Chapter 2 101D

Question 1

How many chromosomes do humans inherit from each parent?
A. 23 total
B. 23 pairs
C. 46 pairs
D. 23 individual chromosomes

Answer 1

D. 23 individual chromosomes
Explanation: Each parent contributes 23 individual chromosomes, resulting in 46 total chromosomes in the child

Question 2

How does a baby inherit its unique combination of DNA?

A. Through random mutations during development.
B. By inheriting one chromosome of each pair from each parent.
C. By receiving identical chromosomes from both parents.
D. By inheriting all 46 chromosomes from one parent.

Answer 2

B. By inheriting one chromosome of each pair from each parent.

Explanation: Each parent provides one chromosome from their 23 pairs, combining to form the child’s unique genetic makeup
.

Question 3

What is the genotype?
A. An organism’s observable physical characteristics.
B. The combination of genes an organism inherits from its parents.
C. The RNA surrounding the genes.
D. The environmental influences on an organis

Answer 3

B. The combination of genes an organism inherits from its parents.
Explanation: The genotype is the genetic makeup or combination of alleles an organism inherits.

Question 4

What is the phenotype?
A. The genes an organism carries.
B. The physical expression of an organism’s genetic makeup.
C. The chromosomes passed down from parents.
D. The epigenetic modifications of DNA.

Answer 4

B. The physical expression of an organism’s genetic makeup.
Explanation: Phenotype refers to observable traits, such as eye color or height, which result from the genotype and environmental factors.

Question 5

What role does epigenetics play in gene expression?
A. It determines the exact DNA sequence of an organism.
B. It influences how RNA surrounding genes modifies phenotypes.
C. It eliminates the need for environmental factors in development.
D. It only affects inherited genetic disorders.

Answer 5

B. It influences how RNA surrounding genes modifies phenotypes.
Explanation: Epigenetics studies how environmental factors and “non-junk” RNA can affect the expression of genes without altering the DNA sequence.

Question 6

Which of the following is true about inherited genetic disorders?
A. All genetic disorders are dominant.
B. Most are recessive and require genes from both parents to be expressed.
C. They cannot be passed down from parents.
D. They only occur due to environmental factors

Answer 6

B. Most are recessive and require genes from both parents to be expressed.
Explanation: Recessive genetic disorders require two copies of the faulty gene (one from each parent) for the disorder to manifest

Question 7

How can environmental factors influence genes through epigenetics?
A. They directly change the DNA sequence.
B. They affect how genes are expressed by modifying RNA or histones.
C. They replace inherited genes with new ones.
D. They only influence genes in the current generatio

Answer 7

B. They affect how genes are expressed by modifying RNA or histones.
Explanation: Environmental factors, including diet or stress, can alter gene expression through epigenetic mechanisms without changing the DNA sequence itself.

Question 8

Which of the following best describes a chromosome abnormality?
A. A mutation in a single gene.
B. An error in the number or structure of chromosomes.
C. A temporary environmental effect on gene expression.
D. A normal variation in genetic inheritance

Answer 8

B. An error in the number or structure of chromosomes.
Explanation: Chromosome abnormalities involve missing, extra, or structurally altered chromosomes, such as in Down syndrome (trisomy 21).

Question 9

Why are most recessive genetic disorders less likely to occur?
A. They require one faulty gene from only one parent.
B. They are influenced by environmental factors rather than inheritance.
C. They require two copies of the faulty gene, one from each parent.
D. They are eliminated by epigenetic changes during developmen

Answer 9

C. They require two copies of the faulty gene, one from each parent.
Explanation: Recessive disorders manifest only if an individual inherits the faulty gene from both parents, reducing their overall likelihood

Question 10

. How do chromosomes contribute to the uniqueness of an individual?
A. Each chromosome is identical in all humans.
B. Chromosomes mix and match during reproduction, creating unique combinations.
C. Chromosomes only carry genes from the mother.
D. Each individual inherits all chromosomes unchanged from their parents

Answer 10

B. Chromosomes mix and match during reproduction, creating unique combinations.
Explanation: Genetic recombination during meiosis ensures each individual has a unique genetic makeup.

Question 11

What is the relationship between genotype and phenotype?
A. Genotype is the physical expression of traits, while phenotype is the genetic code.
B. Genotype determines phenotype but does not always guarantee specific traits.
C. Phenotype influences genotype directly.
D. Phenotype is determined solely by environmental factors, not genetics

Answer 11

B. Genotype determines phenotype but does not always guarantee specific traits.
Explanation: Genotype refers to the genetic makeup, while phenotype is how these genes are expressed, influenced by both genotype and the environment.

