GENETICS UNIT

Question 1

Nucleus:

Answer 1

membrane bound control center of
cell containing X-shaped structures called
chromosomes. Each chromosome consists
of two chromatids held together by a
centromere.

Question 2

Chromosome:

Answer 2

X-shaped structure
consisting of a single DNA molecule.

Question 3

DNA Molecule:

Answer 3

consisting of genes, the
“code of life”

Question 4

Organism:

Answer 4

½ genes mom + ½ genes dad

Question 5

Interphase:

Answer 5

chromosomes can not be seen;
doubling of chromosomes; nuclear membrane
present; 99% of cell life.

Question 6

Prophase:

Answer 6

spindle fibers form; chromosomes seen
(randomly arranged).

Question 7

Metaphase:

Answer 7

chromosomes line up in the Middle,
no nuclear membrane.

Question 8

Anaphase:

Answer 8

chromosomes move Apart (Away)

Question 9

Telophase:

Answer 9

Two joined cells; two nuclear
membranes form

Question 10

Cytokinesis:

Answer 10

Two separated daughter cells form.

Question 11

Cell Division:

Answer 11

growth (embryo, fetus, infancy → adulthood) and
repair/maintanence of an organism

Question 12

Asexual Reproduction (ex: bacteria, hydra, worms):

Answer 12

simple life

Question 13

1 parent / 2 daughter cells

Answer 13

parent/daughter cells identical appearance
(genes)

Question 14

parent/daughter

Answer 14

cell same number of
chromosomes

Question 15

Sexual Reproduction (ex: animals, angiosperms)

Answer 15

Two parents (male, female)

daughter cells are a mixture/combination of
genes compared to parent cell (by crossover)

Question 16

parent to daughter

Answer 16

cell different number
of chromosomes

Question 17

Parent

Answer 17

2x chromosomes compared to
daughter cells

Question 18

Daughter

Answer 18

half (½) chromosomes
compared to parent cell

Question 19

Organism (offspring):

Answer 19

½ alleles mom; ½ alleles dad “stronger ”

Question 20

Mixture of our parents

Answer 20

(our dominant traits are usually
shown; only if both parents have recessive alleles will trait
be shown)

Question 21

Variety (variation)

Answer 21

allows the organism to be
better adapted to a changing environment.

Question 22

Variation

Answer 22

provides choices for SURVIVAL !!

Question 23

Cancer:

Answer 23

abnormal cell division; uncontrolled
mitosis; certain DNA mutations cause cells to
divide in an uncontrolled way.

Question 24

CAUSE -

Answer 24

Mutations are caused by:

1] Chemicals (carcinogens; ex: smoking,
gasoline, alcohol, fried foods)

2] Radiation (high dose; atomic bomb, nuclear
reactor meltdown Chernobyl (for Simon),
Ukraine)

3] Hereditary (ex: breast cancer)

Question 25

TREATMENT-

Answer 25

surgery, radiation, drugs,
immunotherapy.

Question 26

PREVENTION-

Answer 26

avoid smoking, eat healthy diet,
protect skin from bright sunlight. Vitamins may
help.

Question 27

Gene =

Answer 27

allele (dad) + allele (mom)

Question 28

Allele

Answer 28

(part of gene) = T or t

Question 29

Purebred (homozygous)=

Answer 29

same alleles (gene);
TT, tt

Question 30

Hybrid (heterozygous)=

Answer 30

mixture of alleles; Tt

Question 31

Dominant =

Answer 31

shows itself (strong); Tt, TT

Question 32

Recessive =

Answer 32

often hidden (weak); tt

Question 33

Offspring =

Answer 33

children

Question 34

Punnett Squares:

Answer 34

is a technique used to predict what
percentage of offspring (children) will be likely to
have a particular trait (physical feature).

Question 35

Trait:

Answer 35

physical (behavioral) feature of organism

Question 36

Gene =

Answer 36

allele (dad) + allele (mom)

Question 37

Allele (part of gene) =

Answer 37

T or t

Question 38

Hybrid (heterozygous)=

Answer 38

mixture of alleles (gene); Tt

Question 38

Purebred (homozygous)=

Answer 38

same alleles (gene); TT, tt

Question 39

Dominant =

Answer 39

capital and shows itself (strong); Tt, TT

Question 40

Recessive =

Answer 40

lowercase and often hidden (weak)
except when all alleles (genes) are recessive; tt

Question 41

Offspring =

Answer 41

children

Question 42

Genotype =

Answer 42

the genetic makeup of an organism

Ex: TT, Tt, tt

Question 43

Phenotype =

Answer 43

the physical observable appearance of
an organism. Ex: tall, short

Question 44

Trait:

Answer 44

physical feature on an organism

Question 45

Origin of organism’s trait =

Answer 45

½ Mom & ½ Dad

Question 46

Phenotype:

Answer 46

all traits;

Question 47

Mixture

Answer 47

of our parents (our dominant traits are
usually shown; only if both parents have recessive alleles
will trait be shown)

Question 48

Asexual Reproduction (ex: bacteria, worms):

Answer 48

1 parent / 2 daughter cells

parent / daughter cells identical
appearance(genes)

parent / daughter cell same number of
chromosomes

Question 49

Cell Division:

Answer 49

growth (embryo, fetus, infancy → adulthood) and
repair/maintanence of an organism

Question 50

Sex chromosome =

Answer 50

23rd chromosome pair

Question 51

Sex chromosome determines:

Answer 51

1] male/female

2] normal vs. red-green colorblind vision

3] with/ without hemophilia

4] muscular dystrophy other traits (sex-linked)

Question 52

Sex-Linked Genes:

Answer 52

genes carried on sex
chromosomes; example red-green colorblindness

Question 53

Carrier:

Answer 53

a person who does not show the observable trait but is
carrying the hidden recessive allele on the sex chromosome.

Question 54

Cystic Fibrosis:

Answer 54

mucus in lungs & intestines;
mutation (deletion) of 3 base pairs.

Question 55

Sickle-Cell Anemia:

Answer 55

sickle shape red blood cells
which can not carry much oxygen; co-dominant
allele.

Question 56

Hemophilia:

Answer 56

slow or no blood clotting; recessive
allele (sex-linked disorder).

Question 57

Down Syndrome:

Answer 57

extra copy of chromosome 21
causing a form of mental retardation;

Normal 21: II-shaped (2 chromatids)

Down Syndrome 21: III-shaped (3 chromatids)