Genetics and Variation

Question 1

What is a fossil?

Answer 1

A fossil is one of the pieces of evidence towards the theory of evolution. It is the remains or impression of a prehistoric plant of animal embedded in rock and preserved in petrified form.

Question 2

What are the three types of fossils?

Answer 2

1. Impression fossils
2. Preserved organisms
3. Mineral replacement

Question 3

What is the process of fossil formation?

Answer 3

1. A plant or animal in water dies.
2. Its fleshy parts start to decay.
3. Mud and slit begins to cover it up.
4. Over time more layers of soil cover it up.
5. The encased bones decay and minerals seep in replacing the organic material cell by cell. This is called Petrification.
6. Geological activity distort the ground raising the fossil up.
7. Erosion reveals part of the fossil, which will be excavated.

Question 4

What is the definition of species?

Answer 4

It is a group of organisms that have characteristics in common and can interbreed to produce fertile offspring.

Question 5

What is natural selection?

Answer 5

Natural selection is the process where better adapted organisms (to the environment) tend to survive and pass on their genes (discovered by Charles Darwin).

Question 6

What is the process of natural selection?

Answer 6

1. Genetic variation due to genetic mutation.
2. They compete for better resources and to not be eaten by the predator.
3. The one that is better adapted to the environment wins.
4. More likely to survive and breed.
5. More likely to pass on the genes for next generation.

Question 7

What is Extinction?

Answer 7

Extinction is when no individual of a species remains.

Question 8

What are the causes of Extinction?

Answer 8

1. Environment changes quickly (eg. habitat destruction.
2. A new predator (eg. human hunting).
3. A new disease.
4. Competition with a new species for food.
5. A catastrophic event (eg. volcano erupting).

Question 9

What is a Allele?

Answer 9

Different forms of the same gene.

Question 10

What is the difference between a vertebrate and an in vertebrate?

Answer 10

Vertebrate is an animal with a back-bone and an invertebrate is an animal without a back-bone.

Question 11

What is a punnet square?

Answer 11

It is a table in where there are all the possible crosses between both individuals.

Question 12

What is a recessive trait?

Answer 12

A characteristic only expressed in the homozygous condition.

Question 13

What is homozygous?

Answer 13

Two copies of the same allele.

Question 14

What is heterozygous?

Answer 14

Two different alleles.

Question 15

What is an inherited gene?

Answer 15

It is a gene inherited from your parents.

Question 16

What is Petrification?

Answer 16

Petrification is the process by which organic matter exposed to minerals over a long period is turned into a stony substance.