Reproduction

Question 1

Define Reproduction

Answer 1

The biological process by which new individual organisms are produced from their parents

Question 2

Define sexual reproduction

Answer 2

Typically requires the involvement of two individuals or gametes one each from the opposite type of sex

Question 3

Define gametogenesis

Answer 3

The process of differentiation of the primordial germ cell into gametes (egg and sperm)

Question 4

Define primordial germ cells

Answer 4

Early embryonic cells that acquire the developmental potential to develop into the gametes

Question 5

Define oogenesis

Answer 5

Egg development

Question 6

Define spermatogenesis

Answer 6

Sperm development

Question 7

What are the general characteristics of egg cells?

Answer 7

• large and non motile
• stores proteins, nucleic acids, ribosomes, RNA, mitochondria
  -yolk(energy supply)
• totipotent( developmental potential to develop into any cell type of the organism)
• unique haploid genome
• egg coat (protective coat, jelly coat)
• cortical granules( specialized golgi structures that protect the egg against polyspermy)

Question 8

Functions of the egg

Answer 8

• provides half the genome
• provides mechanisms for sperm recognition (ex.prevention of polyspermy)
• provides the raw materials to carry out early development

Question 9

Characteristics of sperm

Answer 9

• unique haploid genome
  -small and motile (flagella)
• few organelles( mitochondria, centrioles)
• acrosomal vesicle ( specialized golgi structure used by sperm to bind to and penetrate the egg coat)

Question 10

Function of sperm cells

Answer 10

• get to and fuse with egg
• contribute half the genome
• activates the egg

Question 11

Define gametogenesis

Answer 11

The development of diploid cells into either haploid eggs or sperm
Entails: genomic events, mitosis ,meiosis, specialization events

Question 12

Genomic events examples show …..

Answer 12

The fate of the cells that will become the germ cells is fixed early in development

Question 13

Define PGCs

Answer 13

Precursor germ cells or gonocytes are primordial germ cells that still have to reach the gonads and divide repeatedly on their migratory route

Question 14

What are the two structures that are initially present in the undifferentiated gonad?

Answer 14

Wolffian- male internal genitalia
Mullerian - female internal genitalia

Question 15

What is the purpose of mitosis in the process of gametogenesis?

Answer 15

Expansion of the primordial germ cell population

Question 16

What is the purpose of meiosis during gametogenesis ?

Answer 16

Development of diploid germ cells into either haploid eggs or sperm for sexual reproduction

Question 17

Define mitosis

Answer 17

Occurs in somatic cells, chromosomal number is not halved

Question 18

Define Meiosis

Answer 18

The process by which the number of chromosomes in a cell nucleus is halved during the formation of germ cells

Question 19

What are the benefits of sexual reproduction?

Answer 19

Meiotic recombination and fertilization produces offspring of varied genotypes and may enhance reproductive success when environmental factors change rapidly

Rearrangement of genes in population may allow them to remove harmful genes and may enhance adaptation

Question 20

In what two ways is variation generated during meiosis?

Answer 20

Chromosome segregation (independent assortment)
Crossing over ( homologous recombination )

Question 21

Define chromosomes

Answer 21

Structures that contain DNA

Question 22

Define DNA

Answer 22

Genetic info in a cell that is backed in a system of coiling and folding

Question 23

Define genes

Answer 23

Stretch of DNA that codes for something (ex. Proteins)

Question 24

In a cell with 4 chromosomes, how many sister chromatids are visible at the end of telophase/cytokinesis?

A) 0
B) 4
C) 8
D) 16
E) 2

Answer 24

A) 0

Question 25

How much genetic material is present in a cell during anaphase 1 compared to a cell during metaphase ? A) the same amount B) one-quarter as much C) four times as much D) one half as much E) twice as much

Answer 25

A) the same amount

Question 26

Primary germ cell produce(egg)…..

Answer 26

Oogonia

Question 27

Oogonia reproduce by _to produce…

Answer 27

1. Mitosis 2. Primary oocytes

Question 28

Primary ooctyes begin meiosis then….

Answer 28

Arrest at prophase 1. These cells are present in females at birth and reside in a follicle

Question 29

At puberty what hormone stimulates follicles to grow and mature ?

Answer 29

FSH( follicle stimulating hormone )

Question 30

Define ovulation

Answer 30

The breaking open of the follicle to release the secondary oocyte

Question 31

Define fertilization

Answer 31

Fusion of haploid sperm nucleus with haploid egg nucleus

Question 32

What does the corpus luteum( female reproductive organs) do?

Answer 32

Forms from the ruptured follicle and reduces progesterone which thickens uterus lining for pregnancy It degenerates if fertilization does not occur

Question 33

Define polar body

Answer 33

Small haploid cell formed from uneven division during cytokinesis during meiosis in oogenesis

Question 34

In humans puberty is triggered by…

Answer 34

Hormones in the hypothalamus and pituitary

Question 35

Where do testes develop ?

Answer 35

In the abdomen and descend into the scrotum

Question 36

Define seminiferous tubes

Answer 36

Network of tubules located in the testes

Question 37

Define Sertoli cells

Answer 37

They form the walls of seminiferous tubules; support germ cells

Question 38

Define leydig cells

Answer 38

They are adjacent to seminiferous tubules and produce androgens ( eg testosterone)

Question 39

What is the function of the acrosome in the sperm cell

Answer 39

It is a vesicle with enzymes that facilitate egg penetration

Question 40

What is the function of the mitochondria in the sperm cell?

Answer 40

Provide ATP for tail movement/ swimming

Question 41

What is inhibit

Answer 41

A peptide hormone secreted by the follicular cells of the ovary and the sertoli cells of the testis that inhibits secretion of follicle stimulating hormone from the anterior pituitary

Question 42

Define Oogonia

Answer 42

Mitotically active cells that produce primary oocytes

Question 43

Define secondary oocyte

Answer 43

The large cell produced by the first meiotic division

Question 44

Define ovum

Answer 44

The haploid cell produced by meiosis that becomes a functional gamete

Question 45

Define spermatogonia

Answer 45

Mitotically active cells in the gonads that give rise to spermatocytes

Question 46

Define spermatids

Answer 46

The four haploid cells produced by the meiotic division of a primary spermatocyte

Question 47

Cytokinesis of meiosis 1 is ...resulting

Answer 47

uneven, resulting in one small cell (the first polar body) and another larger cell