Question 12

What is epigenetics?
A. The study of genetic disorders.
B. The process by which environmental factors alter gene expression without changing DNA sequences.
C. The mixing of parental genes during reproduction.
D. The study of physical traits passed through generations

Answer 12

B. The process by which environmental factors alter gene expression without changing DNA sequences.
Explanation: Epigenetics focuses on how factors like diet and stress can modify gene expression through mechanisms such as RNA or histone modifications.

Question 13

How can epigenetics influence future generations?
A. Only DNA mutations are passed down.
B. Environmental changes in one generation can permanently alter gene expression in subsequent generations.
C. Epigenetic changes do not affect inheritance.
D. Epigenetic effects are reset with each new generation

Answer 13

B. Environmental changes in one generation can permanently alter gene expression in subsequent generations.
Explanation: Epigenetic changes, such as methylation, can be inherited and influence gene expression across generations.

Question 14

What distinguishes phenotype from genotype?
A. Phenotype is inherited, while genotype is not.
B. Phenotype is observable traits, while genotype is the genetic code.
C. Genotype is influenced by the environment, while phenotype is not.
D. Genotype determines all traits without environmental input.

Answer 14

B. Phenotype is observable traits, while genotype is the genetic code.
Explanation: Phenotype is how genetic traits are expressed outwardly, influenced by genotype and environmental factors.

Question 15

What type of genetic disorder is most commonly inherited?
A. Dominant disorders requiring only one faulty gene.
B. Recessive disorders requiring faulty genes from both parents.
C. Chromosomal disorders caused by external factors.
D. Disorders caused solely by environmental influences.

Answer 15

B. Recessive disorders requiring faulty ( mutated) genes from both parents.

Explanation: Most inherited genetic disorders are recessive and require both parents to pass on the faulty gene.
cystic fibrosis and sickle cell anemia.
Dominant ones don’t survive

Question 16

What is an example of a chromosomal abnormality?
A. A mutation in a single gene.
B. Down syndrome caused by an extra chromosome 21.
C. A disorder caused by a dominant allele.
D. An inherited recessive genetic disorder.

Answer 16

B. Down syndrome caused by an extra chromosome 21.
Explanation: Chromosomal abnormalities involve structural or numerical changes in chromosomes, such as trisomy 21 in Down syndrome.

Question 17

What role does RNA play in epigenetics?
A. RNA determines the sequence of DNA.
B. RNA directly modifies DNA sequences.
C. RNA influences how genes are expressed, impacting phenotypes.
D. RNA eliminates the influence of environmental factors

Answer 17

C. RNA influences how genes are expressed, impacting phenotypes.
Explanation: RNA and other epigenetic factors helps the body use genetic instructions from DNA to make proteins

Question 18

Why are recessive genetic disorders less common than dominant ones?
A. Recessive genes cannot be inherited.
B. Recessive disorders require two faulty alleles to be expressed.
C. Recessive disorders are more affected by the environment.
D. Recessive disorders only affect males.

Answer 18

B. Recessive disorders require two faulty alleles to be expressed.
Explanation: Both parents must contribute a faulty gene for a recessive disorder to manifest, making them less common.

Question 19

What is an example of how epigenetics interacts with the environment?
A. A child inherits a genetic mutation.
B. Exposure to stress alters gene expression related to stress management.
C. A parent passes on their exact DNA sequence without modifications.
D. Genetic traits are unaffected by diet or environmental factors.

Answer 19

B. Exposure to stress alters gene expression related to stress management.
Explanation: Environmental factors, like stress, can lead to epigenetic changes, influencing how genes are expressed.

Question 20

Which statement about phenotype is correct?
A. Phenotype is determined only by the genotype.
B. Phenotype results solely from environmental factors.
C. Phenotype is influenced by both genetic and environmental factors.
D. Phenotype and genotype are identical concepts.

Answer 20

C. Phenotype is influenced by both genetic and environmental factors.
Explanation: Phenotype reflects the expression of genes and their interaction with environmental influences.

Question 21

What happens when an individual inherits one dominant allele for a genetic trait?
A. The trait will be expressed in the phenotype.
B. The trait will only be expressed if a recessive allele is also inherited.
C. The trait will not appear unless both alleles are dominant.
D. The trait is determined by environmental factors alon

Answer 21

A. The trait will be expressed in the phenotype.
Explanation: Dominant alleles only need one copy to be expressed in the phenotype

Question 22

What causes chromosomal abnormalities?
A. Changes in environmental factors alone.
B. Errors during the formation of sex cells or early embryonic development.
C. External damage to the DNA sequence.
D. Mutations in a single recessive gene.

