principle of inheritance

Question 1

Mutation is —– (def)

Answer 1

phenomenon which results in alternation of DNA seqs and consequently results changes in the genotype and phenotype of an organism

Question 2

In addition to —-, mutation is another
phenomenon that leads to —- in DNA.

Answer 2

recombination
variation

Question 3

One —- runs continuously from one end to the other in each chromatid, in a —- form.

Answer 3

DNA helix
highly supercoiled

Question 4

Therefore loss (—-) or gain (—–) of a —-, result in alteration in —–.

Answer 4

deletions
insertion /duplication
segment of dna
chromosomes

Question 5

Since genes are known to be located on chromosomes, alteration in chromosomes results in —- or —-

Answer 5

abnormalities or aberrations.

Question 6

Chromosomal aberrations are commonly observed in —-

Answer 6

cancer cells

Question 7

In addition to the above, mutation also arise due to change in a single — of DNA. This is known as —-.

Answer 7

base pair
point mutation

Question 8

A classical example of — is sickle cell anemia.

Answer 8

point mutation

Question 9

Deletions and insertions of base pairs of DNA, causes —- mutations

Answer 9

frame-shift mutations

Question 10

There are many — and —– factors that
induce mutations. These are referred to as —.

Answer 10

chemical and physical
mutagens

Question 11

—-radiations can
cause mutations in organisms – it is a –.

Answer 11

UV
mutagen.

Question 12

The idea that disorders are — has been prevailing in the human society since —. This was based on the heritability of certain—- in families.

Answer 12

inherited
long
characteristic features

Question 13

After the rediscovery of Mendel’s work the practice of analysing —- in human beings began.

Answer 13

inheritance pattern of traits

Question 14

Since it is evident that —- that can be performed in
pea plant or some other organisms, are not possible in case of human
beings, study of the —- about inheritance of a —
provides an alternative.

Answer 14

control crosses
family history
particular trait

Question 15

Such an analysis of traits in a several of generations of a family is called the —-

Answer 15

pedigree analysis

Question 16

In the pedigree analysis the inheritance of a particular trait is represented in the — over generations.

Answer 16

family
tree

Question 17

In human genetics, — provides a strong tool, which is utilised to trace the inheritance of a —-, — or —–

Answer 17

pedigree study
specific trait, abnormality or disease.

Question 18

Each and every feature in any organism is controlled by —- located on the DNA present in the chromosome.

Answer 18

one or the other gene

Question 19

DNA is the carrier of —.

Answer 19

genetic information

Question 20

DNA is hence transmitted from one generation to the other without any —. However, changes or alteration do take place occasionally. Such an alteration or change in the —- is referred to as
—.

Answer 20

change or alteration
genetic material
mutation

Question 21

A number of disorders in human beings have been found to be associated with the inheritance of —-

Answer 21

changed or altered genes or chromosomes.

Question 22

Broadly, genetic disorders may be grouped into two
categories – —- and —-

Answer 22

Mendelian disorders and Chromosomal disorders.

Question 23

Mendelian disorders are mainly determined by alteration or mutation in the —-.

Answer 23

SINGLE GENE

Question 24

—- disorders are transmitted to the
offspring on the same lines as we have studied in the principle of inheritance.

Answer 24

Mendellian

Question 25

The — of such Mendelian disorders can be traced in a family by the pedigree analysis.

Answer 25

pattern of inheritance

Question 26

Most common and prevalent Mendelian disorders are —- (6) etc.

Answer 26

Haemophilia, Cystic fibrosis, Sickle-cell anaemia,
Colour blindness, Phenylketonuria, Thalassemia,

Question 27

It is important to mention here that such Mendelian
disorders may be — or —.

Answer 27

dominant or recessive

Question 28

By pedigree analysis one can — whether the trait in question is dominant or recessive. Similarly,
the trait may also be —-
as in case of haemophilia.

