Bio Lecture Exam 3

Question 1

The chromosome number is halved by __ and restored by __

Answer 1

meiosis; fertilization

Question 2

the normal human karyotpe contains _ autosomes

Answer 2

22

Question 3

at the conlcusion of s phase in mitosis, a diploid cell with 40 chromosomes will have _ chromosomes and _ sister chromatids

Answer 3

40; 80

Question 4

what type of cell division do prokaryotes go through? explain your answer by comparing it to mitosis

Answer 4

Binary fission; mitosis only occurs in eukaryotes

Question 5

generally which phase of the cell cycle varies the most in length depending on the type of cell

Answer 5

G1

Question 6

Which of the following are characteristics of meiosis?

Answer 6

Haploid cells
Final cells have chromosome content n.

Question 7

identify the stage of mitosis shown in image a

Answer 7

interphase

Question 8

which process results in the production of offspring who are recombinant for two genes on the same chromosome

Answer 8

crossing over homo chromo

Question 9

a cell entering the cell cycle with 32 chromosomes will produce two daughter cells each with

Answer 9

32 chromosomes

Question 10

homologous chromosomes undergo recombination by exchanging segments during

Answer 10

prophase 1

Question 11

pairs of alleles; are found at a particular _ on a pair of _

Answer 11

base; homo chromo

Question 12

one type of cell cycle control signals is a

Answer 12

Cyclins

Question 13

why is mitosis necessary

Answer 13

growth; replace old or damaged cells

Question 14

if an intestinal cell ina grasshopper contains 24 chromosomes, a grasshopper sperm cell after undergoing meiosis would contain _ chromosomes

Answer 14

12

Question 15

when an indnividual has two different alleles for a given gene they are _ for that gene

Answer 15

heterozygous

Question 16

the daughter cells produced by meiosis are _

Answer 16

haploid

Question 17

chromosomes are in a condensed form at which stages of the cell cycle

Answer 17

metaphase

Question 18

nondisjunction during meiosis I might result in

Answer 18

down syndrome; abnormal gametes that contain two members of the affected chromosome or none at all

Question 19

the separation of duplicated chromosomes into two new nuclei is known as

Answer 19

mitosis

Question 20

identify the stage of mitosis in panel E

Answer 20

metaphase

Question 21

your father has type b blood, and your mother has type o blood. you learn that you also have blood type O. What does this tell you

Answer 21

Your father’s genotype is IBi and your mother’s genotype is ii.

Question 22

the main difference between bacterial cell division and eukaryotic cell division is that

Answer 22

Bacterial DNA replication and chromosome segregation are concerted processes but in eukaryotes they are separated in time.

Question 23

A parent has a genotype of RrYy. What is the probability of having a gamete with the RY genotype?

Answer 23

1/4

Question 24

following the completion of meiosis in animals, males produce _ sperm cells and females produce _ eggs

Answer 24

4; 1

Question 25

which statement best describes the difference between cell division in plant and animal cells

Answer 25

In animal cells cytoplasmic division is accomplished by “pinching in” of the cell membrane, while in plant cells a cell plate is synthesized.

Question 26

which sequence of the cell cycle is correct

Answer 26

G1 → S → G2 → M

Question 27

if you examine your karyotype and see 23 pairs of homologous chromosomes, explain what the homologues are

Answer 27

pairs of chromosomes that possess similar genetic information

Question 28

who was given the title of father of genetics

Answer 28

Gregor Mendel

Question 29

polygenic inheritance is often modified by

Answer 29

envrionment

Question 30

The ability of an individual heterozygous for two different genes to produce its four gamete types in equal numbers reflects Mendel’s Law(s) of…

Answer 30

Segregation and Independent Assortment

Question 31

after fertilization the newly formed zyogte Grows by

Answer 31

mitosis

Question 32

the cells in the human body that are produced by mitosis are

Answer 32

somatic

Question 33

when pairs of homologous chromosomes come together to form tetrads what occurs

Answer 33

synapsis

Question 34

sexual reproduction has an advantage over asexual reproduction by

Answer 34

genetic variability

Question 35

once human nerve cells become mature they normally exit the cell cycle and remain in

Answer 35

G0 phase

Question 36

genetic variability in meiosis results from

Answer 36

recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes

Question 37

what is the key difference between incomplete dominance and codominance

Answer 37

codom: no allele can block the expression of the other allele

incomp dom: a dom allele doesn’t completely block the effects of a recessive allele

Question 38

in snapdragons, the red allele cr is incompletely dominant over the whtie allele cw. if you cross a pink snapdragon with a white snapdragon

Answer 38

0%

Question 39

which type of aneuploidy is less detrimental? aneuploidies on the sex chromosomes or the autosomes. Why?

Answer 39

Sex; process of X-inactivation

Question 40

which disorder is an example of pleiotropy

Answer 40

phenylketonuria

Question 41

explain what the term polygenic inheritance means

Answer 41

inheritance of a trait due to more than one gene

Question 42

what would not happen in anaphase 1

Answer 42

splitting of centromere

Question 43

which statement describes a similarity between meiosis and mitosis

Answer 43

crossing over

Question 44

Your mother has albinism, which is a recessive trait. You learn that your spouse’s mother also has albinism. Neither you nor your spouse have albinism. What are the odds that your first child will have albinism?

Answer 44

1/4

Question 45

identify the stage of mitosis shown in panel B

Answer 45

Anaphase