Week 1
1. What are gametes and what is meiosis, and how do they relate to each other?
Gametes are also called germ cells. They are reproductive cells, so either germ or
sperm cells, that contain only half of the information that other cells in the body
contain. Gametes are produced through meiosis. Meiosis is a form of cell division
in which the egg and sperm cells only receive one member from each of the 23
chromosome pairs.
2. Describe each of the four major developmental processes that underlie the
transformation from zygote to fetus.
The four major developmental processes are cell division, cell migration, cell
differentiation and apoptosis.
Cell division is also known as mitosis. Within about 12 hours after conception, the
zygote divides into two equal parts, each containing a full complement of genetic
material. These two cells then divide into four, those four into eight, those eight
into sixteen, and so on. Through continued cell division over the course of 38
weeks, the barely visible zygote becomes a newborn consisting of trillions of cells.
Cell migration is when cells move away from their point of origin.
Cell differentiation happens when cells acquire their function in the body. Initially,
all the cells are embryonic stem cells, which are cells that can develop into any
type of body cell. After several episodes of division, however, cells start to
specialize.
Lastly, apoptosis is the death of all the cells that are not needed. It is known as
selective cell death or genetically programmed cell death.
3. Why are monozygotic twins genetically more alike than fraternal twins?
By the 4th day after conception, cells arrange themselves like an inner cell mass.
When this splits, genetically identical twins occur.
However, dizygotic twins result much earlier, when two eggs are fertilized into the
fallopian tube. They thus originate from two different eggs and two different
sperm.
4. What happens with the inner cell mass when the zygote becomes an embryo?
During the second week, the inner cell mass folds itself into three layers. The top
layer becomes the outer layer of our body (teeth, skin, nails, etc), the middle layer
, becomes muscles, bones and internal organs, and the third layer develops into the
digestive system, lungs, etc. Shortly after this, the neural tube forms down the
center of the top layer.
5. What does a fetus most likely hear in his mother’s womb? How do we know
this?
The prenatal environment is very noisy. The soundscape consists of the mother’s
heartbeat, blood flow and breathing. We know this because the fetus' heartbeat
rises when the mother speaks. During the last trimester, other external noises can
also have an effect on the heart rate.
6. Why would the effects of teratogens differ when it comes to different periods
of pregnancy? Why can it be difficult to investigate their effects?
Many teratogens are only harmful if they occur only during a certain sensitive
period of the fetus’ development. Because each system and body part develop
during a different time, exposure to a teratogen at 2 months can have very different
effects than exposure at 7 months of pregnancy. In the first months, the central
nervous system and heart and eyes are mostly at risk. In the last months, it is
mostly the ears and external genitalia.
Because teratogens often occur in combination, it is difficult to separate their
effects. However, we know that the presence of multiple risk factors can have a
cumulative harmful effect on development.
7. What is Fetal Alcohol Spectrum Disorder?
Babies born with FAS often have different facial structures and sometimes
attention problems and intellectual disabilities. FAS occurs through maternal
drinking.
8. Name a couple of various teratogens
Opioids. As these are designed to mimic the effects of neurotransmitters, they can
have catastrophic effects on the brain. Babies themselves sometimes also become
addicted
Cigarettes and smoking. When pregnant women smoke, the baby receives less
oxygen. The effects of smoking are greatest in gestation
Environmental polluters.
,9. Why would squeezing/pushing during birth be beneficial for a baby?
Firstly, the squeezing temporarily reduces the overall size of the baby’s head,
making it easier to push out .
The squeezing also promotes a hormone that helps the baby to withstand mild
oxygen deprivation when it is born.
10. What are the universal dual goals of people during childbirth?
Safeguarding the health of the mother and the child
Ensuring the social integration of the baby
11. How did behaviorists view attachment of babies to their mothers? How did
Harlow’s experiment contradict this view?
Proponents of behaviorism argued that food, such as breast milk, is the basis for
the bond. Infants link food to mothers through the process of classical
conditioning, in which food is the unconditioned stimulus that causes the infant to
experience pleasure and mothers are the conditioned stimulus linked with the food.
From a behaviorist perspective, mothers evoke pleasure in the infant only because
of this association
However, Harlow’s experiment using fake ‘mother monkeys’, one of cloth and one
of wire, showed that monkeys often had a strong preference for the cloth mother.
This shows that they needed a certain level of comfort.
12. What are important purposes of attachment?
First, it enhances the infant’s chance of survival by keeping the caregiver (who is
also the source for food and protection) in close proximity. Second, attachment
helps the child feel emotionally secure, which allows the child to explore the
world without fear. Third, it serves as a form of co-regulation that helps children
manage their levels of arousal and their emotions. Bowlby proposed that the
attachment process between infant and caregiver is rooted in evolution and
increases the infant’s chance of survival.
Through the process of attachment, the child develops an internal working model
of attachment, a mental representation of the self, of attachment figures, and of
relationships in general.
, 13. How did Bowbly view attachment?
Bowlby proposed that the attachment process between infant and caregiver is
rooted in evolution and increases the infant’s chance of survival. Just like
imprinting, this attachment process develops from the interaction between
species-specific learning biases.
14. Explain the Strange Situation test of Ainsworth, and the critique some
researchers have on the experiment.
In this test, the child, accompanied by the parent, is placed in a laboratory
playroom equipped with interesting toys. After the experimenter introduces the
parent and child to the room, the child is exposed to seven episodes, including two
separations from, and reunions with, the parent, as well as two interactions with a
stranger—one when the parent is out of the room and one when the parent is
present Throughout these episodes, observers rate the child’s behaviors, including
attempts to seek closeness and contact with the parent, resistance to or avoidance
of the parent, interactions with the parent from a distance using language or
gestures. Particularly important to determining a child’s attachment is his or her
reaction to the parent when that parent returns after the separation.
Depending on how the child reacts, the child is put in one of three categories;
secure attachment, insecure/resistant, or insecure/avoidant. The rest belongs to the
disorganized/disoriented category.
Some critiques are that the experiment required too much of a laboratory setting
and that the attachment of relationships should be measured in multiple
dimensions/continuums. Some people also say that many children are not cared for
by their caregivers in everyday life anyway, as children have increasing contact
with other ‘strangers’.
15. What are some characteristics of sensitive parenting? How does this relate to
attachment styles?
Parental sensitivity involves the expression of warmth as well as contingent and
consistent responsiveness to children’s needs. This includes responding quickly to
the needs of a crying baby, smiling back at a beaming one, and engaging in
positive exchanges. Such parental sensitivity promotes secure attachment.
Parents who were often highly anxious, overwhelmed and inconsistent in their
caregiving usually have more insecure/resistant children.