Answer 22

: B. Errors during the formation of sex cells or early embryonic development.
Explanation: Chromosomal abnormalities often occur due to issues during meiosis or early cell division, leading to missing or extra chromosomes.

Question 23

What is the significance of studying epigenetics in prenatal development?
A. To identify how DNA changes during development.
B. To understand how environmental factors influence gene expression in utero.
C. To predict exact genetic outcomes for an individual.
D. To eliminate inherited genetic disorders.

Answer 23

B. To understand how environmental factors influence gene expression in utero.
Explanation: Epigenetics helps explain how prenatal environmental conditions, like nutrition or stress, can affect gene expression and influence development.

Question 24

What is a mutation in the context of genetics?
A. A temporary change in DNA caused by environmental factors.
B. A permanent alteration in genes or chromosomes that affects an individual.
C. A reversible genetic change that does not influence traits.
D. A minor variation in phenotype unrelated to DNA change

Answer 24

B. A permanent alteration in genes or chromosomes that affects an individual.
Explanation: Mutations are permanent changes in DNA or chromosomes that can influence traits or health.

Question 25

. How are mutations typically acquired? A. They are always inherited from parents. B. They can occur spontaneously or be influenced by heredity. C. They only occur due to environmental exposure. D. They are caused by lifestyle factors alone

Answer 25

B. They can occur spontaneously or be influenced by heredity. Explanation: Mutations may arise randomly during or after conception or be passed down through inheritance.

Question 26

What is the primary genetic cause of Down syndrome? A. A single gene mutation on chromosome 6. B. A mutation in a recessive gene pair. C. An extra copy of the 21st chromosome (trisomy 21). D. A deletion in chromosome 21.

Answer 26

C. An extra copy of the 21st chromosome (trisomy 21). Explanation: Down syndrome occurs when an individual has three copies of chromosome 21

Question 27

What factor is strongly linked to an increased risk of Down syndrome? A. The father’s age at conception. B. Exposure to environmental toxins. C. The mother’s age at conception. D. The diet of the parents.

Answer 27

C. The mother’s age at conception. Explanation: Advanced maternal age significantly increases the likelihood of having a child with Down syndrome.

Question 28

Why is sickle cell anemia more prevalent in certain populations? A. It is a dominant genetic trait. B. It provides protection against malaria in heterozygous carriers. C. It results from spontaneous mutations unrelated to ancestry. D. It spreads through environmental exposur

Answer 28

B. It provides protection against malaria in heterozygous carriers. Explanation: In regions with high rates of malaria, carriers of the sickle cell trait are less likely to die from malaria, making the trait adaptive

Question 29

What is the genetic basis of sickle cell anemia? A. It is caused by a dominant mutation on chromosome 21. B. It is a recessive disorder requiring two faulty alleles. C. It occurs due to environmental influences rather than genetics. D. It results from an extra chromosome in affected individual

Answer 29

: B. It is a recessive disorder requiring two faulty alleles. Explanation: Sickle cell anemia is inherited in a recessive pattern, meaning individuals need two copies of the faulty gene to have the diseas

Question 30

Which of the following is true about carriers of the sickle cell trait? A. They cannot pass the gene to their offspring. B. They are resistant to malaria but do not have the disease. C. They are equally likely to develop sickle cell anemia. D. They are unaffected by the trait in any way.

Answer 30

B. They are resistant to malaria but do not have the disease. Explanation: Carriers (heterozygous individuals) do not develop the disease but benefit from protection against malaria.

Question 31

What percentage of genes do identical twins share? A. 25% B. 50% C. 75% D. 100%

Answer 31

D. 100% Explanation: Identical twins share 100% of their genes because they originate from the same fertilized egg.

Question 32

What is the likelihood of schizophrenia in the children of a parent with the disorder? A. 2% B. 10% C. 13% D. 50%

Answer 32

C. 13% Explanation: Children of a parent with schizophrenia have a 13% chance of developing the disorder, reflecting a genetic predisposition

Question 33

Which chromosome has been linked to a predisposition for schizophrenia? A. Chromosome 21 B. Chromosome 6 C. Chromosome 18 D. Chromosome X

Answer 33

B. Chromosome 6 Explanation: Studies suggest that a gene on chromosome 6 may predispose individuals to schizophrenia.

Question 34

What type of genetic disorder is familial Alzheimer’s disease? A. Dominant B. Recessive C. X-linked D. Chromosomal

Answer 34

A. Dominant Explanation: Familial Alzheimer’s is linked to dominant mutations, meaning one faulty allele is enough to cause the disease.

