Bio 111 Lab 9 Midterm Quiz

1. What are Cladocerans?

Small freshwater fish

Land snails

Aquatic crustaceans "water fleas"Important in food web because they prey on phytoplankton/bacteria and are eaten by other invertebrates like Hydra and vertebrates like fish.Ex. Daphnia magna

Marine algae

Cladocerans are aquatic crustaceans commonly known as water fleas, and are key players in aquatic ecosystems.

Explanation

Cladocerans are aquatic crustaceans commonly known as water fleas, and are key players in aquatic ecosystems.

2. What are some key features of Daphnia magna?

Long tail for swimming fast

Sharp claws for defense

Large tentacles for grasping prey

Brood pouch - contains 2-20 eggs which usually develop by parthenogenesis.posterior spine - reduce chance of being eaten by small predatorspost abdominal claw - removes debris from under carapaceThoracic legs - 5 pairs which generate water currents + filter feeding. Food gets trapped on filtering setae

Daphnia magna's key features include its brood pouch, posterior spine, post abdominal claw, and thoracic legs, which are essential for its survival and reproduction. Large tentacles, a long tail, and sharp claws are not characteristic features of Daphnia magna.

Explanation

Daphnia magna's key features include its brood pouch, posterior spine, post abdominal claw, and thoracic legs, which are essential for its survival and reproduction. Large tentacles, a long tail, and sharp claws are not characteristic features of Daphnia magna.

3. What is parthenogenesis?

Asexual!During favourable conditions only females are produced. During unfavourable conditions some eggs develop into males. Then there is sexual reproduction. Then, females (before death) make thick protective layer around the brood chamber w/ 2 fertilized eggs. The sac is molted and remains in the sediment until conditions improve.

A form of genetic mutation

A process of cellular respiration

A type of plant growth pattern

Parthenogenesis is a term used to describe the reproduction of offspring without fertilization, typically seen in some species of insects, fish, reptiles, and plants.

Explanation

Parthenogenesis is a term used to describe the reproduction of offspring without fertilization, typically seen in some species of insects, fish, reptiles, and plants.

4. What type of thermic regulation does Daphnia exhibit?

Heterothermic - able to switch between ectothermic and endothermic modes

Mesothermic - mix of ectothermic and endothermic characteristics

Endothermic - Heat is internal (from metabolism) ex. Birds/mammals

Ectothermic - heat comes from external sources (Daphnia)Endothermic - Heat is internal (from metabolism) ex. Birds/mammals

Daphnia is an example of an ectothermic organism, meaning it relies on external sources of heat to regulate its body temperature.

Explanation

Daphnia is an example of an ectothermic organism, meaning it relies on external sources of heat to regulate its body temperature.

5. What type of thermoregulation does Daphnia exhibit?

Endotherms - Generate internal heat to maintain body temperature

Ectotherms - Rely on external sources to regulate body temperature

Homeotherms can thermoregulate (maintain body at decent temperature)

Homeotherms can thermoregulate (maintain body at decent temperature)Poikilotherms - Can't thermoregulate. Changes w/ the environment.

Daphnia falls under the category of poikilotherms, which means they cannot regulate their body temperature internally and instead rely on external environmental factors for temperature control.

Explanation

Daphnia falls under the category of poikilotherms, which means they cannot regulate their body temperature internally and instead rely on external environmental factors for temperature control.

6. How is Q10 calculated and what does it show?

Q10 is only relevant for chemical reactions involving gases.

Q10 is calculated by subtracting the rate of a reaction at one temperature from the rate of the reaction at a temperature 10 degrees higher.

Q10 shows the sensitivity of a reaction to temperature.Calculate by dividing rate of a reaction at one temperature (Rt) by the rate of the reaction at a temperature 10 degrees lower (Rt-10)Ex. if temperature doesn't affect rate of reaction the Q10 will be one.If rate of reaction doubles w/ 10 degrees increase, the Q10 will be 2.

Q10 is a measure of enzyme activity.

Q10 is a calculation used to determine the sensitivity of a reaction to temperature changes, specifically by comparing the rate of reaction at different temperatures. It is not a measure of enzyme activity or only relevant for reactions involving gases. The correct formula involves dividing the rates at specific temperatures.

Explanation

Q10 is a calculation used to determine the sensitivity of a reaction to temperature changes, specifically by comparing the rate of reaction at different temperatures. It is not a measure of enzyme activity or only relevant for reactions involving gases. The correct formula involves dividing the rates at specific temperatures.

7. How can a bimodal distribution of beak sizes be achieved?

By feeding birds different diets to see if beak sizes change.

By randomly selecting birds and hoping for the best.

Tell me about it.

By modifying the beaks of existing birds through surgery.

A bimodal distribution of beak sizes can be achieved by selectively breeding birds with extreme beak sizes to create two distinct groups, rather than relying on random chance or external factors like diet or surgery.

Explanation

A bimodal distribution of beak sizes can be achieved by selectively breeding birds with extreme beak sizes to create two distinct groups, rather than relying on random chance or external factors like diet or surgery.

8. What does PC1 represent in the context of this study?

Beak size which is a composite of length, width, and depth.

Feather color

Nest building behavior

Wing span

PC1 specifically refers to the composite beak size measurements, which include length, width, and depth. It is not related to feather color, nest-building behavior, or wing span in this study.

Explanation

PC1 specifically refers to the composite beak size measurements, which include length, width, and depth. It is not related to feather color, nest-building behavior, or wing span in this study.