Variation, Classification And Inheritence

Question 0

What cause variation?

Answer 0

The exchange of genes during meiosis and various mutational events are some of the causes of variation . The other cause of variation is due to the high degree of neutrality of most mutations.

Question 1

Why are members of the same species different?

Answer 1

They have different DNA.

Question 2

What is natural selection?

Answer 2

Natural selection occurs naturally. Species adapt to their environment through random genetic mutations.

Question 3

What is artificial selection?

Answer 3

Artificial selection is purposefully breeding species to get desired traits.

Question 4

What are the 5 vertebrate groups?

Answer 4

Fish
Amphibians
Reptiles
Birds
Mammals

Question 5

What are the features of fish?

Answer 5

1. Fish are ectothermic, aquatic vertebrates.
2. Their skin is generally covered with scales.
3. Their limbs are modified into fins for swimming.
4. They breathe with gills.
5. They lay eggs that must be in water.

Question 6

What are the features of amphibians?

Answer 6

1. Amphibians are ectothermic vertebrates.
2. Their skin lacks scales, hair, and feathers, and is either smooth (like a frog) or rough (like a toad). They are dependent upon moisture and subject to desiccation; their skin must remain moist to aid in breathing.
3. They lay eggs in water, which hatch into an intermediate life form (tadpole or larva) that usually breathes with gills, and change into the adult form that breathes air and can live outside water.
4. They have three-chambered hearts.
5. They lack claws on their toes.

Question 7

What are the features of reptiles?

Answer 7

1. Reptiles are ectothermic vertebrates.
2. Their skin has scales, but no hair or feathers.
3. They have three-chambered hearts (except for alligators and crocodiles, which have four-chambered hearts).
4. They have claws on their toes (except those which do not have legs, such as legless lizards).
5. They are the first animals, in evolution, to develop the amniotic egg. This allows reptiles to lay eggs on land.

Question 8

What are the features of birds?

Answer 8

1. Birds are endothermic vertebrates.
2. Their skin is covered with feathers.
3. They have four-chambered hearts.
4. Their bones are lightweight and usually hollow.
5. Their forelimbs are modified as wings.
6. They lay eggs.

Question 9

What are the features of mammals?

Answer 9

1. Mammals are endothermic vertebrates.
2. They have hair, which varies greatly among species.
3. Most have sudoriferus (sweat) glands.
4. They have mammary (milk-secreting) glands.
5. They have sebaceous (fat-secreting) glands.
6. They have heterodont dentition (different types of teeth).