Evolution: (Adaptations, Variations And Natural Selection)

Question 1

Survival:

Answer 1

•organisms that survive long enough to reproduce—> have the opportunity to pass genetic information to their offspring.
•advantageous adaptations improve the chance of survival.

Question 2

Adaptations:

Answer 2

•adaptation: a structure, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment.

Question 3

Structural or physical adaptations:

Answer 3

-a physical feature of an animal.
-a body part.
-ex) antlers, sharp teeth.

Question 4

Behavioural adaptations:

Answer 4

-an action done intentionally by an organism to ensure its survival.
-ex) migration, school of fish.

Question 5

Physiological adaptation:

Answer 5

-an involuntary action or change.
-involves the physiology of the organism.
-ex) sweating, skunk spray, venom.

Question 6

How do adaptations develop?

Answer 6

•result of a gradual change in the characteristics of members of a population over time.
•stem from RANDOM variations in the population.

Question 7

Variation within a species:

Answer 7

•variation: a visible or invisible difference between one individual and other members of a population.
•an advantageous variation that helps an organism survive will likely be passed onto offspring.
•over time, the adaptation will become more common in the population.

Question 8

Variations come from:

Answer 8

•1. Combination of parental genetic information.
•2. Genetic mutations.

Question 9

Selective advantage:

Answer 9

•mutations can provide a selective advantage: characteristic that improves an organisms chance of survival.
•eg. Slow growing houseflies resistant to the insecticide DDT.
•eg. California ground squirrels’ blood can combat rattlesnake venom. (Share the same habitat).

Question 10

Superbugs:

Answer 10

•in populations that reproduce quickly, like bacteria, viruses, and many insects, a rapidly changing environment can result in populations that adapt fairly quickly.
•staphylococcus “staph infection”.

Question 11

Staphylococcus “staph infection”:*

Answer 11

•aka “staph infection”.
•these cells appear to be identical, but some may have a mutation that makes them resistant to antibiotics.
•they reproduce asexually, by diving as frequently as every 20 minutes.
•one single cell can have close to a billion descendants in about 6 hours.
•due to this reproductive rate, this beneficial mutation makes it challenging for scientists to develop effective antibiotics.

Question 12

Natural selection:

Answer 12

•natural selection: a process that results when the characteristics of a population change because individuals with certain inherited traits survive specific local environmental conditions, and through reproduction, pass on their traits to their offspring.
•••
•”nature selects who will survive”.
•individuals did not change during their lifetime.
•populations change with the passage of time.
•environment exerts a selective pressure on the population.
•if NO individuals have traits with a selective advantage—> can lead to the species going extinct.

Question 13

Selective pressure:

Answer 13

•selective pressure: environmental condition that selects for certain characteristics of individuals and selects against others.

Question 14

Variation (combination of parental genetic information):

Answer 14

•Combination of parental genetic information:
•parents gametes randomly combine to produce offspring.
•variation is seen in a litter of kittens.
•variation is seen amongst you and your siblings.

Question 15

Variation (genetic mutations):

Answer 15

•2. Genetic mutations:
•mutation: change in genetic material of an organism.
•spontaneous.
•mutagens: cause mutations (example: UV light).
•can result in cell death, cell malfunctioning, uncontrolled cell replication (tumour).
•eg. Sickled cells.
•can be advantageous, disadvantageous, or neutral (no effect) for an organism.