Lab Test 3 Genetics/embryology

Front 1

The normal human cell contains ____ pieces of DNA (chromosomes) in the nucleus.

Back 1

46

Front 2

a human has_____ pairs of chromosomes.

Back 2

23

Front 3

Each member of a pair is roughly the same size and codes for the same type of traits (hair color, eye color, lactase production, etc) at the some place on the chromosome.
True or False

Back 3

True

Front 4

If each pair is roughly the same size and codes for the same type of traits (like hair, eyes, etc.) then this is called.

Back 4

Homolgous pairs

Front 5

Genes that code for the same type of trait are called ___________.

Back 5

alleles

Front 6

Alleles differ slightly in the nucleotide sequence, but those differences have big results.

True or False

Back 6

True

Front 7

During _________ each sperm and egg cell only receive 1 member of each homologous pair.

Back 7

meiosis

Front 8

During ____________ the normal number is reproduced giving 23 pairs, because the sperm and egg will only give one of each homologous pair.

Back 8

fertilization

Front 9

Cells with only 1 of each pair are called
a. diploid
b.haploid

Back 9

haploid

Front 10

Cells with both members of each pair are called
a. diploid
b. haploid

Back 10

diploid

Front 11

During meiosis the members of ______________-may actually exchange some parts of the chromosomes. This _____________ provides even more diversity to the possible gene combinations.

Back 11

homologous pairs
crossing over

Front 12

The mix of maternal and paternal chromosomes at __________ is another way that diversity is provided since each parent contributes only one __________ to the pair.

Back 12

fertilization
allele

Front 13

When the maternal and paternal alleles for a trait interact many different variations may be seen.
The exact genetic combination for a trait is called its ___________.

Back 13

genotype

Front 14

When the maternal and paternal alleles for a trait interact many different variations may be seen. The resulting physical trait from that combination is the _____________.

Back 14

phenotype

Front 15

Complete dominance occurs when one allele _____________completely masks the expression of another allele ________________.

Back 15

(dominant)
(recessive)

Front 16

In _____________________________the dominant trait is seen whenever the dominant allele is present. But, the recessive trait is only seen in the absence of the dominant allele.

Back 16

complete dominance

Front 17

______________________ is when there is a mixing of the two expressions when both alleles are present.

Back 17

Incomplete dominance

Front 18

In pea plants a gene pair controls height. ‘T’ is the allele for tall and is dominant to ‘t’, the allele for dwarf plant height. A plant with two dominant alleles (TT) is called _______________ and shows the ______________ - tall.

Back 18

homozygous dominant
dominant phenotype

Front 19

In pea plants a gene pair controls height. ‘T’ is the allele for tall and is dominant to ‘t’, the allele for dwarf plant height. One with two recessives (tt) is ________________ and shows the _______________ – dwarf.

Back 19

homozygous recessive
recessive phenotype

Front 20

In pea plants a gene pair controls height. ‘T’ is the allele for tall and is dominant to ‘t’, the allele for dwarf plant height. A mix of the two (Tt) is called ____________and still is tall because these genes show _____________________.

Back 20

heterozygous
complete dominance

Front 21

During egg and sperm production each ____________ (egg or sperm cell) receives only one of each pair of genes.

Back 21

gamete

Front 22

In pea plants a gene pair controls height. ‘T’ is the allele for tall and is dominant to ‘t’, the allele for dwarf plant height. So a plant that is heterozygous can make gametes that have either T or t alleles. The probability of a gamete getting either is ______%.

Back 22

50%

Front 23

A homozygous plant can only make one type of gamete for that trait since it only has one type of allele.
True or False

Back 23

True

Front 24

A cross between parents where we only look at one trait is a monohybrid cross and is the simplest of all crosses.
a. Sex-linked
b. monohybrid
c. Incomplete Dominance
d. Multiple alleles

Back 24

b. monohybrid

Front 25

A handy tool used to see the possible combinations of a particular cross is called a ______________.

Back 25

Punnett’s Square.

Front 26

A ______________ trait is one that is found on the part of the X chromosome that does not have a corresponding place (locus) on the Y.
a. Sex-linked
b. monohybrid
c. Incomplete Dominance
d. Multiple alleles

Back 26

a. Sex-linked

Front 27

A sex-linked trait is one that is found on the part of the X chromosome that does not have a corresponding place (locus) on the Y. Therefore, in males a recessive allele on his X chromosome in that locus is always expressed because there is no allele on the Y to match it.
True or False

Back 27

True

Front 28

A __________ cross looks a two traits on separate chromosome pairs. The Punnett’s square is bigger, but the principles are the same.
a. Sex-linked
b. monohybrid
c. Incomplete Dominance
d. dihybrid

Back 28

d. dihybrid

Front 29

What is the study of development from conception until birth

Back 29

Embryology

Front 30

After ___________ the egg cell enters the uterine tube and is slowly transported toward the __________ by the action of cilia on the surface of the epithelium lining the tube.

