Lesson 2 Flashcards
(129 cards)
1
Q
What are the two gametes?
A
The sperm and the egg
2
Q
How are gametes produced
A
Meiosis - specialised cell division
3
Q
What is unique about gametes in terms of chromosomes?
A
Gametes only have half the genetic material compared to other normal cells in the body
4
Q
What is the ration of male to female conception?
A
Approx 120/150 males for every 100 females
5
Q
What is the main theory of the reason why more males are conceived compared to females?
A
Sperm bearing the Y chromosome are lighter so therefore swim faster, compared to the X chromosome
6
Q
Which has a higher rate of miscarriage - male or female embryos?
A
Male embryos
7
Q
What is a zygote?
A
A fertilised egg
8
Q
How many periods are there of prenatal development?
A
Three
9
Q
What is the first period of prenatal development?
A
Germinal
10
Q
What is the germinal stage?
A
Beings with conception - lasts until the zygote becomes implanted in the uterine wall - rapid cell division occurs
11
Q
What is the embryonic stage?
A
Follows implantation - major development occurs in all organs and systems of the body. Development takes place through the process of cell division, cell migration, cell differentiation and cell death, as well as hormone influences
12
Q
What is the fetal stage of prenatal development?
A
Continued development of physical structures and rapid growth of the body, increasing levels of behaviour, sensory experience and learning
13
Q
What are the four major development processes transforming a zygote into an embryo and then fetus - involving cells
A
Cell division
Cell Migration
Cell differentiation
Selective cell death
14
Q
What is the result of cell division?
A
Proliferation of cells
15
Q
What is cell migration?
A
Movement of cells from point of origin to somewhere else
16
Q
What is cell differentiation?
A
Transforming stem cells into 350 different types of cells
17
Q
What is selective cell death also known as?
A
Apoptosis
18
Q
What hormone is involved in the developing of genitalia
A
Prescience or absence of testosterone
19
Q
What is the blastocyst
A
Occurs by fourth day of conception - Zygote rearranges itself into a hollow sphere of cells, the inner cell mass is on one side
20
Q
What does the inner cell mass eventually form?
A
The embryo
21
Q
How do identical twins originate?
A
Splitting in half of inner cell mass
22
Q
How do fraternal twins originate?
A
When two eggs are released into the fallopian tube at the same time
23
Q
What is the neural tube?
A
U-shaped groove formed from the top layer of differentiated cells in the embryo
24
Q
What foes the neural tube eventually become?
A
Brain and spinal cord
25
What does the support system include?
The placenta and the umbilical cord
26
What is the purpose of the placenta
Permits the exchange of materials between the bloodstream of the fetus and that of the mother
27
What is the purpose of the umbilical cord
Contains blood vessels that travel from the placenta to the developing organism and back again
28
What is the purpose of the placental membrane?
Protect against some, but not all, toxins and infectious agents
29
What is the purpose of the amniotic sac?
Membrane filled with fluid which the fetus floats in - it provides a protective buffer for the fetus
30
When does cephalocaudal occur?
From the fourth week onwards
31
What does cephalocaudal mean?
The area near the head develops earlier than those further away
32
How many weeks after gestation will most of the movement present at birth occur?
12 weeks
33
How does swallowing amniotic fluid aid development?
Normal development of the palate and aids in maturation of the digestive system
34
How does the fetus aid the development of the respiratory system and how?
Movement of chest wall and pulling in and expelling small amounts of amniotic fluid
35
When do fetal rest-activity cycles become stable?
2nd half of pregnancy
36
Near the end of pregnancy - the fetus’s sleep and wake states are similar to those of the newborn - true or false?
True
37
Do sensory structures appear early or late in prenatal development?
Early
38
How does a fetus experience tactile stimulation?
Own activity and taste/smell of amniotic fluid
39
At what month of pregnancy does the fetus respond to sound?
6 Months
40
Prenatal vision is good - true or false
False - it is experienced but is negligible
41
How many weeks into gestation does the fetus become habituated to continued/repeated stimulation?
32 weeks
42
What are three examples of fetal learning
Habituation
Recognisition of rhymthes/stories told before birth
Preference of smell, taste and sound patterns due to prenatal exposure
43
What is meant by the term sensitive period
The human brain is particularly sensitive to particular external stimuli
44
What is experience-expectant plasticity?
