The total number of number of chromosomes in a new cell is described as a ______
Diploid (2n)
23 in the sperm +
23 in the egg =
46
true
Meiosis results in ____ daughter cells
4
during meiosis I, homologus chromosomes come together and line up side-by-side, the _______ results in a tertrad, an association of 4 chromatids that stay in close proximity until they seperate
synapsis
Daughter cells from meiosis become gametes
true
Chromosomes occur in pairs, _______ they look alike and carry genes for the same traits
homologous chromosomes
Meiosis I produces _____
2 haploid daughter cells (n)
Meiosis II produces______
4 haploid daughter cells
there are three ways an individual is assured a different combo:
1. crossing over
2. following meiosis, gametes have all possible combos of chromosomes
3. sperm and egg carry verying combos of chromosomes
_________ is the production of sperm: occurs in the testes
Spermatogenesis
_____ is the production of eggs; occurs in the ovaries
Oogensis
Meiosis in males results in ______ that become sperm
4 haploid cells
Meiosis in females results in _____ and ____or _____
1 egg and 2 or 3 haploid polar bodies
Humans have: 46 chromosomes and 23 pairs
22 pairs are ______ - nonsex chromosomes
autosomes
1 pair is the ______ - beucause they differ between sexes
sex chromosomes
Males have a (___) chromosomes
XY
Females have a (____) chromosomes
XX
Any cell in the body, except red blood celss, can be a source of chromosomes for karyotyping
_____ is a procedure for obtaining a sample of a amniotic fluid from the uterus of a pregent wouman: 14th and 17th week of pregnancy
Amniocetesis
_____ is aprocedure for obtaining chorionic cells in the region where the placenta will develop: 5th week of pregnancy
Chorionic Villi Sampling (CVS)
_____ occurs during meiosis I when both members of a homologous pair go into the same daughter cell
Nondisjunction
______ also occurs in meiosis II when the sister chromatids fail to seperate and both daughter chromosomes go intothe same gamete
Nondisjunction
______ (aka trisomy 21) because the individual usually has 3 copies of chromosomes 21
Down Syndrome
A chromosomal delection is responsible for ______
moon shaped face
Cri du Chat Syndrome
A child's sex is determined by the father
______ is when the X is nearly broken, leaving the tip hanging
Fragile X Syndrome
Turner Syndrome
XO
has only one sex chromosomes
Klinefelter Syndrome
XXY
no matter how many X chromosomes are involved. a person with a Y chromosome is a male
Poly-X-Females
XXX
tall and skinny
XXXX
severely reatrded
Jacob Syndrome
XYY
only occur from nondisjunction during spermatogensis
_____ refers to the genes of an individual
Genotype
Upercase letter; always win
Dominant allele
Lowercase letter
recessive allele
Alternate forms of a gene having the same position on a pair of chromosomes and affect the same trait
Alleles
____ is the physical appearance of the genes
Phenotype (unattached)
______ is EE, two of the same dominant allele; phenotype displayed is diminant
Homozygous dominant
_____ is ee; two of the same recessive allele; phenotype displayed is recessive
Homozygous recessive
_____ is Ee; one dominant allele and one recessive allele; phenotype displayed is dominant
Heterozygous
EE Ee ee
attached, unattached
Genotype
Phenotype
A _______ is used to determine the phenotypic ratio among the offspring when all possible sperm are given a chance to fertilize all possible eggs
Punnett square
_____ occurs when one trait is goverened by 2 or more sets of alleles
the effects are also additive
the results is a continuous variation of phenotypes
Multifactoral inheritance
Environmental influences example is ______
Himalayan Rabbits
_____ occurs when alleles are equally expressed in a heterozygote; blood type and skin color are examples
Codominance
______ is exhibited when they heterozygote has an intermediate phenotype between that of either homozygote; hair is an example
Incomplete dominance
Blood type is determined by _________
multiple alleles
AA
AO
Type A blood type
BB
BO
Type B blood type
OO
Type O blood type
A male always receives a sex-linked trait from his mother
When he inherited the X chromosome
Genetic counselors often construct _____ to determine whether a disorder is dominant or recesive
Pedigree Charts
_____ is disease that results from a lack of _____ enzyme Hex A
Tay-Sachs
Lysosomal
Lysosomes fill to capacity with ______ that cannot be broken down, the cells become so full that the child dies