Back 30

ovulation
uterus

Front 31

The egg is only viable for _________ hours after ovulation. If not fertilized in that time it will degenerate.

Back 31

12 to 24

Front 32

The sperm is able to fertilize for only _________ hours.

Back 32

24 to 48

Front 33

Sperm cells undergo a process called _______________ as they swim toward the egg cell. This prepares them to be able to fertilize the egg.

Back 33

capacitation

Front 34

Successful fertilization usually occurs at about _________of the way down the tube.

Back 34

1/3

Front 35

When a sperm cell finally penetrates the egg and fertilizes it, a series of reactions occur that prevent other sperm from also contributing their DNA.

True or False

Back 35

True

Front 36

The DNA of the sperm and egg is each only ________ of the normal DNA.

Back 36

half

Front 37

When they combine it reproduces the normal amount for the species of ________pairs of chromosomes.

Back 37

23

Front 38

The fertilized egg is called a ____________.

Back 38

zygote

Front 39

The zygote begins to divide by ____________ in about 36 hours. This early time of division is called ___________.
a. meiosis, 24, cleavage
b. mitosis, 36, pre-cleavage
c. mitosis, 36, cleavage
d. meiosis, 24, pre-cleavage

Back 39

c. mitosis, 36, cleavage

Front 40

During fertilization, the egg is steadily proceeding toward the uterus.
True or False

Back 40

True

Front 41

At 3 days the zygote has become a bll of cells called _________.
a. implantation
b. blastocystl
c. morula
d. gastrula

Back 41

c. morula

Front 42

After 3 days, a fluid chamber begins to develop and the entire structure is a __________.
a. implantation
b. blastocystl
c. morula
d. gastrula

Back 42

b. blastocyst

Front 43

Finally the uterus is reached just at the peak time for proper _______________ in the endometrium – 6 days.
a. implantation
b. blastocystl
c. morula
d. gastrula

Back 43

a. implantation

Front 44

After implantation the outer cells of the blastocyst and the cells of the endometrium begin to form the ________.

Back 44

placenta

Front 45

what will be the growing child’s only source of oxygen and nutrients?

Back 45

placenta

Front 46

There is direct mixing of fetal and maternal blood but the two flow next to one another and allow for gas and nutrient/waste exchange.
True or False

Back 46

false there is not a direct mixing of fetal and maternal blood

Front 47

The blastocyst develops further to become a _________.

Back 47

d. gastrula

Front 48

In the gastrula emerge the three types of primary germ layers. Name them.

Back 48

Ectoderm
Endoderm
Mesoderm

Front 49

Describe the three primary germ layers.

Back 49

Ectoderm will go on to form epidermis and nervous system.

Endoderm becomes the epithelial lining of the digestive, respiratory, and urogenital systems.

Mesoderm forms everything else.

Front 50

Which primary germ layer goes on to form epidermis and nervous system?

Back 50

Ectoderm

Front 51

Which primary germ layer becomes the epithelial lining of the digestive, respiratory, and urogenital systems?

Back 51

Endoderm

Front 52

Which primary germ layer forms everything else?

Back 52

Mesoderm

Front 53

Week 1 – 8 of development is the embryonic period. During this time the conceptus is called an ___________.

Back 53

embryo.

Front 54

At week 9 to 40 weeks the conceptus is now called a ________.

Back 54

fetus

Front 55

What is the allele that hides or masks its alternative allele?

Back 55

dominant

Front 56

What is the allele that is the allele being masked or hidden by the dominant allele?

Back 56

recessive

Front 57

What is the allele that determines a specific characteristic?

Back 57

genotype

Front 58

What is the appearance of an individual with regard to a particular trait?

Back 58

phenotype

Front 59

What is it called if an individual has two identical alleles for a particular trait?

Back 59

homozygous

Front 60

What is it called when an individual has two different alleles for a particular trait?

Back 60

heterozygous

Front 61

What are genes that are located only on the X chromosome?

Back 61

sex-linked genes

Front 62

What is the matings between individuals that differ with respect to one pair of alleles?

Back 62

monohybrid crosses

Front 63

What is it when a group of alleles containing three or more alternative forms?

Back 63

multiple alleles

Front 64

What is the condition in which the heterozygote exhibits a phenotype that is intermediate between the phenotypes of the two homozygotes?

Back 64

incomplete dominance