Question 35

How does maternal age impact the risk of Down syndrome? A. Risk decreases with maternal age. B. Risk is highest before age 20. C. Risk increases significantly after age 35. D. Risk remains constant regardless of ag

Answer 35

C. Risk increases significantly after age 35. Explanation: Advanced maternal age increases the likelihood of chromosomal abnormalities like Down syndrome

Question 36

What percentage of genes do first cousins share? A. 25% B. 12.5% C. 50% D. 6.25%

Answer 36

B. 12.5% Explanation: First cousins share 12.5% of their genes, contributing to their 2% risk of developing schizophrenia if a relative has it.

Question 37

What distinguishes a mutation from a chromosomal abnormality? A. Mutations occur in individual genes, while chromosomal abnormalities involve entire chromosomes. B. Chromosomal abnormalities are always inherited, while mutations are not. C. Mutations and chromosomal abnormalities are identical concepts. D. Mutations affect multiple chromosomes, while chromosomal abnormalities affect single genes

Answer 37

A. Mutations occur in individual genes, while chromosomal abnormalities involve entire chromosomes. Explanation: Mutations are changes in specific genes, while chromosomal abnormalities involve changes to whole chromosomes.

Question 38

Which statement best describes the heritability of schizophrenia? A. It is entirely genetic and unaffected by environmental factors. B. It is influenced by both genetic predisposition and environmental triggers. C. It cannot be inherited from relatives. D. It only occurs in individuals with no family histo

Answer 38

B. It is influenced by both genetic predisposition and environmental triggers. Explanation: Schizophrenia involves genetic risk factors, but environmental influences also play a significant role in its development.

Question 39

When does the environment begin to influence a child’s development? A. After birth B. During the toddler years C. While in utero and even in previous generations D. Only during early childhood

Answer 39

: C. While in utero and even in previous generations Explanation: Environmental factors can influence a child starting from their parents’ experiences and in utero conditions.

Question 40

What is a teratogen? A. A genetic mutation that affects fetal development. B. An environmental agent that can harm a developing fetus. C. A condition that only affects postnatal development. D. A medication designed to enhance prenatal growth

Answer 40

B. An environmental agent that can harm a developing fetus. Explanation: Teratogens include substances like drugs, cigarettes, and toxins that can negatively impact fetal developmen

Question 41

Which of the following is NOT an example of a teratogen? A. Cigarettes B. Over-the-counter medications C. Loud sounds D. Recreational drugs

Answer 41

C. Loud sounds Explanation: Loud sounds can influence prenatal learning, but they are not classified as teratogens.

Question 42

How can a parent’s environment impact their future children before conception? A. It cannot influence children until they are conceived. B. Environmental exposures, such as stress or toxins, can alter genetic expression passed to offspring. C. Only genetic factors influence future children. D. The parent’s environment has no lasting effects on their offsprin

Answer 42

B. Environmental exposures, such as stress or toxins, can alter genetic expression passed to offspring. Explanation: Epigenetics explains how a parent's environment can modify gene expression, affecting future generations.

Question 43

What is a primary function of prenatal learning? A. Preparing for immediate independence after birth. B. Developing recognition of the mother and life outside the womb. C. Fully mastering motor skills before birth. D. Ensuring that no external stimuli affect the fetu

Answer 43

B. Developing recognition of the mother and life outside the womb. Explanation: Prenatal learning prepares infants for breastfeeding, recognizing familiar voices, and other post-birth survival functions

Question 44

At what stage of prenatal development do infants begin responding to sound? A. 10–12 weeks B. 16–18 weeks C. 22–24 weeks D. 30–32 weeks

Answer 44

C. 22–24 weeks Explanation: By 22–24 weeks after conception, fetuses begin responding to sound, using their sense of hearing.

Question 45

What happens when a loud sound is repeatedly presented to a fetus between 24–26 weeks? A. The heart rate increases consistently with each sound. B. The fetus shows no response to sound. C. The initial heart rate response fades with repeated exposure. D. The fetus begins to mimic the sound pattern.

Answer 45

C. The initial heart rate response fades with repeated exposure. Explanation: Fetuses exhibit habituation, where the heart rate response decreases with repeated exposure to the same sound.

Question 46

What preferences do newborns demonstrate regarding sound? A. They prefer random sounds over familiar ones. B. They show no preference for voices or sounds. C. They prefer their mother’s voice and familiar sounds from in utero. D. They are unable to distinguish between voices at birth.

