to secrete? Estrogen and progesterone
The corpus luteum secretes estrogen and progesterone to prevent? Uterine contractions
hCG is excreted in? Urine
Progesterone and estrogen inhibit? FSH, LH, and further ovarian follicle development
Progesterone and estrogen prepare? Mammary glands
What inhibits uterine contractions? Relaxin
Relaxin permits stretching of? Pubic symphysis and ligaments
Chorionic villi project into? Maternal blood sinuses
O2, CO2, nutrients and waste products diffuse or are transported across? Maternal blood sinuses
Placenta birthed after fetus is called? Afterbirth
Connects fetus to placenta? Umbilical cord
Transfers blood back and forth? Umbilical cord
There are ____ arteries going ______ from fetus? 2, away
There is ____ vein going ______ fetus? 1, toward
Parturition means? Birth
Sequence of events that occur during birth? Labor
Dilation and effacement of the cervix occurs during which stage? First
Amniotic sac breaks during which stage? First
Mucus plug released during which stage? First
Parturition occurs during which stage? Second
Secreted from posterior pituitary to increase uterine contractions? Oxytocin
What is breeched? Head up
Surgical removal of fetus? Caesarian section (C-section)
Delivery of the placenta occurs during which stage? Third
As soon as birth occurs the fetus is called? Infant
Stimulates medulla which starts respiration? CO2
Breathing promotes pulmonary circulation which closes the? Foramen ovale
After birth, what begins to constrict over next 3 months and 3 weeks? Ductus arteriosus and ductus venosus
May occur as liver immaturity does not excrete bilirubin well? Jaundice
Genetics is the study of? Inheritance
Most of our characteristics are determined or influenced by? Genetics
Our genetics contain? Chromosomes and genes
What is the hereditary material? DNA
DNA is a? Double strand of nucleotides twisted into a double helix
DNA is made up of? A,T,C,G
The entire genetic code is called? Genome
The genetic code for one protein is called a? Gene
Each amino acid comes from a triplet of 3 bases called a? Codon
100 Amino Acids = 100 codons
100 codons = 30 bases
What occurs in the ribosomes? Protein synthesis
DNA -> mRNA is called? Transcription
What is a mirror image of DNA made in the nucleus? mRNA
mRNA leaves the nucleus and attaches to the? Ribosome
mRNA -> protein (via tRNA) is called? Translation
tRNA attaches to the? mRNA
tRNA attaches to the mRNA at a site called the ______ complimentary to the __________? Anti-codon, codon
tRNA picks up the corresponding amino acid and forms? Peptide bonds
tRMA picks up the corresponding amino acid and forms peptide bonds to make a? Protein
DNA -> mRNA -> tRNA -> ? Protein
If a gene's information is used for something such as making a protein it is said to be? Expressed
The genetic code for one protein is called a? Gene
A gene is the genetic code for? One protein
A human cell contains ______(number) chromosomes? 46
22 of the 46 chromosomes are called? Autosomes
A human cell contains 22 pair of autosomes and? 1 pair of sex chromosomes
The sex chromosome in women are called? XX
The sex chromosome in men are called? XY
Homologous chromosomes are a pair of chromosomes that may also be called? Maternal and paternal
The two members of a homologous pair of chromosomes have genes for? The same traits
The possibilities for the expression of a gene are called? Alleles
A person who has two similar genes for a particular trait is called? Homozygous
A person who has two different genes for a particular trait is called? Heterozygous
The genes a person has for a particular trait are called the? Genotype
The expression of the genes a person has for a particular trait is called the? Phenotype
A person's genotype for a particular trait refers to the? Genes that are present
A person's phenotype for a particular trait refers to the? Appearance of the trait; Expression of the gene
If a trait may appear in a person's phenotype when only one gene is present for it, the trait is called? Dominant
if a trait may appear in a person's phenotype only when two genes are present, it is called? Recessive
For the ABO blood types in people, the O allele is? Recessive
For the ABO blood types in people, the A and B alleles are? Co-dominant
The genes for sex-linked traits are found on the? X chromosome
The actual physical genetic makeup, i.e., the sequence of bases on the DNA is called? Genotype
The appearance of how the alleles are expressed is called? Phenotype
Sex linked traits are also known as? X-linked
What factors are also important in determining phenotype? Environmental factors
Approximately how many human genes do we have? 20,000-25,000
What is the human genome project? Every gene has been mapped
What are diseases that are a result of malfunctioning DNA? Genetic diseases
Sex linked traits are recessive, but always expressed in males because? There is no dominant gent to suppress its expression
Sex linked traits are only expressed if females are? Homozygous recessive
A carrier is a? Heterozygous female
When a zygous undergoes cleavage, the process of cell division is? Mitosis
A zygote begins a series of cell division called? Cleavage
The early embryonic stage is a solid sphere of cells is the? Morula
The early embryonic stage that is a hollow sphere of cells with an inner cell mass is the? Blastocyst
The part of a blastocyst that secretes enzymes to permit implantation is the? Trophoblast
Normal implantation of a blastocyst takes place in the? Endometrium of the uterus
In the embryo, the 3 germ layers, or primary layers, are the? Ectoderm, mesoderm, endoderm
In the embryo, the epidermis and nervous system are derived from the? Ectoderm
In the embryo, the bones and muscles are derived from the? Mesoderm
In the embryo, the liver and lungs are derived from the? Endoderm
In the placenta, oxygen and carbon dioxide move by the process of? DIffusion
Created by: laceylake



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