reproduction and hereditary unit

8/4/2019 Reproduction and Hereditary Unit

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- - - :Biology Reproduction and Heredity Test

Achondroplastic dwarf ism is a dominant genetic t rait that causes severe malf orm ation of the skeleton.

Homozygotes f or this condition are spontaneously aborted (h en ce, the homozygous condition is lethal) but

heterozygotes wil l develop to be dwarfed. V ':; > . / :.' ( / .

Matthew has a f amily history of the condition, although h e d oe s n ot e xp re ss the trait. Jane is an achondroplastic

dwarf . Matthew and Jane a re planning a family o f se veral chi ldren and \ ',1ant to know the chances of producingchild with achondroplastic dwarf ism.

I. Th e genotypes of Matthew and Jane a re bes t represented as: . ? t . -(

Matthew Jane l / .. -,

(A) AA Aa,1

(8 ) Aa I

~ ,'_f

aa

(C ) aa aa

(D) aa Aa

(E) Aa Aa

-, Th e p robability that Matth ew and Jane 's f irst child will be an achondroplastic d\varf is

(A) 0%

(8) 25%

(C) 50%

(D) 75%

(E) 100%

3. If three children are born to Matth ew a n d Jane, what are the chances that the fir st two children wil l not

cxpress the t rait b u t t hat the third child wi ll be an achondroplastic dwarf ?

(A) 5 / 8(8) 4 / 8

(C) 3 / 8

(D) 1 / 8

(E) 1 / 16

4. Which of the following c an be diagnosed by examining a karyotype oran individual's white bl~,<< j)dcells

(A ) Sickle cell anemia 'if'

(8) Alzheim er disease

(C) Dow n syndrome

(D) Cystic fibrosis(E) Ouchenne muscular dys trophy

S. \ Vhich of the following mutations would be most l ikely to have a harm f ul ef f ec t on an organism'!

(A ) A base-pair substitution

(8) A deletion of three nucleotides near the middle of a gene

(C) A single nucleotide deletion in th e m id dle of an intron

(D) A single nucleotide deletion near the end of the coding of the coding sequence

(E) A single nucleotide inseI1ion downstream of, and close to, the start of the coding sequ ence



(). Two genes, A and 8, are linked. An individual ,,'!-to j- Aa 8b produces equal numbers of f our game.

AB, Ab, aR and ab. T h e best explanation f or thi \ \ 'ou ld be that "-

(A) ondisjun tion occurred

(B) The genes are on homologous chromosom es

(C) Th e genes are onnonhomolog us chromosomes

(D) The two genes a re c lose together on the same hromo som e.

(E) Th e tw o g enes are separated by a large distan e on the sam e chromosome

7. A coup le has 5 children, all sons. If the \ \ 'oman gives birth to a sixth child, what is the probability that the

sixth c hild w ill be a s on?

(A) 5 / 6

(B) 1 / 2

(C) 1 / 5

(D) 1 / 6

(E) 1 / 64

(A) 0

(B) 1 / 16(C) 1 / 4

(D) 1 / 2

(E) 3 / 4

culture of white-eyed fi'uit fl ies (Dr os ophil a IIlelall og aster) w a s maintained f or m a ny generations. Females

m the stoc k w hite-e ye d c ulture were cro ssed with r ed-eyed (wild-type) males. The F 1 f emales were crossed

h the white-eyed males f<ten~tlI igiIialseLlIrCi~ Th e resulting ph enotype s of t he progeny are sum marized

ow .