Answer 46

: C. They prefer their mother’s voice and familiar sounds from in utero. Explanation: Newborns can recognize and show a preference for their mother’s voice and sounds they were exposed to before birth.

Question 47

How do prenatal experiences with sound benefit newborns? A. They eliminate the need for postnatal learning. B. They help develop preferences for familiar voices and promote attachment. C. They are unrelated to postnatal sound recognition. D. They prevent the fetus from being startled after birt

Answer 47

B. They help develop preferences for familiar voices and promote attachment. Explanation: Familiar sounds and voices from prenatal experiences promote recognition and bonding after birth.

Question 48

Why is stress during pregnancy a concern for fetal development? A. It directly alters the DNA sequence of the fetus. B. It impacts the mother’s hormones, which can influence the fetus. C. It only affects the fetus after birth. D. It has no measurable impact on development.

Answer 48

B. It impacts the mother’s hormones, which can influence the fetus. Explanation: Maternal stress hormones like cortisol can affect fetal brain development and stress regulation.

Question 49

What sensory experiences do fetuses develop in utero? A. Only hearing B. Hearing, taste, and movement C. Vision and hearing D. No sensory experiences develop before birth.

Answer 49

B. Hearing, taste, and movement Explanation: Fetuses begin to use senses like hearing, taste, and touch in preparation for life outside the womb.

Question 50

How does prenatal exposure to a story influence newborn preferences? A. Newborns show no memory of stories from in utero. B. They recognize and prefer familiar stories heard in utero. C. Stories do not impact newborn preferences or behavior. D. They only remember stories for a few hours after birth.

Answer 50

B. They recognize and prefer familiar stories heard in utero. Explanation: Newborns demonstrate memory and preference for stories they were exposed to before birth.

Question 51

How can teratogens affect fetal development? A. They have no impact if the mother is healthy. B. They may cause physical and cognitive abnormalities depending on timing and exposure level. C. They always result in immediate birth defects. D. They affect only the father’s genetic contribution

Answer 51

B. They may cause physical and cognitive abnormalities depending on timing and exposure level. Explanation: The effects of teratogens depend on factors like the type of teratogen, dose, and timing of exposure during development

Question 52

Why is in utero learning important for breastfeeding? A. It helps the infant physically prepare for feeding. B. It teaches infants how to latch correctly. C. It enables the infant to recognize the mother’s scent and voice for feeding cues. D. It reduces the time infants spend crying after birth

Answer 52

C. It enables the infant to recognize the mother’s scent and voice for feeding cues. Explanation: Prenatal recognition of the mother supports successful breastfeeding by fostering familiarity with her scent and voice.

Question 53

How does the uterine environment prepare infants for postnatal life? A. By isolating them completely from external stimuli. B. By exposing them to sounds, tastes, and movement to practice essential skills. C. By suppressing unnecessary sensory experiences. D. By reducing their reliance on maternal cues.

Answer 53

: B. By exposing them to sounds, tastes, and movement to practice essential skills. Explanation: The prenatal environment helps infants practice and develop sensory and motor systems crucial for survival after birth.

Question 54

What are the three main activities a newborn can perform immediately after birth? A. Walk, cry, and laugh B. Eat, cry, and sleep C. Talk, crawl, and eat D. Blink, talk, and sleep

Answer 54

B. Eat, cry, and sleep

Question 55

What was the historical assumption about newborns? A. They were capable of complex learning immediately after birth. B. They had highly developed motor skills at birth. C. They were helpless and incapable of purposeful actions. D. They were completely independent after birth.

Answer 55

What was the historical assumption about newborns?

Question 56

What primarily controls a newborn's actions? A. Conscious thought B. Voluntary movements C. Reflexes D. Environmental cues

Answer 56

C. Reflexes Explanation: Reflexes are involuntary and unconscious actions that guide many of a newborn’s early behaviors.

Question 57

Which reflex helps maintain a newborn’s oxygen supply? A. Rooting reflex B. Breathing reflex C. Palmar grasping reflex D. Moro reflex

Answer 57

B. Breathing reflex Explanation: Reflexes like breathing, hiccupping, and sneezing ensure a newborn maintains oxygen level

Question 58

What is the purpose of the thrashing reflex in newborns? A. To help regulate body temperature. B. To maintain oxygen supply by clearing airways. C. To seek food. D. To display brain developmen

Answer 58

B. To maintain oxygen supply by clearing airways. Explanation: Thrashing helps a newborn remove obstructions from their face to ensure proper breathing.

