Biology STAAR

For an enzyme to be able to catalyze a reaction, the active site must -

• cause the enzyme to be destroyed in the reaction

• increase the activation energy level

• be occupied by an inhibitor

• have a complementary shape to the substrate

An illustration of how a particular DNA mutation will most likely affect the polypeptide produced is shown. What type of mutation is illustrated?

• insertion

• translocation

• substitution

• deletion

Answer explanation

The original strand has a GTA coding for His. The mutated strand has a GGA which codes for Pro instead. The T got switched for a G, so this is a substitution.

Tags

NGSS.MS-LS3-1

Based on the cladogram, the ancestral species most likely had...

• a vertebral column

• a vertebral column and hair

• sharp teeth and retractable claws

• ability to purr

Answer explanation

Ancestral = oldest species that gives rise to the rest of the species. The ancestral species would lie to the far left, where only the vertebral column is.

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

When multiple transitional fossils are found in many rock layers, they provide evidence of -

• seasonal variation in the diet of a species

• gradual change of a species over time

• DNA functioning as the genetic material of organisms

• an unchanging environment

Answer explanation

transitional = CHANGE. Look for the answer choice talkig about change occurring.

Tags

NGSS.MS-LS4-1

The DEFENSES of 2 flightless birds that live in different habitats are shown. How do the wings of the Gentoo penguin and the legs of the ostrich provide an advantage in their habitat?

• Allows them to find prey

• Allows them to escape from predators

• Allows them to control body temperature

• Allows them to be camouflaged in their environments

Answer explanation

You can narrow down the answer choices to either "finding prey" or "escaping predators." Note that the question says the birds need DEFENSES and are FLIGHTLESS. Defenses are used to escape predators, not to hunt.

Tags

NGSS.MS-LS4-4

Photosynthesis takes in ​ (a)   and spits out ​ (b)   . Cellular respiration takes in ​ (c)  

• light energy

• chemical energy

Tags

NGSS.MS-LS1-6

Overfishing is when fish are caught faster than they can reproduce, causing the decline of fish populations. Overfishing ​ (a)   the stability of the ecosystem by ​ (b)   .

• increases

• disrupting food chains

• decreases

• increasing competition for limited resources

• allowing prey populations to overproduce

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Reorder the following species from oldest to youngest.

• turtle

• tiger

• horse

• wolf

• house cat

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

Reorder the following traits from oldest to youngest.

• retractable claws

• four limbs

• hair

• vertebral column

• sharp teeth

Tags

NGSS.MS-LS4-1

NGSS.MS-LS4-2

Eukaryotic cells have ​ (a)   and DNA in the ​ (b)   . Prokaryotic cells have ​ (c)   and DNA in the ​ (d)   .

• membrane-bound nuclei or organelles

• nucleus

• NO membrane-bound nuclei or organelles

• cytoplasm

Tags

NGSS.MS-LS1-2