Macromolecules
______ is when mucus in the bronchial tubes and pancreatic ducts is very thick and viscous
Cystic Fibrosis
Research shows Cl- ions fail to pass through plasma membrane channel proteins in cells in ______
Cystic Fibrosis
_____ individuals lack an enzyme that is needed for the normal metabolism of the amino acid phenylalanine
abnormal breakdown product, phenylketone accumulates in the urine
Phenylketonuria (PKU)
small benign tumors called neurofibromas that arise from the fibrous coverings of nerves develop
Gene 17 controls the productions of protein called neurofibromin that normally blocks growth signals leading to cell division
Neurofibromatosis
______ is the neurological disorder that leads to progressive degeneration of brain cells. that in turn causes severe muscle spasms and personality disorders
Huntington Disease
______ is this disorder is controlled by incompletely dominant alleles
Sickle Cell Disease
If a male has an X-linked recessive condition his daughter are _______ - appear normal but can pass on allele for a genetic disorder
Carrier
Recessive alleles on the X chromosomes are always expressed in males since Y chromosome does not have a corresponding allele
Color blind people were used during the wars as a benefit to spot camoflauge camps
______ is characterized by a wasting away of the muscles
Muscular Dystrophy
The recessive allele is remains in the population through passage from carrier mother to carrier daughter
Muscular Dystrophy
Hemophilia A-absence of clotting factor VIII
Hemophilia B-absence of clotting factor IX
_____ consist of the brain and spinal cord
Central Nervous System (CNS)
______ consists of nerves that carry info to the CNS
Peripheral Nervous System (PNS)
______ support and nurish neurons
Neurogila
There are three classes of neurons:
1. Sensory neurons
2. Interneurons
3. Motor neurons
_____ take nerve impulses to the CNS
Sensory neurons
_____ sum up nerve impulses recieved from sensory neurons before relaying with motor neurons
Interneurons
_____ take nerve impulses away from the CNS to effectors
Motor neurons
______ carry out our responses to environmental changes
Effectors
_____ contains the nucleus and organelles
A cell body
_____ receive signals
Dendrites
____ conducts nerve impulses
Axon
A type of neurogilia called ______ form the myelin sheath
Schwann cells
_____ means the axon is NOT conducting an impulse
Resting potential
A membrane protein that actively transports Na out and K into the axon
Distribution of ions is due to a sodium-potassium pump
_____ means the axon is conducting an impulse
Action potential
during depolarization Na moves inside the axon
during repolarization K moves outside the axon
As soon as an action potential moves on, the previous portion undergoes a ______- during which the Na gates are unable to open
refractory period
this ensures the action potential only moves forward
A ____ is a gap between neurons
Synapse
Transmission across a synapse is carried out by _______
neurotransmitters
ACh and NE are the most well known neurotransmitters
Each portion causes an action potential in the next portion of an axon
Both the spinal cord and brain are protected by bone and _______
meninges (protective membranes)
Spaces between the meninges are filled with ______ which cushions and protects the CNS
Cerebrospinal fluid
Composed of two types of nervous tissue
1. Grey matter- cell bodies and nonmyelinated fibers
2. White matter- myelinated axons
____protects the spinal cord
Vertebrae
The function of the spinal cord
means between the brain and the body
also a center for reflex actions
The _____ is the largest portion of the brain
Cerebrum
_____ is a region of the brain that accounts for sensation, voluntary movement and thought process associated with consciousness
Cerebral Cortex
_____ is the frontal lobe; voluntary commands to the skeletal muscles begin here
Primary motor area
______ is the parietal lobe; sensory info from the skin and skeletal muscle arrives here
Primary somatosensory area
_____ is a motor speech area in the left frontal lobe
Broca's area
_____ helps maintain homeostasis by regulating hunger, sleep, thirst, body temp and H2O balance
Hypothalamus
_____ serves as a link between the nervous and endocrine systems
Hypothalamus
______ receiving end for all sensory input except smell; also invovled in memory and emotions
Thalamus
______ recieves sensory input from the eyes, ears, joints, and muslce about the present position of the boyd parts
______ assists in the learning of new motor skills
Cerebellum