Question 59

Which reflex is associated with regulating a newborn’s body temperature? A. Sucking reflex B. Shivering reflex C. Babinski reflex D. Palmar grasping refle

Answer 59

B. Shivering reflex Explanation: Shivering is an involuntary response to help regulate and maintain body temperature.

Question 60

What is the rooting reflex? A. The reflex to grasp objects placed in the palm. B. The reflex to turn the head and open the mouth when the cheek is touched. C. The reflex to cry when uncomfortable. D. The reflex to push away blankets when overheated.

Answer 60

B. The reflex to turn the head and open the mouth when the cheek is touched. Explanation: The rooting reflex helps newborns find a food source, such as the mother’s breast.

Question 61

What does the sucking reflex enable a newborn to do? A. Maintain oxygen levels. B. Feed effectively by drawing milk. C. Regulate body temperature. D. Respond to falling sensations.

Answer 61

: B. Feed effectively by drawing milk. Explanation: The sucking reflex is essential for feeding and helps newborns consume milk from the breast or bottle.

Question 62

Which reflex is associated with an infant’s toes fanning out when the sole of the foot is stroked? A. Moro reflex B. Babinski reflex C. Swimming reflex D. Palmar grasping reflex

Answer 62

B. Babinski reflex Explanation: The Babinski reflex causes an infant's toes to fan out when the sole of the foot is stroked, and it indicates healthy neurological function

Question 63

What is the Moro reflex? A. A reflex to turn toward a touch on the cheek. B. A reflex to grasp objects placed in the palm. C. A reflex involving the arms flinging out when the infant feels a loss of support. D. A reflex to push away blankets when overheated.

Answer 63

C. A reflex involving the arms flinging out when the infant feels a loss of support. Explanation: The Moro reflex occurs when a baby feels like they are falling, causing their arms and legs to flail outward.

Question 64

What is the purpose of the swimming reflex? A. To allow newborns to move effectively on land. B. To show signs of voluntary muscle development. C. To help infants move arms and legs in a swimming motion when placed on their stomach. D. To regulate body temperature during water exposure

Answer 64

C. To help infants move arms and legs in a swimming motion when placed on their stomach. Explanation: The swimming reflex mimics swimming motions and may help in survival situations involving water

Question 65

Which reflex helps demonstrate early neurological health when an object is placed in a baby’s hand? A. Babinski reflex B. Palmar grasping reflex C. Rooting reflex D. Moro reflex

Answer 65

B. Palmar grasping reflex Explanation: The palmar grasping reflex causes a newborn to grip an object placed in their palm, indicating normal brain and nervous system development.

Question 66

Why do newborns have the ability to cry immediately after birth? A. To regulate body temperature. B. To establish communication and signal needs. C. To practice voluntary sound production. D. To show discomfort in noisy environments.

Answer 66

B. To establish communication and signal needs. Explanation: Crying is an instinctive way for newborns to signal hunger, discomfort, or other needs.

Question 67

What can the presence or absence of reflexes in newborns indicate? A. The likelihood of future learning difficulties. B. The immediate need for medical intervention. C. The overall health and function of the brain and nervous system. D. Whether the baby will meet motor milestones earlier than average.

Answer 67

C. The overall health and function of the brain and nervous system. Explanation: Reflexes are used to assess healthy brain and nervous system function in newborns.

Question 68

Which reflex is most closely related to feeding behaviors in newborns? A. Babinski reflex B. Rooting reflex C. Palmar grasping reflex D. Moro refle

Answer 68

B. Rooting reflex Explanation: The rooting reflex helps the infant locate a food source by turning their head and opening their mouth when their cheek is touche

Question 69

By what factor does an infant's weight increase by their second birthday? A. 2x B. 3x C. 4x D. 5x

Answer 69

C. 4x Explanation: By two years of age, an infant’s weight typically quadruples (4x) from their birth weight.

Question 70

If a person weighed 150 pounds and continued their early growth rate, how much would they weigh after two years? A. 300 lbs B. 450 lbs C. 600 lbs D. 1,200 lbs

Answer 70

C. 600 lbs

Question 71

By the age of two, how much has an infant's height increased compared to their birth length? A. 1.5x B. 1.7x C. 2x D. 2.5x

Answer 71

B. 1.7x Explanation: At two years old, an infant’s height is typically 1.7 times their birth length

Question 72

If a newborn is 20 inches long, how tall would they likely be by age two? A. 34 inches B. 40 inches C. 44 inches D. 50 inches

Answer 72

A. 34 inches Explanation: Multiply the newborn’s length by 1.7 to estimate their height at two years (20 x 1.7 = 34 inches).

