9A: Sexual and asexual reproduction

Question 1

In which types of organisms does asexual reproduction occur?

Answer 1

Only in unicellular and simple multicellular organisms

Question 2

Name 6 types of asexual reproduction

Answer 2

Binary fission, budding, fragmentation, vegetative propagation, sporogenesis, parthenogenesis

Question 3

Explain budding.

Answer 3

New individuals develop as outgrowths or buds from parent (hydra, sponges, flatworms), and break off as an independent individual.

Question 4

Explain fragmentation.

Answer 4

When a parent organism can be divided in many pieces to develop into a complete individual (starfish, flatworm) - head regrows

Question 5

Explain vegetative propagation.

Answer 5

Allows plant to reproduce without seeds
Vegetative section of plant (roots, leaves) break away from original plant and independently grows into new plant. (stem cutting, root cutting called breakaway section)

Question 6

Explain sporogenesis.

Answer 6

Occurs in plants, fungi, algae
Spores on the surface of organism is dispersed into surroundings by water/air and can grow into larger, multicellular haploid organism called a sporeling.

Question 7

What is sporulation?

Answer 7

Production of spores by bacteria when conditions are harsh, and can remain dormant until favourable conditions.

Question 8

What is the difference between a spore and an endospore?

Answer 8

Spores are reproductive structures produced by various organisms
Endospores are a specific type of spore produced by certain bacteria for survival in adverse conditions.

Question 9

Explain parthenogenesis.

Answer 9

Rare form where embryos can develop from only female gamete (occurs in bees, komodo dragons)

Question 10

List 4 advantages of asexual reproduction.

Answer 10

• populations grow faster
• as phenotypes are identical to parent, important for organism who has adapted to survive particular environment
• does not require finding a mate
• requires little parental investment (removes need to protect fragile offspring)

Question 11

What is a disadvantage of asexual reproduction?

Answer 11

Low genetic diversity - populations may suffer during rapid environmental change

Question 12

What are the gametes in a flower?

Answer 12

Pollen - male gamete
Carpel - female gamete

Question 13

How does pollen transfer occur?

Answer 13

Biotic - insects + birds are attracted to bright colours + smell, and pollen gathers on fur and taken to next flower.
Abiotic - wind, water (allows plant to focus on maximising pollen dispersion rather than attracting pollinators)

Question 14

List 3 advantages of sexual reproduction.

Answer 14

• increases genetic diversity (recombinant offspring)
• improves disease resistance
• reduces risk of genetic disorder (carriers, rec/dom notation)

Question 15

List 4 disadvantages of sexual reproduction.

Answer 15

• cost of male progeny
• time/money to find mate
• risk of STD’s
• risk of losing offspring to outside influences (embryo damage)