ite-eyed f ema les x red-eyed males)(1 i) of f emales are red-eyed

( Y u of males are \ Vhite-eyed

red-eyed fem ales x white-eyed males

%) of f emales are red-eyed and 50% arc white-e yed

%) of males are red-eyed and 50% are white-eyed



Ie best explanation f or the red-eyed F I females is

(A) mu tation

(8) culture contamination

(C) dominance

(D) multiple loci

(E) sex-influenced traits

12 . There are \vhite-eyed f emales in the f ] generation because

(A) white is a dominant allele

(B) the white allele is autosomal(C) a mutat ion has occulTed

(D) these F2 f em ales have two white alleles

(E) the white allele is located on the Y chromosom e

13. Whic h of the following best describes the mode of inheritance of eye color in the \ vhite culture'?

(A) Autosom al

(8) Dom inant

(C ) Located on the Y chromosom e

(D) Sex-linked

(E) Lethal

14. [n sheep, eye co lo r is controlled by a single gene with two a lleles . When a homozygous brown-eyed sheep

is cro ssed with a homo zygous green-eyed sheep. blue-eyed off spring are produced . If the blue-eyed sheep

are ma ted with each other, what percent of their of f spring wil l most l ikely have brown eyes')

(A) 0%

(8) 25%

(C) 50%

(D) 75%

(E) 100%

15,[n peas the trait for tall plants is dominant

(7)and the trait for short plants is recessive

(I).The trait f oryellow seed co lor is dominant (Y ) and the trai t for green seed color is recessive (y). A cross between t \ \ 'O

plants resu lts in 296 tall yellow plants and 104 tall green p lants. Which of the following are mo st likely to

be the genotypes of the parents?

(A) TTYY x TT Y Y

(8) TT y )' x Tn ~ )'

(C) Tt Yy x Tty)'

(D) Tl r : l ' x Tr y ,r

(E) Tt yy x Tn y

16. All of the following nitrogenous bases are present in RN A E XC EPT :

(A) adenine(8) cytosine

(C) guanine

(D) thymine

(E) uracil



A) Random f ertilization

3) In dependent assortment

) Crossing ove r

0) Gene linkage

) R an dom gem; mutation

R , In the pedigree below, squ ares represent males and c ircles represent females. In di\ 'idua]s \\ '110 express a

particular t rait are represented by sha ded f igures. Which of the f ollo wing patterns ofinheriullce bestexplains the transmission of the trait'?

(A) Sex-linked d ominant

(B) Sex- linked recessive

(C) Autosom al recessive

(0) Autosomal dominant

(E) Incompletely dominant

9, T he f ath er m ust have which ofthe following bloo d types '?

(A ) A B o n ly

(B) Either AS or B

(C ) EitherABorO

(0) Either AB or A

(E) ABorAorO

. If the fath er has blood type AB, which of the following statements is correct ab ou t t he mother'?

(A) She contributes an I I ! allele, which is recessive to the f ather's I' allele.

(B) She contributes an iallele which is recessive to the father's II allele.

(C ) Sh e contributes an 1 '1 allele which is codominant to the f ather's I' allele.

(0) Sh e contributes an allele that is co dominant to the father's lallele.

(E) She is homozygou s for t h e 1

1 3

allele.

the 1940's, Avery, Macleod, and McCarty transf ormcd noncn capsulatcd bactc ria into encapsulated f orm s

ow ing the no nencapsulated cells in a culture containing an ex tract mad e from dead encapsulated cells. Th e

nsf orm ed cells produ ced colonies of encapsulated bacteria. Three different procedu res an d their results arc

tlined below.

o ce du re I:

tra ct made frol11 dead encapsulated cells added to culture mediul11.onencapsulated bacteria added to culture medium.



_,'draCl made from dead encapsulated cells tre ated with protein-degrading enzymes bef ore adding extrac t to

u lturc mcdium.

N onencapsulated bacteria ad de d to cu i ture medi um .

Extract made from dead encapsulated ce lls treated with DNAse (an enzym e th at selectively destro ys DNA)

efore adding extract to culture medium.

Nonencapsulated b acteria added to culture medium.

1 . A reasonable conclusion to draw from the results of the experim ent is that

(A) DNA is the genet ic material

(B) DNA replication is semi conserva tive

(C) DNA is a double helix

(D ) DNA is translated into protein

(E) mutation is a change in the genetic material

2 . What was the purpose of treatin g the ex tract with protein-degrading enzymes in Procedu re ll'?