Question 73

What is the significance of percentiles in growth charts? A. They measure genetic potential. B. They rank an infant’s growth compared to a specific population. C. They indicate how tall an infant will be in adulthood. D. They only track weight, not height or other factors

Answer 73

B. They rank an infant’s growth compared to a specific population. Explanation: Percentiles show where a child falls in comparison to others in their age group for growth indicators like height and weight

Answer 74

C. 30% of the population is smaller, and 70% is larger. Explanation: Percentiles indicate relative position; a child in the 30th percentile is smaller than 70% of their peers

Question 75

Why might dips in a child’s percentile chart be concerning? A. They indicate a genetic disorder. B. They could suggest underlying health or growth issues. C. They always mean the child is malnourished. D. They show the child is growing faster than expected

Answer 75

B. They could suggest underlying health or growth issues. Explanation: Significant drops in percentiles might indicate problems with nutrition, growth, or development.

Question 76

How much do newborns typically sleep per day? A. 8–10 hours B. 12–14 hours C. 15–17 hours D. 20–22 hours

Answer 76

C. 15–17 hours Explanation: Newborns sleep around 15–17 hours daily, often in 1–3-hour segments.

Question 77

What is a characteristic of a newborn’s sleep pattern? A. Long uninterrupted periods of deep sleep B. Active sleep with frequent awakenings C. No REM sleep D. Irregular sleep cycles that do not affect brain development

Answer 77

B. Active sleep with frequent awakenings Explanation: Newborns have active sleep with frequent arousals, which is biologically normal and essential for their development.

Question 78

What is active sleep in newborns? A. A state of shallow sleep that allows easier awakening. B. A deep sleep phase with minimal movement. C. A period with no dreams or brain activity. D. A phase where newborns are physically active while asleep.

Answer 78

A. A state of shallow sleep that allows easier awakening. Explanation: Active sleep is a lighter sleep stage where newborns can be easily awakened and return to sleep quickly.

Question 79

What proportion of a newborn’s sleep is REM sleep? A. Very low B. Moderate C. High D. None

Answer 79

C. High Explanation: Newborns spend a large proportion of their sleep in REM, which is vital for brain development and memory consolidatio

Question 80

Why is REM sleep important for newborns? A. It helps maintain body temperature. B. It consolidates information and supports learning. C. It allows for muscle growth and motor skill practice. D. It is the only type of sleep newborns experienc

Answer 80

B. It consolidates information and supports learning. Explanation: REM sleep is critical for processing and retaining information acquired during the day.

Question 81

How do biological and social factors affect newborn sleep patterns? A. Social factors have no impact on newborn sleep. B. Biological needs exclusively determine sleep patterns. C. Both biological rhythms and caregiving practices influence sleep. D. Social factors disrupt natural biological sleep patterns.

Answer 81

C. Both biological rhythms and caregiving practices influence sleep. Explanation: Newborn sleep patterns are shaped by biological needs and caregiving routines.

Question 82

What might cause a newborn to experience irregular sleep patterns? A. Lack of REM sleep B. Immature biological rhythms and external disruptions C. Fully developed circadian rhythms D. Inability to distinguish between day and night sounds

Answer 82

B. Immature biological rhythms and external disruptions Explanation: Newborns’ circadian rhythms are still developing, and external factors like feeding schedules can influence their sleep.

Question 83

How do frequent awakenings during active sleep benefit newborns? A. They allow newborns to consume more calories. B. They ensure newborns can respond to environmental needs. C. They disrupt REM sleep for better growth. D. They signal developmental issues.

Answer 83

B. They ensure newborns can respond to environmental needs. Explanation: Frequent awakenings during active sleep allow newborns to respond to hunger, discomfort, or environmental changes

Question 84

By what age does the brain reach 50% of its adult weight? A. 6 months B. 1 year C. 2 years D. 5 years

Answer 84

C. 2 years Explanation: By the age of 2, the brain has reached 50% of its adult weight, reflecting rapid early growth.

Question 85

What percentage of its adult weight does a child’s head achieve by age two? A. 50% B. 60% C. 75% D. 90%

Answer 85

C. 75% Explanation: At age two, a child's head achieves 75% of its adult size, highlighting the importance of early brain growth.

Question 86

What is "head-sparing," and why is it important? A. A reflex that protects the head during falls. B. A mechanism protecting the brain during malnutrition. C. A genetic trait that ensures proportional head growth. D. A physical feature limiting brain development under stres

Answer 86

B. A mechanism protecting the brain during malnutrition. Explanation: Head-sparing is a biological process prioritizing brain growth and function during times of severe malnutrition or stress.