Answer 28

easily understand
linked to the sex chromosome

Question 29

It is evident that this —
shows transmission from carrier female to male progeny.

Answer 29

X-linked recessive trait

Question 30

Haemophilia : This sex linked — disease, which shows its transmission from — female to – of the male progeny has been widely studied. In this disease, a single protein that is a part
of the cascade of proteins involved in the clotting of blood is affected.
Due to this, in an affected individual a simple cut will result in non-stop
bleeding. The heterozygous female (carrier) for haemophilia may transmit
the disease to sons. The possibility of a female becoming a haemophilic
is extremely rare because mother of such a female has to be at least
carrier and the father should be haemophilic (unviable in the later stage
of life). The family pedigree of Queen Victoria shows a number of
haemophilic descendents as she was a carrier of the disease

Answer 30

recessive
unaffected carrier
some

Question 31

In heamophilia, a — that is a part of the — of proteins involved in the clotting of blood is affected.

Answer 31

single protein
cascade

Question 32

Due to this, in an affected individual a — will result in non-stop bleeding.

Answer 32

simple cut

Question 33

The heterozygous female (—-) for haemophilia may transmit the disease to —.

Answer 33

carrier
sons

Question 34

The possibility of a female becoming a haemophilic
is —- because mother of such a female has to be — and the father should be — (— in the later stage
of life).

Answer 34

extremely rare
at least carrier
haemophilic-unviable

Question 35

The family pedigree of — shows a number of
— descendents as she was a carrier of the disease

Answer 35

Queen Victoria
haemophilic

Question 36

Sickle-cell anaemia : This is an —- trait that can
be transmitted from parents to the offspring when both the partners are — for the gene (or –).

Answer 36

autosome linked recessive
carrier- heterozygous

Question 37

Sickle cell anemia is controlled by a — allele, HbA and HbS

Answer 37

single pair of

Question 38

Out of the three possible genotypes in SCA only
—- show the diseased phenotype.

Answer 38

homozygous individuals for HbS (HbSHbS)

Question 39

Heterozygous (HbAHbS) individuals appear — but they are carrier of the disease as there is 50 per cent probability of transmission of the —gene to the progeny, thus exhibiting sickle-cell trait

Answer 39

apparently unaffected
mutant

Question 40

SCA is caused by the substitution of — by — ) at the — position of the — chain of the — molecule.

Answer 40

Glutamic acid (Glu) by valine (Val)
sixth
beta globin
haemoglobin

Question 41

The substitution of amino acid in the globin protein results due to the — substitution at the sixth — of the beta globin gene from —- to —-

Answer 41

single base
codon
GAG to GUG.

Question 42

The mutant haemoglobin molecule undergoes
polymerisation under —- causing the change in the shape of the RBC from —- to —- structure

Answer 42

low oxygen tension
biconcave disc to elongated sickle like

Question 43

Phenylketonuria :
This —- is also inherited as the autosomal — trait.

Answer 43

inborn error of metabolism
recessive

Question 44

The PKU affected individual lacks — that converts the amino acid —- to —-

Answer 44

an enzyme
phenylalanine into tyrosine

Question 45

As a result of this, in PKU phenylalanine is accumulated and converted into — and —-

Answer 45

phenylpyruvic acid
and other derivatives.

Question 46

Accumulation of phenyl pyruvic acids and derivatives in brain results in —-.
These are also excreted through — because of its —-

Answer 46

mental retardation
urine
poor absorption by kidney.

Question 47

The chromosomal disorders on the other hand are caused due to —-, — or —- of one or more chromosomes.

Answer 47

absence or excess or abnormal arrangement

Question 48

Failure of —- during cell division cycle results
in the gain or loss of a chromosome(s), called —.

Answer 48

segregation of chromatids
aneuploidy

Question 49

— results in the gain of extra copy of chromosome 21.

Answer 49

Down’s syndrome

Question 50

Similarly, — results due to loss of an X chromosome in human —.

