Topic 1 - Key concepts in biology

Question 1

Name the 4 main sub-cellular structures of animal cells

Answer 1

nucleus, cell membrane, mitochondria, ribosomes

Question 2

Name the 7 main sub-cellular structures of plant cells

Answer 2

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

Question 3

Name the 5 main sub-cellular structures of bacteria

Answer 3

chromosomal DNA, plasmid DNA, cell membrane, ribosomes, flagella

Question 4

What are eukaryotic cells?

Answer 4

Cells with nuclei, including all animal and plant cells

Question 5

What are prokaryotic cells?

Answer 5

Cells without nuclei, e.g. bacteria

Question 6

How does the nucleus relate to its function?

Answer 6

It contains genetic material that controls the activities of the cell

Question 7

What are the functions of the cell membrane?

Answer 7

It holds the cell together and controls what enters and leaves the cell

Question 8

What is the function of mitochondria?

Answer 8

They are where most of the reactions for respiration take place

Question 9

What is the function of ribosomes?

Answer 9

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

Question 10

What is the cell wall made of?

Answer 10

Cellulose

Question 11

What is the function of the cell wall?

Answer 11

It supports the cell and strengthens it

Question 12

What do chloroplasts contain?

Answer 12

A green substance called chlorophyll

Question 13

What is the function of chloroplasts?

Answer 13

They are where photosynthesis occurs

Question 14

What does a large vacuole contain?

Answer 14

Cell sap (a weak solution of sugar and salts)

Question 15

What is the function of the large vacuole?

Answer 15

It maintains the internal pressure to support the cell

Question 16

What is chromosomal DNA?

Answer 16

One long circular chromosome in a bacterium that floats free in the cytoplasm (not in a nucleus)

Question 17

What is the function of chromosomal DNA?

Answer 17

It controls the cell’s activities and replication

Question 18

What is plasmid DNA?

Answer 18

Small loops (plasmids) of extra DNA that aren’t part of the chromosomal DNA (plasmids can be passed between bacteria)

Question 19

What is the flagellum and what are its functions?

Answer 19

A long, hair-like structure that rotates to make the bacterium move.

It can be used to move bacteria away from harmful substances (e.g. toxins) and towards beneficial things (e.g. nutrients, oxygen).

Question 20

In what 4 ways is a sperm cell adapted to its function?

Answer 20

1) Long tail to swim quickly to the egg
2) Lots of mitochondria to provide the energy needed to swim the distance
3) Acrosome at front of the head to store enzymes needed to digest through the membrane of the egg cell
4) Contains a haploid nucleus

Question 21

In what 3 ways is an egg cell adapted to its function?

Answer 21

1) Contains nutrients in the cytoplasm to feed the embryo
2) Contains a haploid nucleus
3) Straight after fertilisation, its membrane changes structure to prevent any more sperm from entering, making sure the offspring have the right amount of DNA

Question 22

In what way is a ciliated epithelial cell adapted to its function?

Answer 22

It has cilia (hair-like structures) on the top of it which beat to move unwanted substances (e.g. mucus) away

Question 23

What is an epithelial cell?

Answer 23

A cell that lines the surface of an organ