Question

question 20 (multiple choice worth 4 points)
(06.03 mc)
as hominids evolved, they created increasingly sophisticated tools. based on this information, which of the following is the best inference that can be made?

• as their cognitive abilities increased, the size of their brains also increased.
• in order to communicate how to make the tools, they must have been capable of language.
• developing tools facilitated the transition to walking upright.
• using tools enabled them to obtain food, so their weight - to - height ratio also increased.

question 21 (multiple choice worth 4 points)
(05.04 mc)
based on the concept of phylogeny, an organism that was ancestral to both the bacteria and eukaryota domains would exhibit which of the following characteristics?

• it would have mitochondria and other membrane - bound organelles.
• it would have dna.
• it would have a nucleus.
• it would have cell walls as well as cell membranes.

Explanation:

Question 20

To solve this, we analyze each option:

• Option 1: Tool sophistication in hominids' evolution is linked to cognitive (brain) development. As hominids evolved tools, their cognitive abilities (and brain size) likely increased, which is a valid inference.
• Option 2: Tool - making doesn't necessarily imply language ability (e.g., early tool - making could be through imitation without language).
• Option 3: Tool development and bipedalism (walking upright) have a less direct causal link compared to brain - tool relationship.
• Option 4: Tool use for food doesn't directly lead to a predictable weight - to - height ratio increase.

1. Recall phylogeny and domain characteristics:

• Bacteria are prokaryotes (no membrane - bound organelles like mitochondria or nucleus). Eukaryota have membrane - bound organelles.
• The common ancestor of Bacteria and Eukaryota would have characteristics common to both. DNA is a universal genetic material, so the ancestor would have DNA.
• Option 1: Mitochondria are membrane - bound organelles, and Bacteria lack them, so the ancestor can't have mitochondria.
• Option 3: Bacteria lack a nucleus, so the ancestor can't have a nucleus.
• Option 4: Not all Bacteria (and thus the common ancestor) have cell walls (e.g., Mycoplasma), so this is not a universal characteristic.

Answer:

A. As their cognitive abilities increased, the size of their brains also increased.

Question 21