Answer 50

Turner’s syndrome
females

Question 51

Failure of — after — stage of cell division results in an increase in a whole set of chromosomes in an organism and, this phenomenon is known as polyploidy.

Answer 51

cytokinesis
telophase

Question 52

polyploidy is often seen in —.

Answer 52

plants

Question 53

The total number of chromosomes in a
normal human cell is 46 (23 pairs). Out of these
— are autosomes and one pair of chromosomes are — chromosome.

Answer 53

22 pairs
sex

Question 54

Sometimes, —, either an additional copy of a chromosome may be included in an individual or an individual may lack — of chromosomes. These situations are
known as — or – of a
chromosome, respectively.

Answer 54

though rarely
one of any one pair
trisomy or monosomy

Question 55

Such a situation of mono/trisomy
leads to — consequences in the individual. Down’s syndrome, Turner’s
syndrome, — syndrome are common examples of chromosomal disorders.

Answer 55

very serious
Klinefelter’s

Question 56

Down’s Syndrome :
The cause of this genetic
disorder is the presence of an additional copy
of the chromosome number 21 (—).

Answer 56

trisomy of 21

Question 57

Downs syndrome was first described by —

Answer 57

Langdon Down (1866).

Question 58

The down syndrome affected individual is — with —, and —-
Palm is — with —.

Answer 58

short statured
small round head
furrowed tongue
partially open mouth

broad
characteristic palm crease

Question 59

In down syndrome- —, — and —- development is retarded

Answer 59

Physical, psychomotor and mental

Question 60

Klinefelter’s Syndrome : This genetic disorder is also caused due to the presence of an additional copy of — resulting into
a karyotype of —

Answer 60

X-chromosome
47, XXY.

Question 61

Inds with Klinefilter has
overall — development , however, the —development (development of —) is also expressed
Such individuals are —.

Answer 61

masculine
feminine
breast,
i.e., Gynaecomastia
sterile

Question 62

Turner’s Syndrome :
Such a disorder is
caused due to the — of one of the X chromosomes, i.e., —,

Answer 62

absence
45 with X0

Question 63

Females with turners
are sterile as — besides
other features including —

Answer 63

ovaries are rudimentary
lack of other secondary
sexual characters

Question 65

The mechanism of — has
always been a puzzle before the geneticists.
The initial clue about the genetic/
chromosomal mechanism of sex
determination can be traced back to some
of the experiments carried out in insects. In
fact, the cytological observations made in a
number of insects led to the development of
the concept of genetic/chromosomal basis
of sex-determination

Answer 65

sex determination

Question 66

The initial clue about the — mechanism of sex
determination can be traced back to some
of the experiments carried out in — . In
fact, the cytological observations made in a
number of insects led to the development of
the concept of genetic/chromosomal basis
of sex-determination

Answer 66

genetic/ chromosomal
insects

Question 67

In fact, the — made in a
number of insects led to the development of
the concept of
genetic/chromosomal basis of sex-determination

Answer 67

cytological observations

Question 68

—- could trace a specific —structure all through
spermatogenesis in a few insects, and it was also observed by him that —- of the sperm received this structure after
spermatogenesis, whereas the other — sperm did not receive it

Answer 68

Henking (1891)
nuclear
50 per cent, 50 per
cent

Question 69

Henking gave a name to this structure as the — but he could not explain its —.

Answer 69

X body
significance

Question 70

Further investigations by other scientists led to the
conclusion that the ‘X body’ of — was in fact a — and that is why it was given the name X-chromosome.

Answer 70

Henking
chromosome

Question 71

It was also observed that in a —- the mechanism of sex determination is of the XO type, i.e., all — bear an additional
X-chromosome besides the other chromosomes (—)

Answer 71

large number of insects
eggs
autosomes

Question 72

On the other hand, some of the — bear the
X-chromosome whereas some do not in insects.
Eggs fertilised by sperm having an X-chromosome become — and, those fertilised by sperms that do not have an X-chromosome become —.

