lecture 7

Question 1

Prokaryotes

Answer 1

Primitive bacteria without a nucleus (no mitochondria, single-cell, asexual,)

ex: e.coli, salmonella

Question 2

Eukaryotes

Answer 2

includes a nucleus and product of sexual reproduction

Question 3

Asexual reproduction

Answer 3

Reproduces without sex (we do this naturally in mitosis). Pro: 100% of genes copied, requires less energy, less
likely to be preyed on when “mating”. Con: No genetic variability.

Question 4

Sexual Reproduction

Answer 4

Sex with sperm and egg
(meiosis).

Pro: genetic variability, so can adapt and change to fit the environment. DNA also can be repaired, survival may increase because of variation.

Con: Less safe, requires energy to mate and find mates, only half of genes

Question 5

Hermaphrodites

Answer 5

produce eggs and sperm in same organism and can sexually reproduce

Question 6

Simultaneous hermaphrodites

Answer 6

functioning male and female gonads, can self-fertilize

ex: snails, sponges

Question 7

Successive (serial) Hermaphrodisim

Answer 7

mature as one sex and transition later in the other sex

ex: clownfish

Question 8

Parthenogenesis

Answer 8

eggs laid by female developed without fertilization, asexual, no sperm needed

ex: honeybees

Question 9

Lottery Hypothesis

Answer 9

best practice is to have a variety of different genes in many different offspring

Question 10

Coevolution Hypothesis

variation and its benefits

Answer 10

animals with genetic variation will have more benefits

can adapt rapidly to changing predators

Question 11

Sex determination

Answer 11

Determined by XY or XX chromosomes

In birds, this is ZZ (male) or ZW (female). Homo/Heterogametic, sperm speed (y swims faster, more males but die more) we have one pair of sex chromosomes

Question 12

Sex determination by temperature

Answer 12

hotter temperature means more males, colder temperature means more females

specific to reptiles

Question 13

External Fertilization

Answer 13

fertilization happens outside of female’s reproductive tract

pros: Quicker, easy to find mates, lots of offspring, random gene diversity

con: More likely to be eaten (waste if already fertilized), may be time dependent, not all get fertilized

ex: fish and bullfrogs

Question 14

Internal fertilization

Answer 14

eggs are fertilized inside the female’s reproductive tract

pros: Protected, can be anywhere

cons: takes more time and energy from mother

ex: dogs, humans, mammals

Question 15

K Strategist

Answer 15

Quality care and longer growth/developmental phase with more care to offspring

Question 16

R Strategist

Answer 16

lots of offspring, unstable and short lifespans, quick growth