Biodiversity and Cells PPQs #1

Conservation programmes are used to save endangered species.

The Scottish wildcat, shown in the photograph, is a subspecies of the European wildcat, Felis silvestris silvestris.

The Cairngorms Wildcat Project estimates that there are 150 breeding pairs left, but the Scottish Wildcat Association believes that only 35 cats remain.

A conservation group proposed that a captive breeding programme, and the relocation of Scottish wildcats, would be necessary to prevent extinction.

State why the Scottish Wild cat has been described as endemic.

It is only found in one geographical location

The Scottish Wildcat can interbreed successfully with domestic cats. Explain the effect this could have on the genetic diversity of Scottish Wildcats

Increases size of gene pool

Because of introduction of new alleles into the population

Calculate the index of diversity for lawn A

3.42

Herbicides are sprayed on laws to kill unwanted plants. Explain how the diversity index for lawn A would change if herbicide was used on it.

The value will decrease because there are fewer species present

Muscular dystrophy is a group of disorders that gradually cause muscles to weaken.

One type of muscular dystrophy, caused by a recessive allele, affects 10 people in every 10,000 of the population.

Calculate the number of carriers in a population of 17.02 million.

336,996 carriers

The population of red squirrels on Brownsea island is one of the several protected populations in the UK. Why are these squirrels not classed as endemic?

They are also found in other locations

In 1988, the Kariega Game Reserve in South Africa was farmland.

In 1989, the following species of antelope were reintroduced: impala, blesbok, cape grysbok, bushbuck, duiker, reedbuck and springbok.

The reintroduction of springbok was unsuccessful.

In May 2004, two male and two female lions were released into this game reserve.

Explain why these lions were not released into this game reserve until 2004.

To allow the antelopes time to reproduce

Therefore providing a sustainable food source for the lions

In 1988, the Kariega Game Reserve in South Africa was farmland.

In 1989, the following species of antelope were reintroduced: impala, blesbok, cape grysbok, bushbuck, duiker, reedbuck and springbok.

The reintroduction of springbok was unsuccessful.

In May 2004, two male and two female lions were released into this game reserve.

The two male lions were relocated from one region of South Africa. The females were relocated from a different region of South Africa.

Explain why choosing lions from different regions increased the genetic diversity of the lion population.

Increases chance of mating unrelated lions

Lions will be from different gene pools

Maintain range of alleles in offspring

State what is meant by species richness.

Measure if the number of species in a habitat

State what is meant by the heterozygosity index.

Measure of genetic diversity within a species

Which stage of cell division is shown by cell A?

Anaphase

How are the cells in the image dividing?

Mitosis- to enable growth

Describe how a slide can be prepared from a root tip sample to produce this image.

Cut of end of root cell tip

Stain with toluidine blue

Use HCl to prepare tissue sample, remove tip and stain it, squash with cover slip on slide

Calculate the mitotic index for the cells in this image

23.3%

Deduce the effect of the P21 gene on the cell cycle when cells are treated with gamma radiation.

Radiation can cause damage to chromosomes

Cells with functioning P21 gene show reduced cell division

With faulty P21 gene cell division remains high

Suggests P21 prevents cell progressing through mitosis of DNA damaged

Why is the nucleolus not found in prokaryotic cells?

Prokaryotic cells don’t have a nucleus

Explain why the nucleus cannot be observed at the end of prophase in a eukaryotic cell.

The nuclear membrane is broken down

Because DNA is coiled into individual chromosomes