Answer 72

sperms
females
males

Question 73

Due to the involvement of the X-chromosome in the
—, it was designated to
be the sex chromosome, and the rest of the chromosomes were named as autosomes

Answer 73

determination of sex

Question 74

Grasshopper is an example of XO type of sex
determination in which the males have — whereas females have a —-

Answer 74

only one X-chromosome besides the autosomes,
pair of X-chromosomes.

Question 75

These observations led to the — of a number of species to understand the mechanism of sex determination.

Answer 75

investigation

Question 76

In a number of other
— and —- XY type of sex determination is seen where both male and female have — of chromosomes.

Answer 76

insects and mammals including man,
same number

Question 77

In mammals and other insects, Among the males an X-chromosome is present but its counter part is– and called the Y-chromosome.
Females, however, have
a pair of X-chromosomes. Both males and females bear same number of
— . Hence, the males have autosomes plus XY, while female have autosomes plus XX.

Answer 77

distinctly smaller
autosomes

Question 78

In — and — the males have one X and one Y chromosome, whereas females have a pair of Xchromosomes besides autosomes

Answer 78

human beings and in Drosophila

Question 79

In both XO type and XY type, — produce two different types of gametes, (a) either with or without X-chromosome or (b) some gametes with X-chromosome and some with Y-chromosome.
Such types of sex determination mechanism is designated to be the example of —-.

Answer 79

males
male heterogamety

Question 80

In some other organisms, e.g., — , a different mechanism of sex determination is seen where total number of chromosome is same in both males and females. But two —- in terms of the sex chromosomes, are produced by females, i.e., —.

Answer 80

birds
different types of gametes
female heterogamety

Question 81

In order to have a distinction with the mechanism of sex determination described earlier, the two different sex chromosomes
of a female bird has been designated to be the — chromosomes.

Answer 81

Z and W

Question 82

In birds, the females have one Z and one W chromosome,
whereas males have a —besides the autosomes.

Answer 82

pair of Z-chromosomes

Question 83

sex determining mechanism in case of humans is — type.

Answer 83

XY type

Question 84

The presence of an X and Y chromosome are — of the male characteristic in humans.

Answer 84

determinant

Question 85

In humans, There is an — of fertilisation of the ovum with the sperm carrying either X or Y chromosome. Thus, it is evident that it is the — of — that determines the sex of the child.
It is also evident that in — there is always 50 per cent probability of either a male or a female child.

Answer 85

equal probability
genetic makeup of the
sperm
each pregnancy

Question 86

It is unfortunate that in our society women are blamed for giving birth to female children and have been —- and —- because of this false notion.

Answer 86

ostracised and ill-treated

Question 87

Thalassemia:
is also an autosomal linked —- — disease transmitted when both the partners are — of the gene (heterozygous)

Answer 87

unaffected carriers

Question 88

Thalassemia could be due to —- or —- which ultimately results into reduced rate of —— that make up the —

This causes —– resulting into — which is a characteristic of this disease

Answer 88

mutation/ deletion
synthesis of any on of globin chains (alpha, beta)
haemoglobin

abnormal hb mol
anaemia

Question 89

Thalassemia can be classified acc to —-

Answer 89

which chain of hb is affected

Question 90

alpha Thalassemia is controlled by —- gene —– on chromosome — of — parent and it is observed dut to —- of one or more of the — genes
The more the genes get affected- the —- —- molecules produced

Answer 90

2 closely linked genes
HBA1, HBA2
16, each
deletion/mutation
4

less alpha globin

Question 91

Beta thalassemia is controlled by a —- gene —- on chromosome — of — parent and occurs due to — of —- of the genes

Answer 91

single
HBB
11- each
mutation of one or more

Question 92

Thalassemia differs from SCA in the former being —– of synthesising — hb mols while the latter is a —- problem of synthesising —– globin

Answer 92

quantitative
too few

qualitative
incorrectly synthesising