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BZ110 FINAL Material
Ch. 7 The Reproductive Process
58
Biology
Undergraduate 2
05/10/2009

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Cards

Term

In what ways do organisms reproduce asexually?

(4 EXs)

Definition

1. Binary fission

2. Multiple fission

3. Budding

4.Fragmentation

Term

Hermaphroditism:

Definition

1. Both male and female organs in the same individual

2. occurs in many sessile, burrowing and/or endoparasitic invertebrates and some fish

3. most avoid self-fertilization

4. each individual produces eggs (can potentially produce twice as many offspring as dioecious species)

Term

 sequential hermaphroditism

(1 EX)

Definition

 a genetically programmed sex change occurs with an individual organism

 

EX: bluehead wrasse

Term

-          Monoecious: -         

Definition
containing both male and female sex organs
Term
Dioecious:
Definition
an organism has either male or female sex organs (separate sexes)
Term

-          Parthenogenesis: -    

(4 facts)     

Definition

1. development of an embryo from an unfertilized egg

2. avoids the energy and dangers of bringing two sexes together

3. narrows the diversity available for adaptation to new conditions

 

4. Amneotic parthenogenisis: egg forms by mitosis

Term

Haplodiploidy:

( 3 facts)

Definition

1. a type of sex determination in bees, wasps, and ants

2. fertilized eggs become diploid females (queens or workers) and unfertilized eggs develop parthogenetically to become haploid males (drones)

3. queen controls whether eggs are fertilized or unfertilized

Term

-          Gametogeneis: -    

Definition
gamete formation; includes spermatogenesis and oogenesis
Term
      Spermatogenesis: -         
Definition
sperm formation in the seminiferous tubules of the testes
Term
Oogenesis:
Definition

egg formation in the ovaries

 

primary oocyte is located within the follicles of the ovaries

Term

-          asexual reproduction advantages: -         

Definition
all genes get passed on to offspring
Term

Sexual reproduction advantages:

(3 facts)

Definition

1. Produce more novel genotypes to survive in times of environmental change

2. diversity prevents extinction

3. the more variation present, the less likely to become extinct

Term

How does Spermatogenesis occur: -         

Definition
the beginning sperm cell goes thru meiosis I and meiosis II and splits into 2 then 4 cells, each sharing the same amount of cytoplasm
Term
How does Oogenesis difoccur:
Definition

1. with a beginning egg cell, it goes thru meiosis I, and then cytokinesis, one of the duplicated cells get more cytoplasm and the other part of the cell becomes a small useless polar body (which will die)

2. then after meiosis 2, the big ovum duplicates again and the same thing happens; one egg will get more cytoplasm and the other and results in 2 polar bodies ( which will also die)

Term

How do oogenesis and spermatogenesis in humans differ?

Definition

-  in spermatogenesis four small same sized sperms are produced

- in oogenesis, one big egg is produced

Term

-          Testes: -         

Definition
male gonads
Term
seminiferous tubules: -         
Definition
location of sperm development
Term

interstitial cells (Leydig cells):

-        

Definition

located between lobules of testis

 

secrete testosterone

Term

-          scrotum: -         

Definition
hold the testicles
Term
epididimys:
Definition
Sperm pass from the testes to vasa efferentia and to coiled epididymis for maturation
Term

-          vas deferens: -         

Definition
carries sperm from the epididimys to the urethra
Term
prostate gland: -         
Definition
Secretes a milky, slightly alkaline solution that counters acidity of vagina
Term
bulbourethral glands:
Definition
Secretions provide lubrication and remove traces of urine from urethra
Term

-          seminal vesicles: -         

Definition
secrete a thick fluid containing nutrients for sperm
Term
urethra:
Definition

passes through the penis

 

conducts urine and sperm (not simultaneously)

Term

Why are human male testes not located in the abdominal cavity?

Definition

 Lower temperature of scrotum is vital to normal sperm production

Term

Describe functions of testosterone:

Definition

Growth of the penis, sperm ducts, and glands

also

Male sexual behavior

Term

-          Ovaries: -

(5 facts)         

Definition

female gonads

1. oocytes develop in a follicle

2. mature follicles rupture through wall of ovary

3. ovum released into the pelvic cavity

4. ~400k primary oocytes in ovaries at birth

5. only 300-400 reach maturity during “reproductive years”

Term
fallopian tubes: -         
Definition

 Also called oviducts

 

1. lined with cilia that draw the ovum into the oviduct and on to the uterus  

 

2. site of fertilization

Term
cervix: 
Definition
Region of the uterus that extends into the vagina     
Term

-          uterus: -  

( 2 EXs of the composition)       

Definition

site of implantation

 

1. endometrium:  Specialized highly vascular lining of the uterus

2. myometrium: Thick smooth muscle layer of the uterus

Term
vagina: -         
Definition
Muscular tube that receives the penis and serves as birth canal
Term
endometrium:
Definition
Specialized highly vascular lining of the uterus
Term

-          myometrium:

Definition
Thick smooth muscle layer of the uterus
Term

What are the functions of estrogen and progesterone?