Process through which the normal wiring of the brain occurs in part as a result of the kinds of general experiences that every human who inhabits any reasonable normal enviroment will have
45
What is meant by the term vulnerability in regards to experience-expectant plasticity?
If the expected experience is not available - development will be impaired
46
Explain experience-dependent plasticity in regards to neurons:
The process through which neural connections are created and reorganised throughout life as a function of an individuals experience
47
Explain experience-dependent plasticity in regards to neurons:
The process through which neural connections are created and reorganised throughout life as a function of an individuals experience
48
What are teratogens?
Environmental agents that have the potential to cause harm
49
What is a crucial factor in regards to the effect teratogens can have on development?
Timing effects severity - some may only cause damage if exposed to during a sensitive period
50
What is a dose-response relation in regards to teratogens
Increase in exposure to teratogens associated with greater defects
51
What can influence teratogens influence?
Individual differences
Dose-response relation
52
What causes an issue in identifying teratogens?
Sleeper effects
53
What is meant by the sleeper effect of a teratogens?
Impact of teratogen may not cause an impact for many years
54
Are all teratogens illegal?
No
55
What can be caused by maternal alcoholism?
Fetal alcohol syndrome (FAS)
56
What are the symptoms of fetal alcohol syndrome?
Mental retardation, facial deformity and other problems
57
How does cigarette smoking affect development??
Reacted growth/low birth weight
58
What teratogens has shown a link to SIDS (sudden infant death syndrome)
Smoking
59
How can the risk of SIDS (sudden infant death syndrome) be reduced?
Not smoking
Sleeping on back
Firm mattresses
No pillows
60
What is meant by state in terms of interaction with the environment?
The level of arousal/engagement in their environment
61
What are the six states of arousal?
Active sleep
Quiet Sleep
Crying
Active Awake
Alert Awake
Dozing
62
How does the length of sleep change from infancy to young adult?
Infants sleep twice as much as young adults
63
What does REM (sleep) stand for?
Rapid Eye Movement
64
Describe REM sleep:
Active sleep state
Associated with dreaming
Characterised by quick, jerky eye movements
65
Describe non-REM sleep:
A quiet/deep sleep
Characterised by absence of motor activity and eye movements
Regular/slow brain waves, breathing and heart rate
66
Explain the percentage change of REM sleep from newborn to 3/4 years old
50% newborn
20% 3/4 year olds
67
What is meant by auto stimulation theory?
Brain activity during REM sleep in the fetus and newborns makes up for the natural deprivation of external stimuli and facilitates the early development of the visual system
68
What does crying reflect in early infancy
Discomfort and frustration
69
Can cry’s have different characteristics?
Yes
70
What is the purpose of crying during later infancy development?
Communication
71
What are effective methods to soothe crying?
Swaddling or other activities involving intense and continuous stimulation
72
What is colic?
Excessive crying for no reason
73
Do risk factors tend to occur alone or together?
Together
74
When does a negative outcome become more likely to occur - in regards to risk factors?
When multiple risk factors occur at the same time
75
What does developmental resilience refer to?
Successful development in the face of multiple and overwhelming developmental hazards
76
How does parenting styles affect resilience in development?
Infant experiemces responsive care from caregiver
77
What are two common personal characteristics that occur in resilient infants?
Intelligence and responsiveness to others
78
By what percentage do humans differ from each other genetically?
Less than 1.5%
79
What are the three key elements of model of interaction?
Genotype
Phenotype
Enviroment
80
Explain genotype in regards to model of interaction:
The genetic material inherited
81
Explain phenotype in regards to the model of interaction:
The observable expression of the genotype - body characteristics and behaviour
82
What is meant by the enviroment in model of interaction?
Includes every aspect of the individual and their surroundings - other than genes
83
What are the four fundamental relations of development?
Parents genetic contribution of child’s genotype
Child’s genotype to their phenotype
Child’s enviroment to phenotype
Influence of phenotype to their enviroment
84
How is genetic material passed on?
Chromosomes - threadlike molecules made of DNA
85
What are genes?
Section of chromosomes that are the basic units of heredity for all living things
86
Do genes code directly for behaviour?
No
87
How do genes affect behaviour?
Genes operate at the level of cells - create biochemical structure and functional differences - effects course of development and the enviroment - act in probabilistic way to guide brain development, behaviours and exposure to enviroment
88
What is an Allele:
Number of alternative forms of the same gene
89
What is a genome?
Total complement of genes in an organism, stored in one or more chromosomes
90
How do genes influence behaviour?
