Reproduction

Question 1

cell division

Answer 1

process by which a cell doubles its organelles & cytoplasm, replicates its DNA, and then divides in two

Question 2

unicellular organisms cell division

Answer 2

means of reproduction

Question 3

multicellular organisms cell division

Answer 3

method of growth, development, and replacement of worn-out cells

Question 4

types of cell division (2)

Answer 4

mitosis & meiosis

Question 5

mitosis (2)

Answer 5

• division and distribution of cell’s DNA to its daughter cells such that each cell receives a complete copy of the original genome
• preserves diploid number

Question 6

nuclear division is followed by ______

Answer 6

cytokinesis

Question 7

interphase

Answer 7

a period of growth and replication of genetic material

Question 8

sister chromatids are held together at

Answer 8

centromere region

Question 9

TRUE/FALSE: individual chromosomes are visible during interphase

Answer 9

FALSE; DNA is uncoiled (chromatin)

Question 10

parts of interphase

Answer 10

G1, S, G2, M

Question 11

G1 phase

Answer 11

• initiates interphase; cell increases in size & synthesizes proteins
• length determines the length of the entire cell cycle

Question 12

S phase

Answer 12

DNA synthesis

Question 13

G2

Answer 13

cell prepares to divide; growth & synthesis of proteins

Question 14

M

Answer 14

cell (nuclear) division occurs (prophase; metaphase; anaphase; telophase)

Question 15

Prophase (3)

Answer 15

• chromosome condense
• centrioles separate & move toward to opposite poles of the cell
• nuclear membrane dissolves

Question 16

Metaphase (2)

Answer 16

• fibers of the spindle apparatus attach to each chromatid at centromere
• chromosomes align at the center of the cell

Question 17

Anaphase (2)

Answer 17

• centromeres split allowing chromatids to separate

- spindle fibers shorten

Question 18

Telophase (3)

Answer 18

• spindle apparatus disappears
• nuclear membrane forms around each set of chromosomes
• chromosomes uncoil

Question 19

cytokinesis

Answer 19

division of cytoplasm

Question 20

meiosis (2)

Answer 20

• sex cells are produced

- produces haploid cells (halve # of chromosomes)

Question 21

asexual vs. sexual reproduction

Answer 21

sexual reproduction involves 2 parents

Question 22

homologous chromosomes

Answer 22

chromosomes that code for the same traits

Question 23

crossing over

Answer 23

when homologous chromosomes break at corresponding points and exchange equivalent pieces of DNA

Question 24

recombination among chromosomes results in ______

Answer 24

increases genetic variation

Question 25

what phase does crossing over occur in meiosis?

Answer 25

prophase

Question 26

disjunction

Answer 26

- homologous pairs separate and are pulled to opposite poles of the cell - random distribution to daughter cells

Question 27

sexual production requires

Answer 27

- production of functional cells (gametes) - union of these cells to form a zygote - development of zygote into an adult

Question 28

male vs female gonads

Answer 28

male: in the testes (sperm) female: ovaries (oocytes)

Question 29

gonads

Answer 29

where gametes are produced

Question 30

spermatogenesis

Answer 30

sperm production in the seminiferous tubules | (1) 2n -> (4) n cells

Question 31

oogenesis

Answer 31

production of female gametes in the ovaries | (1) 2n -> 1 egg cell+ polar body

Question 32

fertilization

Answer 32

union of the egg and sperm to form a zygote

Question 33

internal fertilization (2)

Answer 33

- provides direct route for sperm to reach the egg cell | - increases the chance of fertilization

Question 34

the amount of parental care is ______ related to the number of eggs produced

Answer 34

directly; species that care for their young produce fewer eggs

Question 35

scrotum

Answer 35

- external pouch that holds the testes (testosterone production) - maintains the testes temp at 2-4 degree Celsius lower than body temp

Question 36

route of sperm

Answer 36

testes-> vas deferens -> ejaculatory ducts -> uretha

Question 37

process of spermatogenesis

Answer 37

spermatogonia differientiate into primary spermatocytes (2n) -> secondary spermartocytes 2x(n) -> spermatids 4x(n) -> spermatozoa

Question 38

acrosome

Answer 38

caplike structure that contains enzymes needed to penetrate the tough outer covering of the ovum

Question 39

ovaries (2)

Answer 39

- found in the abdominal cavity | - consist of thousands of follicles (multilayered sac of cells)

Question 40

Once a month an immature ____ is released from the ovary into the _________ _______ and drawn into the nearby oviducts (fallopian tubes). Each fallopian tubes opens up into _____, which is the site of fetal development. The lower end is called the _____

Answer 40

ovum; abdominal cavity; uterus; cervix

Question 41

TRUE/FALSE: at birth all of the immature primary oocytes that a female will produce are already in her ovaries. which are produced by mitosis.

Answer 41

TRUE

Question 42

TRUE/FALSE: meiosis II occurs right after meiosis I during oogenesis

Answer 42

FALSE; it doesn't occur until fertilization. its triggered when the layers of the ovum are penetrated

Question 43

2 layers of the ovum

Answer 43

zona pellucida & corona radiata

Question 44

the secretion of both estrogen & progesterone are regulated by

Answer 44

LH (luteinizing hormone) & FSH (follicle stimulating hormone) which in turn are regulated by GnRH (gonadotr

Question 45

what plays an important role in the female reproductive cycle (3)

Answer 45

- hormonal secretion of the ovaries - hypothalamus - anterior pituitary

Question 46

phases of the menstrual cycle (4)

Answer 46

follicular phase, ovulation, luteal phase, menstruation

Question 47

follicular phase

Answer 47

FSH from the anterior pituitary promotes the development of the follicle, which grows and secretes estrogen

Question 48

ovulation (2)

Answer 48

- mid way through the cycle a mature ovarian follicle bursts and releases the ovum - peak in LH

Question 49

luteal phase

Answer 49

LH induces the ruptured follicle to develop into the corpus luteum (secretes estrogen & progesterone)

Question 50

menstruation (fertilized vs not fertilized)

Answer 50

- ovum fertilized: placenta produces hCG maintaining the corpus luteum and supply of hormones until placenta takes over production of hormones - ovum not fertilized: corpus luteum atrophies; endometrium slough off giving rise to menstrual flow

Question 51

purpose of the fertilization membrane

Answer 51

surrounds the ovum cell membrane and prevents multiple fertilizations

Question 52

monozygotic twins

Answer 52

identical twins: single zygote splits into 2 embryos

Question 53

dizygotic twins

Answer 53

fraternal twins: when 2 ova are released in one ovarian cycle and are fertilized by 2 different sperms