ACTIVITY 5 - VARIATION IN CLAMS

Question 1

Two important observations Charles Darwin made during his travels were?

Answer 1

(1) living things occupy a
planet that is constantly changing and
(2) living things change over time.

Question 2

These two observations led
him to the concept of ____ with ____

Answer 2

“descent with modification.”

Question 3

Darwin wrote that the presence of ____ within
species fuels the process of change over time—evolution.

Answer 3

variations

Question 4

variations within a species increase or decrease an individual’s chance of
_____.

Answer 4

Survival

Question 5

Whenever there is ___, there are winners and losers.

Answer 5

competition

Question 6

_____ ____ is a newly discovered species of clam. It had gone undiscovered until recently due to
its small size and the remoteness of the area it inhabits.

Answer 6

Clamys sweetus

Question 7

Two symmetrical shells connected by a ___ ____ protect its soft body.

Answer 7

Hinge joint

Question 8

C. sweetus, like other clams, eats ___ and in turn is eaten by small ___
and ___.

Answer 8

Plankton ; sharks and squid

Question 9

measure of the number of one strain that is present in the population
divided by the total number present multiplied by 100.

Answer 9

Percent frequency

Question 10

formula to compute for the percent
frequency

Answer 10

Percent Frequency = (specific clam strain / total number of clams) x 100

Question 11

Several years ago, a predatory ____ was accidentally introduced into the area inhabited by C.
sweetus.

Answer 11

arthropod

Question 12

The arthropod looks like a crab and has pincers specialized for ___open shells

Answer 12

Cracking

Question 13

Recent
studies indicate that C. sweetus has become its preferred food. In other regions of the ocean, the
arthropod primarily consumes
_____ clams.

Answer 13

soft-shelled