Cerebellum
The brain stem contains:
midbrains
pons
medulla oblongata
_____ has reflex centers for visual, auditory and tactile responses
Midbrain
_____ helps regulate breathing rate and has reflex centers concerned with head movements
Pons
_____ contains reflex centers for regulating heartbeat, breathing, and blood pressure, vomitng, coughing, sneezing, hiccupping, and swallowing
Medulla oblongata
Reticular activating system causes a person to be alert
____ in the temperal lobe; makes the prefrontal area aware of past experiences
Hippocampus
_____ can cause past experiences to have emotion
Amygdala
Learning takes place when we retain and utillize past memories
____ are a budle of axons called nerve fibers
Nerves
The PNS is divided into the somatic system and the autonomic system
______ serves the skin, skeletal muscles and tendons
Somatic System
Involuntary reflexes allow to respond rapidly to external stimuli
______ regulates the activity of cardiac and smooth muscle and glands
Autonomic
The system is divided into the symathetic and parasympatetic
1. the function automatically and usually in an involuntary manner
2. they innervate all internal organs
Sympathetic division brings about responses associated with fight or flight
it accelerates the heartbeat and dilates the bronchi
inhibits the digestive tract
primarily releases the neurotransmitter NE
_____ brings about the responses associated with a relaxed state
Parasympathetic division
Drug usually have two effects
1. they impact the limbic system
2. either promote or decrease the action of a particular neurotransmitter
____ is used as an energy source, and as such will decrease the rate at which we burn fat for energy
Alcohol
In the CNS _____ causes neuorns to release dopamine
Nicotine
_____ prevents uptake of dopamine causing the user to experience a rush sensation
Cocaine
_____ binds to receptors meant for the endorphins
Heroin
_____ binds to a receptor for anadamide
Marijuana
_____ attaches to dopamine and NE receptors, hinders reuptake
_____ reverses effects of fatigue
Methamphetamine
_____ is the gradual loss of reason that begins with memory lapses and ends with the inability to perform daily activties
Alzheimer disease
During Alzheimers Disease the neurons have 2 abnormalities
1. plaques envelope the axon
2. neurofibrillary tangles are in the axons
During _____, the basil nuclei are overactive because of degeneration of dopamine-releasing neurons
Parkinson disease
The male gonads are the _____ which are located in the _______
testes
scrotum
The testes produce ____
sperm
Sperm mature in the ______ and then move to the _______
Epididymis
Vas deferens
3 structures add secretions to seminal fluid:
1. Seminal vesicles: at base of bladder
2. prostate gland: surrounds the urethra
3. bulbourethral glands: organs lie posterior to prostate
Each component of seminal fluid is required for a particular function
1. Seminal fluid has a basic pH: sperm is viable in basic solution
2. Seminal fluid contains fructose: sperm need energy
3. Semen also contains prostaglandins: uterus to contract
During sexual arousal ______ is produced and erectile tissue fills with blood
cGMP
Sperm counts can be low and still achieve fertilization
true
The testes lie outside the body cavity within the _____
scrotum
____ is the inability to produce offspring
Sterillity
The internal temperature of the body is too high to produce viable sperm
true
The scrotum helps regulate the temperature of the testes
Mature sperm has three distinct parts
Head
Middle piece
Tail
The ______ contains the mitochondria of the sperm
Middle piece
emergy movement of the tail
The ____ contains an acrosome of the sperm
Head
stores enzymes needed to penetrate the egg
In males the _____ promotes production of sperm
FSH (follicle-stimulating hormone)
In males the _____ controls the production fo testosterone
LH (luteinizing hormone)
_____ is the main sex hormone in males
Testosterone
_____ is essential for normal development; brings about and maintains the male secondary sex caracteristics
Testosterone
The female gonads are the _____
ovaries
____ is the process by which an egg burst from an ovary
Ovulation
The oviducts have fingerlike projections called _____
Fimbriae
The ____ is a thick-walled muscular oragan
Uterus
Fertilization usually takes place in the _____
Oviduct
_____ is when the embryo embeds into the prepared uterine lining
Implantation