Question 87

Why is measuring head circumference important in infancy? A. It helps identify genetic traits. B. It reflects prenatal and postnatal brain growth critical for cognition. C. It determines future physical development. D. It predicts social development milestones.

Answer 87

B. It reflects prenatal and postnatal brain growth critical for cognition. Explanation: Head circumference is a key indicator of healthy brain growth, which is crucial for later cognitive abilities.

Question 88

What is the role of dendrites in neurons? A. They carry signals away from the neuron. B. They store neurotransmitters. C. They receive and pass electrochemical signals to the neuron. D. They insulate axons to speed up signal transmission.

Answer 88

C. They receive and pass electrochemical signals to the neuron. Explanation: Dendrites are specialized structures that receive information from other neurons and transmit it to the cell body.

Question 89

What are neurotransmitters? A. Structures that insulate axons for faster transmission. B. Brain chemicals that carry information between neurons. C. Hormones that control brain growth. D. Signals that block neural communication.

Answer 89

B. Brain chemicals that carry information between neurons. Explanation: Neurotransmitters are chemical messengers that facilitate communication between neurons across synapses.

Question 90

What is myelination? A. The process of forming new neurons. B. The insulation of axons to speed up neural communication. C. The destruction of unnecessary neural connections. D. The growth of dendrites to receive signal

Answer 90

B. The insulation of axons to speed up neural communication. Explanation: Myelination involves coating axons with a fatty substance called myelin, which enhances the speed and efficiency of signal transmission

Question 91

By age two, what is true about synaptic growth in the brain? A. Synaptic density is lower than at birth. B. Synaptic density becomes extremely high and bushy. C. Synaptic connections are finalized. D. Synaptic growth slows due to limited experience

Answer 91

B. Synaptic density becomes extremely high and bushy. Explanation: At age two, the brain undergoes significant synaptic growth, resulting in a dense and bushy neural network.

Question 92

What is the purpose of synaptic pruning? A. To eliminate unnecessary synapses and enhance efficiency. B. To create new synapses for future learning. C. To slow down information processing. D. To protect the brain from overuse.

Answer 92

A. To eliminate unnecessary synapses and enhance efficiency. Explanation: Synaptic pruning removes unused neural connections, making the brain more efficient and adaptable to new experiences.

Question 93

Which part of the brain experiences the highest synaptic density by age two? A. Occipital lobe B. Parietal lobe C. Temporal lobe D. Frontal lobe

Answer 93

D. Frontal lobe Explanation: The frontal lobe, responsible for advanced cognitive functions, has the highest synaptic density by age two

Question 94

What is the "use it or lose it" principle in brain development? A. The idea that unused neural connections are pruned to enhance efficiency. B. The concept that neurons deteriorate with age. C. The belief that early experiences permanently determine brain function. D. The process of losing brain cells after birth

Answer 94

A. The idea that unused neural connections are pruned to enhance efficiency. Explanation: The "use it or lose it" principle ensures that only frequently used connections are retained, allowing for better adaptability.

Question 95

Why is synaptic pruning beneficial for the brain? A. It ensures the brain retains all early experiences. B. It allows the brain to focus resources on important and frequently used connections. C. It stops the brain from creating new neural pathways. D. It reduces brain activity to conserve energy

Answer 95

B. It allows the brain to focus resources on important and frequently used connections. Explanation: Synaptic pruning optimizes the brain’s efficiency by removing redundant or unused connections.

Question 96

What speeds up the processing of information through the brain and body during infancy? A. Myelination B. Neurotransmitters C. Synaptic pruning D. Dendritic growth

Answer 96

A. Myelination Explanation: Myelination insulates axons, enabling faster and more efficient communication between neurons.

Question 97

What is the relationship between prenatal malnutrition and brain growth? A. Malnutrition has no effect on brain development. B. Head-sparing prioritizes brain growth over other body parts during malnutrition. C. Brain growth stops entirely during malnutrition. D. Malnutrition enhances synaptic pruning

Answer 97

B. Head-sparing prioritizes brain growth over other body parts during malnutrition. Explanation: Head-sparing ensures that the brain continues to grow and develop even when resources are limited.

Question 98

How do researchers detect infant perception? A. By directly asking infants to describe what they see. B. By observing involuntary behaviors like gaze, sucking, or physical reactions. C. By testing infants’ verbal responses. D. By using genetic testing

Answer 98

B. By observing involuntary behaviors like gaze, sucking, or physical reactions. Explanation: Infants’ perception is studied through their reflexive behaviors, such as looking time, sucking rate, and motor responses, as they cannot communicate verbally.