(A) To demonstrate th at th e tra nsforming factor is an enzyme

(B) To demonstrate th at th e tra nsform ing f ac tor is not a protein

(C) To destroy nu cleic acids in the extract

(D) To destro y a ny capsules in the extract

(E) To prevent the ex trac t from being contaminated by nonencapsulated bac teria

3 . What was the purpose of treatin g the extract wi th DNAse in Procedure III '?

(A ) To remO \ e the encapsulated bacteria f rom the extract

(B) To serve as a po sitive c on tro l b y demonstratin g that a protein in the extract is the transforming

f actor

(C) To serve as a neg ative control by demonstratin g that transform ation does not occur \\ ith out DNA

(D) To destroy enzy mes in the extract

(E) To destroy any capsules that might be in the extract

24. Which of the f ollo wing is an example of a missense mutation?

(A) A nu cleotid e and its partner are replaced with an "incorrect" pair of nuc leotides, whic h d estroys the

f unction of the f inal protein.

(B) A nu cleotid e pair is added into a gene, destroying the reading f rame of thc gcnetic mcssage.

(e) A nu cleotid e pair is lost from th e gene, des troying the reading frame of the genetic message .

(D) A frameshit1 mutation occurs, ultimately causing the production of nonfunctional proteins,

(E) A nu cleotid e pair substitution occurs, which causes the codon to code f or an amino acid that may not be

the "correct" one, although translation continues.



5. At the cnd of DNA replication, eachof the daughter lllolecules has one ukl slrand , derived nUIII llIe p"

strand of DNA , and one strand that is new ly synthesized. This explains why DNA replication is descriL

as:

(A ) Co nservative

(B) La rge ly conserva tive

( C) Nonconserva tive

(D ) Semi conserva tive

(E) Unconserva tive

6 . If red hair, blue eyes, and freckles were consiste nt ly inherited togethe r, the best explanation would be that

(A ) these traits are recessive characteristics

(B) both parents ha ve red hair, blue e ye s, and f reckles

(C) the genes for these traits are linked on the same chromosome

(D) gene duplications ha ve occurred

(E) these traits are dom inant to others

. The strand s that make u p D NA are antiparallel. This means that:

) The tw isting nature of DNA creates nonparallel strands.

) Th e 5' t o 3 ' d irection of one strand runs coun ter to the 5' to 3' direction of the othe r strand.

Base pairings create unequal spac ing betwe en the two DNA strands.

) One strand is pos itive ly charged and t he other is ne gative ly charged. On e strand contains only purines and t he other contains on ly pyrimidines.

. Yo u b rief ly expos e bacteria un dergo ing DNA repl ica tion to radioactive ly labeled nu cleotid es. \ Vhen you

centrif uge the DNA isolated from the bacteria, the DN A separates into two classes. One class of labeled

DNA includes ve ry large molecules (thousands or even m i ll ions of nucleotides long ), and the other include s

shor t s tretches of D NA ( seve ra l hundre d t o a f ew thousand nucleotides in le ngth). Th ese tw o classes of

DNA probably represent :

leading strand s an d O kazaki f ragments.

laggi ng strand s a nd O kazaki f ragments.

Okazaki f ragm ents a nd R N A prim ers .

) lead ing strands and RNA primers.

RNA primers and mitochondrial DNA.

. A euk aryo tic cell l acking telomcrase would

have a high probability of becoming cancerous.

produ ce Ok azaki fragments.

be unable to repair thymine dimers.

undergo a redu cti on in c hr omosom e length.

be hi gh ly sensitive to sunlight .

. A transcript ion unit that is 8,00 0 nu cleotide s long lllay use 1,200 nucleotides to make a proteinconsisting of 400 amino acids. This is best explained by the fact that:

many noncoding nucleotides ar e p rese nt i n m R NA.

there is redundancy and ambigui ty in the genetic code.

many nu cleotides are needed to code for each amino acid.

nuc leot ide s break off and a re l ost during the transcription process.

there are termination exon s near t h e b eginning of mRNA.

reproduction and hereditary unit

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