Histology Lecture 4

Question 1

What is the aim of female odontcetes?

Answer 1

• Females single egg

- To rear successful offspring

Question 2

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Answer 2

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Question 3

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Answer 3

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Question 4

What is the aim of male odontcetes?

Answer 4

-To successfully mate with as many females as possible, to pass on as many genes to the next generation

Question 5

What do you when obtaining testis samples?

Answer 5

1. Measure length, width, weight of each testis
2. Obtain a cross section
3. Fix in formalin

Question 6

What are germinal cells?

Answer 6

Cells that make sperm

Question 7

Where are germinal cells found?

Answer 7

In the seminiferous tubules

Question 8

What are somatic cells?

Answer 8

Supportive cells

Question 9

What do sertoli cells do?

Answer 9

Nourish developing germ cells
Secretes and regulates hormones
Provides structure
Act as phagocytes

Question 10

What do leydig cells do?

Answer 10

Produce testosterone in the presence of luteinizing hormone

Question 11

What does testosterone do?

Answer 11

Stimulates the development of male secondary sex characteristics and spermatogenesis

Question 12

What stage is this tissue in?

Answer 12

Immature

Question 13

What does IM stand for?

Answer 13

Immature

Question 14

What does P stand for?

Answer 14

Pubescent

Question 15

What does RM stand for?

Answer 15

Resting Mature

Question 16

What does AM stand for?

Answer 16

Active mature

Question 17

Describe an immature common dolphin gonadal tissue

Answer 17

• Sertoli cells only ‘3’
• Interstitial tissue ‘3’
• Spermatogonia ‘1-2’
• Mitosis starting but scarce
• Epididymis is empty
• Diameter of tubule < 65 u

Question 18

Describe pubescent common dolphin gonadal tissue

Answer 18

• Meiosis starting
• Sertoli cells, interstitial cells, spermatogonia and spermatocytes present
• Diameter of tubule <82 u
• Epididymis empty

Question 19

What stage is this tissue at?

Answer 19

Pubescent

Question 20

What stage is this tissue at

Answer 20

Active mature

Question 21

Is this during the mating period or not?

Answer 21

Yes during the mating period

Question 22

Is this during the mating period or not

Answer 22

Not during the mating period

Question 23

Describe active mature common dolphin gonadal tissue

Answer 23

• Diameter of tubule <200 u
• Sertoli cells are rare
• Spermatids and spermatozoa’s are numerous
• Epididymis enormous with many spermatozoa

Question 24

Describe a resting mature common dolphin

Answer 24

• Tubules appear mature
• Large lumens, however a lot of sertoli and few germinal cells
• Spermatozas present, but on occasion, rare occurrence

Question 25

What stage is this tissue at?

Answer 25

Resting mature

Question 26

What stage is this pilot whale tissue at

Answer 26

Mature

Question 27

What stage is this pilot whale tissue at

Answer 27

Immature

Question 28

What stage is this pilot whale tissue at?

Answer 28

Maturing

Question 29

What happens to certain types of fish during sexual development?

Answer 29

Some fish undergo a sex change during normal development

Question 30

What is it called when male fish transform into females

Answer 30

Protandrous

Question 31

What is it called when female fish transform into males

Answer 31

Protogynous

Question 32

How does natural intersex fish benefit from this adaptation?

Answer 32

-They can optimise their reproductive output under various environmental conditions