_____ is collectively known as the vulva
External genitalia
The ____ is the organ of the sexual arousal and contains erectile tissue
Clitoris
Ooctes are present at birth, so they age with the female
true
During the _____ phase- FSH promotes the development of a follicle in the ovary-secretes estrogen
Follicular phase
During the _____phase-LH promotes the development of the corpus luteum-secretes progesterone
Luteal phase
As the luteal phase comes to an end, menstruation occurs
Day ___: ovulation occurs
14
Estrogen and Progesterone:
1. shut down anterior pituitary
2. maintain the endometrium
3. responsible for secondary sex characteristics
______ is a small piece of molded plastic that is inserted into the uterus by a physician
IUD (Intrauterine device)
_____ is a latex cup that lodges behind the pubic bone and sits over the cervix
Diaphragm
_____ uses synthetic progesterone to prevent ovulation
Contraceptive implants
_____ is the failure of a couple to achieve pregnancy after 1 year of regular, unprotected intercourse
Infertility
The most common causes of infertility in females the most common causes are blocked oviducts, endometriosis and weight
_____ is the presence of uterine tissue outside of the uterus in the oviducts and on the abdominal organs
Endometriosis
In males the most frequent causes of infertility is low sperm count and/or a large proportion of abnormal sperm
A variation of AID is intrauterine insemination (IUI)
During meiosis I the _____ line up during a process known as synapis
Homologous chromosomes
How many daughter cells are present at the end of meiosis II?
4
In what ways can meiosis assure new genetic combinations occur in offspring?
Crossing-over
Gametes have different combinations of chromosomes that parent cells
Recombintion of chromosomes occurs during fertilization
What is the nature of the daughter cells following meiosis II?
4 haploid (n) cells
Oogenesis results in the production of _____
1 haploid (n) egg cell, 2-3 polar bodies
The correct number of chromosomes found in a gamete (egg or sperm) is _______?
23
_____ is a procedure for obtaining a sample of amniotic fluid from the uterus of a pregnant woman, which increase the risk for spontaneous abortions by about .3%
Amniocentesis
An abnormal chromosome makeup in an individual can be due to nondisjunction which can occur during ______
meiosis I
meiosis II
The sex chromosomal genetype of an individual who has Turner syndrome is ______; these females have underdeveloped ovaries, do not undergo puberty, and have only one sex chromosomes.
XO
______ refers to the genes of an individual.
Genotype
A recessive allele must be received from both parents to bring about on autosomal recessive phenotype.
true
Multifactorial inheritance has an additive effect that results in a continuous variation of phenotypes.
True
In Tay-Sachs disease, individuals lack the enzyme Hex A, and their lysosomes fill to capacity with ____ that cannot be broken down resulting in death.
Macromolecules
More males have X-linked recessive disorders because the Y chromosome lacks the corresponding allele.
true
A myelin sheath is formed when Schwann cells wrap pieces of their plasma membranes around an axon
True
_____ is found in the frontal lobe and is the origination point of voluntary commands sent to the skeletal muscles.
Primary motor area
The ____ is found within the limbic system and causes the prefrontal area to be aware of past experiences.
Hippocampus
Nicotine is quickly delivered to the nervous system where it causes neurons to release ______
Dopamine
Basal nuclei that become overactive because of degerneration of dopamine-releasing neurons are characteristic of which of the following neurodegenerative disorders?
Parkinson's
Aside from energy, sugar, and a basic pH, seminal fluid also has ______ which causes uterine contractions, possibly aiding the journey of sperm cells to the egg.
Prostaglandins
The normal site of fertilization within the female body is the _____
oviducts
During the _____ phase, follicle stimulating hormone (FSH) promotes the development of a follicle inthe ovary which secretes estrogen and progesterone.
Follicular
Estrogen and progesterone _______
Shut down the anterior pituitary preventing further follicle development
Maintain the endometriem for the implanted embryo
Are responsible for secondary sex characteristics and breast development
An IUD is inserted into the _____ and is believed to alter the environment so that fertilization will not likely occur