Biology- Evolution

Question 1

Species

Answer 1

A group of organisms that can successfully interbreed (success= can produce fertile offspring)
E.G- horses and donkeys are a separate species because when they mate, their offspring (mule) is infertile

Question 2

How do Mutations and Sexual Reproduction relate?

Answer 2

Mutations and Sexual Reproduction (if applicable) can make individuals in a population vary
E.G- hair, eyes, ski colour, height

Question 3

How can mutations be classified?

Answer 3

Mutations can be classified based on how they impact fitness (measure of an individual’s reproductive success)
E.G- # of fertile offspring they produce

Question 4

Mutations can be classified as 3 things. What are they?

Answer 4

1. Neutral- no impact on fitness
2. Beneficial- increase an individual’s fitness (better chance of reproducing and passing on mutation) –should be common in population
3. Harmful- decrease an individual’s fitness (lower chance of reproducing and passing on on mutation)–should be rare in population

Question 5

Artificial Selection

Answer 5

humans choose which individuals can mate based on the presence of human-desired traits

e. g- in each generation, only allow individuals with the desired trait to produce offspring–over many generations, traits becomes common
e. g- domestication of dogs from wolves, beginning at least 15 000 years ago
e. g- selective breeding of wild sea cabbage to make broccoli, cauliflower, cabbage and kale

Question 6

Problems with Artificial Selection

Answer 6

• Limits genetic diversity; individuals become more similar (have some weakness, less able to adapt to change)
• Human-preferred traits aren’t always best for the animal (e.g- farm cows, chickens, pugs)
• may be unintentional selection:
  e. g- selecting coat colour in dalmations also selects for problems in urinary system (genes are linked)
  e. g- unintentional selection for antibiotic resistance in bacteria (through overuse of antibiotics)