Genetics and Evolution Flashcards

Flashcards covering key genetics and evolution concepts from lecture notes.

What are the complementary base pairs in DNA?

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).

How many chromosomes do humans inherit from each parent?

23 chromosomes from each parent, for a total of 46 (23 pairs).

What is the definition of aneuploidy?

Aneuploidy is having one more or one less chromosome than the typical number.

What is the definition of polyploidy?

Polyploidy is having extra sets of chromosomes (e.g., triplets instead of pairs).

What is a gene?

A section of DNA that codes for a characteristic.

What are alleles?

Varied forms of a gene that code for the same trait (e.g., different alleles for eye color).

How are dominant alleles represented?

By capital letters.

How are recessive alleles represented?

By lowercase letters.

When are recessive alleles expressed?

Only when there is no dominant allele present.

What does "survival of the fittest" mean?

Individuals who are most suited to an environment will survive to pass their genes to the next generation.

What is a structural adaptation?

A physical appearance characteristic, like large ears or thorns.

What is a behavioral adaptation?

A behavior that an organism does to survive, like hibernation or blooming only at night.

What is a physiological adaptation?

Adaptations based on body chemistry and metabolism, such as toxins in plants or efficient kidneys in desert animals.

Give some possible adaptations for an albino animal including any possible disadvantages?

Light fur might reflect light and reduce heat absorption, but it may make an animal more visible to predators.

What are adaptations in plants?

Features that help the plant survive as a species.

How is seed dispersal by wind an adaptation?

It removes seeds from the parent plant, allowing access to new resources.

What is natural selection?

The process where organisms that best fit their environment survive and reproduce, passing on their genes.

What are selection pressures?

Environmental factors that species must survive, such as predators, prey, food availability, water availability, disease, and competition.

How does variation within a species affect its ability to survive?

Different features (characteristics/adaptations) can provide advantages or disadvantages under different selection pressures.

What are the basic steps of evolution due to natural selection?

Variation, selection, reproduction, and inheritance.

What is divergent evolution?

Evolution from the same common ancestor, where species develop different adaptations over time to fit their environment.

What's an example of divergent evolution?

Mammal limbs: cats (pouncing), humans (tool users), whales (swimmers), horses (runners) all have similar underlying bone structures but different forms suited to their functions.