12. Big mums, big babies

Formative Assessment

Different mammals have different gestation periods. The gestation is time that the foetus is in the womb. For humans it is just under 9 months. Elephants have a gestation period of 22 months and a mouse only 20 days.

Some pupils wanted to find out if the bigger the animal, the longer the gestation period.

They visited the local safari park to find out the mass of some mammals and their gestation period. They chose different animals of different sizes and put the results in the table on the Data Sheet.

Task -

• Using the table and the graph, identify the pattern and describe the relationship between the variables

• Recognise any anomalous (odd) results

• Use scientific ideas to explain your conclusion

• Consider how the evidence could be improved and suggest improvements

You can present your work in any format you choose.

Key words

anomalous result, bar graph, conclusion, data, evidence, improvement, relationship

Table 1

The mass of adult animals and their gestation period.

Graph 1

The relationship between adult mass and gestation period.

The data in Table 2 was collected by doing Internet searches for the largest and oldest animal recorded.

Table 2

Animal records. The biggest and the oldest.

¹ http://news.bbc.co.uk/cbbcnews/hi/newsid_4670000/newsid_4676900/4676904.stm

http://www.myhouserabbit.com/blog/2009/03/07/new-record-holder-for-worlds-oldest- living-rabbit/

² http://www.cat-world.com.au/CatRecords.htm

³ http://www.syracuse.com/news/index.ssf/2008/09/big_norm_the_worlds_largest_bi.html

⁴ http://en.wikipedia.org/wiki/List_of_the_heaviest_people and http://en.wikipedia.org/wiki/Oldest_people

⁵ http://www.wonderquest.com/elephant-ant1-ant2.htm

http://www.metro.co.uk/news/article.html?in_article_id=72621&in_page_id=34