Theme 5 - Dr. Robinson

Question 1

What are the 4 types of asexual reproduction and give an example of each

Answer 1

1. Fission (splitting) - Flatworms
2. Budding (branching) - Hydra
3. Fragmentation - echinoderms
4. Parthenogenesis (Develop from unfertilized egg) - Rotifers

Question 2

What are the pros of asexual reproduction?

Answer 2

• Reproduce in isolation
• Reproduce rapidly

Question 3

What are the cons of asexual reproduction?

Answer 3

Less or no genetic variability as they are the genetic clone of the parent organism

Question 4

Does parthenogenesis result in a genetic clone of the parent species?

Answer 4

No, they’re not identical

Question 5

What is an example of parthenogenesis?

Answer 5

The whiptail lizard. All are female.

Question 6

What does dioecious mean?

Answer 6

Two houses. Egg OR sperm

Question 7

What does monoecious mean?

Answer 7

One house. Both egg and sperm

Question 8

What are the pros of sexual reproduction?

Answer 8

Genetic variability
More complex

Question 9

What are the cons of sexual reproduction?

Answer 9

Slower
Energetically costly

Question 10

What is spermatogenesis?

Answer 10

Produces sperm
Specialized to move toward and penetrate eggs

Question 11

What is an acrosome?

Answer 11

A secretory vesicle containing enzymes

Question 12

What is oogenesis?

Answer 12

Produces an ovum
Stored nutrients for early stages of development
Protective coating
Can be the largest cells in an animal

Question 13

What does the first stage in early development produce?

Answer 13

• A zygote

Question 14

What does early cleavage produce?

Answer 14

A blastula and a gastrula (tissue layers)

Question 15

What are the features of external fertilization?

Answer 15

Release eggs/sperm into the environment
Many gametes
small gametes

Question 16

What are the features of internal fertilization?

Answer 16

Male deposits sperm into the female
Mating behaviour/competition
Is an adaptation to terrestrial environments

Question 17

What does the “fast block” do?

Answer 17

prevents more sperm from entering the oocyte

Question 18

What is oviparous and what types of animals are oviparous?

Answer 18

Egg bearing, such as reptiles and insects

Question 19

What does viviparous mean and what is an example?

Answer 19

Embryo develops within the parent, such as in mammals

Question 20

What does ovoviviparous mean and what are examples?

Answer 20

Egg is kept within the parent, such as in some fish, lizards, and sharks

Question 21

What are the 5 steps in ontogeny (early development)?

Answer 21

1. Fertilization
2. Cleavage
3. Gastrulation
4. Organogenesis
5. Metamorphosis

Question 22

What happens in cleavage?

Answer 22

Mitosis, produce morula (solid ball of cells), then produce a blastula (hollow ball of cells)

Question 23

What happens in Gastrulation?

Answer 23

Cell divisions and migrations. Rearrangements produce a gastrula, an early embryo that has primary tissue layers

Question 24

What happens in Organogenesis?

Answer 24

Cell divisions, movements, etc produce the major tissues and organ systems, and a body organization characteristic of the species (neurulation)

Question 25

What is metamorphosis?

Answer 25

The animal develops into the adult with characteristic adult appearance and all tissues and organs carrying out their specialized functions

Question 26

What is an archenteron and in what stage is it found?

Answer 26

The digestive cavity of an embryo in the gastrula stage

Question 27

What is direct development and how is it different from indirect development?

Answer 27

Direct development is when the young looks like a smaller version of the parent (dogs) and indirect development the young looks nothing like the adult (tadpoles)

Question 28

Are cells getting bigger during cleavage?

Answer 28

No. There is no new cytoplasm, they are just undergoing many mitotic divisions until they become a morula and later a blastula

Question 29

Is the blastula empty or filled with fluid?

Answer 29

Filled with fluid

Question 30

What are the 6 mechanisms of gastrulation?

Answer 30

1. Mitosis 2. Cell movement (selective) 3. Selective cell adhesion (stick together or break) 4. Induction (induce change in other groups) 5. Determination (brought by induction) 6. Differentiation (develop into diff tissues)

Question 31

Where does gastrulation begin?

Answer 31

at the vegetal pole, where mesenchyme cells (future mesoderm) break loose and migrate into the blastocele

Question 32

What are the 4 stages of frog gastrulation?

Answer 32

1. Blastula 2. Gastrulation begins, cells start to invaginate 3. Cells migrate into blastopore (develop archenteron) 4. Movement of animal half cells encloses vegetal half cells (yolk plug)

Question 33

What happens during chordate neurulation?

Answer 33

Neural plate forms as thick regions f ectoderm along dorsal midline. Centre of neural plate sinks and edges elevate. Centre sinks further and edges move together. Edges fuse, closing neural tube. Neural tube pinches free and ectoderm closes over tube.