Preliminary Science Competition Biology Grade 9

A plant with variegated leaves was placed in a dark cupboard for 48 hours so that all the starch was removed from the leaves. The variegated leaves have green parts and white parts.

Black paper was then fixed on one leaf and the plant was exposed to the light.

After 24 hours, which region of the leaf contained starch?

• A

• B

• C

• D

1. Which process occurs both in plants and in animals?

• 1. excretion

• 1. phagocytosis

• 1. photosynthesis

• 1. transpiration

3. Which statement about cell structure is correct?

• 1. An animal cell has a cell wall.

• 1. A bacterium has a cell wall.

• 1. An animal cell has chloroplasts.

• 1. A bacterium has chloroplasts.

When the temperature increases, the rate of an enzyme-catalysed reaction increases until the optimum temperature is reached.

Which statement explains why the rate increases?

• 1. The enzyme and substrate have more kinetic energy and collide less frequently.

• 1. The enzyme and substrate have less kinetic energy and collide more frequently.

• 1. The enzyme and substrate have more kinetic energy and collide more frequently.

• 1. The enzyme and substrate have less kinetic energy and collide less frequently

8. What describes the structure of DNA?

• 1. Each strand contains chemicals called fatty acids.

• 1. Each strand contains a sequence of amino acids.

• 1. Each strand contains mRNA.

• 1. Two strands coil to form a double helix.

1. The scientific name for the golden eagle is Aquila chrysaetos. What is the genus of the golden eagle?

• 1. Aquila

• 1. chrysaetos

• 1. eagle

• 1. golden

1. Which row shows structures that are present in both root hair cells and palisade mesophyll cells?

• A

• B

• C

• D

The diagram shows the movement of glucose molecules across a cell membrane.

Which statement describes molecule T?

• 1.  It is a fat molecule used to transport glucose down a concentration gradient.

•  It is a fat molecule used to transport glucose against a concentration gradient.

• It is a protein molecule used to transport glucose down a concentration gradient.

• It is a protein molecule used to transport glucose against a concentration gradient.

6. Which statement about turgor pressure is correct?

• It creates a pull in the xylem which allows water to move upwards.

• It allows sucrose and amino acids to travel upwards and downwards in the phloem.

• 1. It is a pressure that is only found in cells containing chloroplasts.

• 1. It is pressure that helps to provide support for plants

In which diagram would oxygen diffuse into the cell?

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