Topic 1. Key concepts in Biology.

Question 1

What is the function of the nucleus?

Answer 1

The nucleus contains genetic material that controls the activities of the cell.

Question 2

Function of the cytoplasm?

Answer 2

The cytoplasm is a gel-like substance where most of the chemical reactions happen. It also contains enzymes that control these chemical reactions.

Question 3

Function of the cell membrane?

Answer 3

It holds the cell together and controls what goes in or out.

Question 4

Function of mitochondria?

Answer 4

These are where most of the reactions for respiration take place.

Question 5

Function of ribosomes?

Answer 5

They are involved in translation of genetic material in the synthesis of proteins.

Question 6

Function of the cell wall?

Answer 6

It is made of cellulose and supports the cell and strengthens it.

Question 7

Function of the vacuole?

Answer 7

The vacuole contains cell sap, which is a weak solution of sugar and salts. It maintains the internal pressure to support the cell.

Question 8

Function of chloroplasts?

Answer 8

These are where photosynthesis occurs, making food for the plant. They contain chlorophyll.

Question 9

Function of chromosomal DNA?

Answer 9

It controls the cell’s activities and replication. It floats free in the cytoplasm.

Question 10

Function of plasmid DNA?

Answer 10

Plasmids are extra loops of DNA that aren’t part of the chromosome. They contain genes for things like drug resistance and can be passed between bacteria.

Question 11

Function of flagella?

Answer 11

A flagellum is a long, hair-like structure that rotates to make the bacterium move. It can be used to move the bacteria away from harmful substances like toxins and towards beneficial things like oxygen or nutrients.

Question 12

Subcellular structures in an animal cell? (5)

Answer 12

nucleus, cytoplasm, cell membrane, mitochondria, ribosomes

Question 13

Subcellular structures in a plant cell? (6)

Answer 13

nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, cell wall, vacuole, chloroplasts

Question 14

Subcellular structures in a bacterial cell? (5)

Answer 14

chromosomal DNA, ribosomes, cell membrane, plasmid DNA, flagellum

Question 15

How is an egg cell adapted to it’s function? (3)

Answer 15

It contains nutrients in the cytoplasm to feed the embryo.
It has a haploid nucleus.
Its membrane changes structure to stop any more soerm getting in straight after fertilisation. This makes sure the offspring end up with the right amount of DNA.

Question 16

How is a sperm cell adapted to its function? (4)

Answer 16

A sperm cell has a long tail so it can swim to the egg.
It has lots of mitochondria in the middle section to provide the energy needed to swim the distance.
It has an acrosome at the front of the head, where it stores enzymes needed to digest its way through the membrane of the egg cell.
It contains a haploid nucleus.

Question 17

What is the function of sperm cells?

Answer 17

To transport the male’s DNA to the female’s egg.

Question 18

What is function of an egg cell?

Answer 18

To carry the female DNA and to nourish the developing embryo in the early stages.

Question 19

Why do egg cells and sperm cells both have a haploid nucleus?

Answer 19

Because when an egg and sperm nucleus combine, the resulting cell with have the right no. of chromosomes.

Question 20

What is the function of ciliated epithelial cells?

Answer 20

They move substances.

Question 21

What are cilia?

Answer 21

Hair-like structures

Question 22

What is the purpose of the ciliated epithelial cells that line the airways?

Answer 22

They move mucus and particles from the air up to the throat so it can be swallowed and doesn’t reach the lungs.

Question 23

What does the term ‘haploid’ mean?

Answer 23

A cell containing half the no. of chromosomes that’s in a normal body cell.

Question 24

Give an advantage of electron microscopes over light microscopes.

Answer 24

They have higher magnification and resolution.

Question 25

Why is it necessary to use thin samples of tissue when viewing cells using a light microscope?

Answer 25

Because the specimen needs to let light through.

Question 26

Why might you use a stain when viewing cells using a light microscope?

Answer 26

A stain may make the specimen easier to see and highlight certain structures within cells.

Question 27

Which adjustment knob should you use first when using a light microscope?

Answer 27

Coarse adjustment knob

Question 28

What is the equation you would use to find the size of a specimen using the magnification used and the size of the image seen through a microscope lens?

Answer 28

Real size = image size / magnification

Question 29

How do you convert from mm to um?

Answer 29

Mm — um

x1000

Question 30

Which unit can be expressed in standard form as 10-12m?

Answer 30

Picometre(pm)

Question 31

Which unit can be expressed in standard form as 10-9m?

Answer 31

Nanometre(nm)

Question 32

Which unit can be expressed in standard form as 10-6m?

Answer 32

Micrometre(um)

Question 33

Which unit can be expressed in standard form as 10-3m?

Answer 33

Millimetre(mm)

Question 34

What do carbohydrases do?

Answer 34

They convert carbohydrates into simple sugars.

Question 35

What do proteases do?

Answer 35

Convert proteins into amino acids.

Question 36

What do lipases do?

Answer 36

Convert lipids into glycerol and fatty acids.