Definition

  Both Estrogen and Progesterone are involved in preparing the uterus to receive an embryo

Term

-          Estrogen:

(3 facts)         

Definition

1. Development of  female accessory sex structures: oviducts, uterus and vagina

2. stimulates female reproductive activity

 

3. Development of Secondary sex characteristics: Bone development, Body hair, Initial development of mammary glands

Term

Progesterone:

(3 facts)

Definition

1. secreted by the corpus luteum and the placenta

 

2. prepares the uterus for the fertilized egg

 

3. maintains the capacity of the uterus to hold the embryo and fetus

Term

Follicular phase of the human menstrual cycle :-         

Definition

1. Day 1-13 

2. Rising blood levels of FSH(follicle stimulating hormone) and LH (lutenizing hormone)

a. Stimulates ovarian follicle growth

b. Estrogen secretion by follicles

Term

Luteal phase of the human menstrual cycle:

(4 facts)

Definition

Corpus luteum (remnants of ovarian follicle)

1. Day 15-28

2. Develops into an endocrine gland under the influence of LH

3. Secretes progesterone and estrogen

4. Stimulates uterus to undergo changes in preparation for gestation

Term

What stimulates ovulation?

Definition

A surge in LH and to a lesser extent, FSH which causes mature follicles to rupture and release ovum

Term

How do negative feedback mechanisms work if fertilization does not occur?

Definition

Negative feedback involving hormones of the hypothalamus, anterior pituitary, and ovary, control the cycle

Term

Why do changes in the uterus occur?

Definition

When fertilization does not occur, there is no need for the uterus, so the endometrium(lining of the womb) degenerates

Term

What is the corpus luteum and its function?

(4 facts)

Definition

1. Tissue that forms after ovulation

 

2. secretes the hormone progesterone  (and estrogen).

 

3. If no pregnancy is established, the corpus luteum degenerates

 

4. continues to secrete the hormone if pregnancy occurs

Term
What are the two components of sexual systems?
Definition

1. Primary organs: Gonads that produce sperm, eggs and sex hormones

2. Accessory organs: Assist gonads in formation and delivery of gametes and may support embryos

Term

 

Sertoli cells
Definition
nourish the developing sperm
Term

 

Vulva
Definition
External female genitalia
Term

 

Uterine Cycle
Definition
1. Menstrual Phase (Day 1-5)
2. Proliferative Phase (Day 6 – 15)
3. Secretory Phase (Day 16 – 28)
 
Term
Menstrual Phase
(2 facts)
Definition

(Day 1 – 5)

1. Due to low blood estrogen levels

2. Outer layer of endometrium degenerates and sloughs off

Term
Proliferative Phase
Definition

(Day 6 – 15)

1. As blood levels of estrogen rise
2. Endometrium heals and thickens
Term
Secretory Phase
(3 facts)
Definition
 (Day 16 – 28)
1. Uterus enters secretory phase if embryo implants
2. Progesterone secreted by the corpus luteum
3. stimulates activity of uterine glands
Term

blastocyst

(2 facts)

Definition

 1. Division of zygote as it travels to the uterus.

2. 6 days embeds in the endometrium (implantation) 
Term

Binary Fission

(4 facts)

Definition

 

1. Common among bacteria and protozoa

2. The parent cell divides into two halves

3. Each grows into an individual similar to the parent cell

4. Binary fission can be lengthwise or transverse

Term

Multiple Fission

(4 facts)

Definition

1. Nucleus divides repeatedly

 

2. Cytoplasmic division produces many daughter cells

 

3. Sporogony (Spore Formation)

 

4.Form of multiple fission in parasitic protozoa

 

Term

Budding

(3 facts)

Definition

1. Unequal division of an organism

2. A new individual arises as a bud, an outgrowth of the parent

 

3. Occurs in cnidarians and several other animal phyla

 

Term

Fragmentation

(2 facts)

Definition

1. Multicellular animal breaking into many fragments that become a new animal

 

 

2. Many anemones and hydroids

 

Term

Bisexual Reproduction

(3 facts)

Definition

1.Most common form

 

2. Produces offspring from union of gametes from two genetically different parents

 

3. Organisms are dioecious,

 

Term

Meiotic Parthenogenesis

(3 facts)

Definition

1. Haploid ovum formed by meiosis

 

 

2. Develops without fusion with male nucleus

 

 

3. Sperm may be absent or may only serve to activate development

 

Term
 Ovulation
Definition

(Day 14)

 

LH surge (and to a lesser extent FSH surge) causes mature follicle to rupture and release ovum

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