Role in building/modifying physical structure of the body - this structure interacts with the environment - producing behaviour
91
What is the difference between dominant allele and the recessive allele?
Only one dominant allele needs to be present for an expression in the phenotype
92
What is a person with two of the same allele known as?
Homozygous
93
What is the person with two different alleles known as?
Heterozygous
94
How many pairs of alleles do humans have (typically)
23 pairs
95
Chromosomes have corresponding alleles on each chromosome in the pair - true or false?
True
96
What does polygyny mean?
Influences by multiple genes
97
What does pleiotropy mean?
Genes influencing more than one trait
98
What is an example of pleiotropy?
Phenylketonuria - mutation on single gene that codes for the enzyme that converts amino acid phenylalanine to tyrosine
99
How many genetic disorders are known to have genetic origins?
Over 5,000
100
What is an example of a disease caused by a recessive gene?
PKU, Sickle-cell anemia, cystic fibrosis
101
What is an example of a disease/disorder caused by a dominant gene?
Huntington’s disease
102
What is an example of a disease/disorder caused by sex-linked inheritance?
Fragile-X syndrome - FMR1 gene on X chromosome
Haemophilia - Mutation on X Chromosome leading to faulty clotting factors
103
What is an example of a disease/disorder caused by an error in meiosis?
Zygote has less/more chromosomes than normal - can cause Down syndrome/trisomy-21 or Kleinfelter syndrome/XXY
104
What are the benefits and deleterious effects of sickle cell?
Deleterious effects - blood disorder when both alleles are present
Benefits - Protection against malaria - disease can’t take hold
105
In the 23rd pair of chromosomes, what chromosomes are present for females?
Two X chromosomes
106
In the 23rd pair of chromosomes for males, what chromosomes are present?
X and Y
107
Where is the gene located that triggers the formation of the testes, resulting in testosterone
The Y chromosome - on 23rd pair
108
What is the “male disadvantage” in regards to genes/chromosomes?
The Y chromosome only has 1/3 of the amount of genes as the X chromosome
109
Why are males more likely than females to experience inherited disorders?
Alleles found on the X chromosome do not have a responding allele on the Y chromosome that could suppress the action - an example is colour blindness
110
What does multifactorial mean in regards to behavioural genetics?
Affected by enviroment and genes
111
What is “the warrior gene” and explain the study surrounding it:
MAO-A enzyme encoded by MAOA gene. Having two repeats of this gene has an increased likelihood of committing violent acts if exposed to antisocial behaviour.
The repeat of MAOA results in low MAOA activity.
This shows that having HIGH MAO-A activity lessens the effect of abuse/protected against effects of abuse. If low - abuse matters
112
How is a family study carried out?
A trait of interest is measured among groups of people who vary in genetic relation
113
What do family studies aim to achieve/observe?
Correlation between the trait in individuals examined to see if higher with individuals who are genetically similar and/or share the same enviroment
114
What are two examples of family studies?
Twin Studies
Adoption Studies
115
What are twin studies?
Monozygotic twins studies on a trait of interest compared to dizygotic twins
116
What are adoption studies?
Researchers examine whether adopted children are more similar to biological or adoptive relatives
117
What is heritability?
How much variation in a phenotype in a population is due to genetic variation
118
What is the difference between heritability and inherited traits?
Heritability applies to traits that differ between individuals. If a trait is precisely the same, it may be inherited but it cannot be heritable - example is height vs number of eyes
119
What does heritability only apply to?
Population
120
Heritability tells us about an individual - true or false?
False - ONLY POPULATION
For example - shyness heritability of 0.4 tells us that 40% of individual differences that are observed in shyness may be attributed to genes - does not mean 40% due to genes and 60% due to enviroment
121
What does something having a high heritability mean?
Due more so to genetic differences than to environmental diffferences
122
What is the difference between shared and non-shared factors?
Shared - same experiences - such as growing up together in same family
Nonshared - enviroment unique to individual
123
What is the primary effect of nonshared environmental factors?
Individual differences among family members
124
Are neurons all the same?
No - variation reflects diversity
125
What do atoms consist of?
A nucleus containing protons and neutrons
Orbited by electrons
126
Do protons have a positive or negative charge?
Positive
127
Do electrons have a positive or negative charge?
Negative
128
Are the number of protons and electrons equal or unequal?
Equal
129
How are atoms held together?
Electrostatic force
