Page 6 - ACE YR IGCSE A TOP APPROACH TO BIO

(b) State one physical feature that shows that Ornithorhynchus anatinus is grouped into the
class of mammals.

[1]

(c) Ornithorhynchus anatinus is an unusual mammal because it lays eggs, instead of giving
birth to the young. Laying eggs for reproduction normally belongs to which group of
vertebrates? Give two examples.

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[2]
[Total: 5]

Clone May / June 2011
2 Fig. 2.1 shows two species of spiders, Latrodectus hesperus and Steatoda nobilis.

Latrodectus hesperus Steatoda nobilis
Fig. 2.1

Latrodectus hesperus is commonly known as the Black Widow Spider, which is a deadly
venomous spider species. Steatoda nobilis has physical features similar to Latrodectus hesperus
but is non-venomous.

(a) Steatoda nobilis are very similar in appearance to Latrodectus hesperus. Explain how this
is an advantage to Steatoda nobilis. Give two details.

[2]
(b) Explain how the binomial names of these two spiders indicate that they are not closely
related.

[2]

(c) State the class of invertebrates that Latrodectus hesperus and Steatoda nobilis are classified
in.

[1]

Cambridge IGCSE
TM
4 Ace Your Biology

Chapter 1.indd 4 30/03/2022 3:07 PM