Biology B1 Cells

Question 1

Cells can either be …..

Answer 1

Eukaryotic : Complex e.g. animal and plant cells.

Prokaryotic: Smaller and simpler e.g. bacteria.

Question 2

What are the functions of:

• Nucleus
• Cytoplasm
• Mitochondria
• Ribosomes

Answer 2

Nucleus: Contains genetic material that controls the activities of the cell.

Cytoplasm: Gel like substance where most chemical reactions happen. Contains enzymes.

Mitochondria: Where most of the reactions for respiration take place. Respiration transfers energy.

Ribosomes: Involved in translation of genetic material in the synthesis of proteins.

Question 3

What subcellular structures does a bacteria have and what are their uses.

Answer 3

Chromosomal DNA: controls the cell activities.
Ribosomes:
Cell membrane:
Plasmid DNA: Extra DNA that, plasmid contains genes for drug resistance and this can be passed between bacteria.
Flagellum: A long hair like structure that helps the bacterium to move. Bacteria can move away from harmful toxins and move towards nutrients and oxygen.

Question 4

What happens during Sexual Reproduction.

Answer 4

The nucleus of an egg cell fuses with the nucleus of a sperm cell to create a fertilised egg, which develops into an embryo.

Question 5

Describe the adaptations of an Egg cell.

Answer 5

1) Contains nutrients in the cytoplasm to feed the embryo.
2) After fertilisation, its membrane changes structure to stop more sperm getting in.
3) Haploid Nucleus

Question 6

Describe the adaptations of a Sperm cell.

Answer 6

1) A sperm cell has a long tail so it can swim to the egg.
2) It has lots of mitochondria in the middle section to provide the energy needed to swim this distance.
3) 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.
4) Haploid Nucleus.

Question 7

Describe the functions of Ciliated Epithelial Cells.

Answer 7

Moves substances

E.G. it helps move mucus up the throat so it can be swallowed and doesn’t reach the lungs.