DNA structure and function

Question 1

What are the three cell theories?

Answer 1

• All living things must have cells
• New cells come from pre-existing cells
• Cells are the smallest unit of life.

Question 2

What are the two main types of cells?

Answer 2

Eukaryotic and prokaryotic

Question 3

What is a prokaryotic cell? (5)

Answer 3

A bacteria cell.
- It is less complex
- No nucleus
- Unicellular
- No membrane bound organelles

Question 4

What is a eukaryotic cell?

(5)

Answer 4

Animal/plant cell
- Complex
- Nucleus
- Multicellular
- Membrane bound organelles

Question 5

What is a cell membrane

Answer 5

All cells have a cell membrane, it acts as a barrier around the cell

Question 6

What is cytoplasm?

Answer 6

Fluid inside the cell membrane surrounding everything inside.

Question 7

What is DNA?

Answer 7

Genetic information that gives instructions to make proteins for the body. It provides all necessary information to reproduce and construct a new organism.

Question 8

What are Ribosomes?

Answer 8

This is where proteins are synthesised. It takes amino acids and make a genetic chain.

Question 9

How is a trait determined?

Answer 9

Traits are determined by a special molecule called DNA.

Question 10

What is the DNA structure?

Answer 10

DNA is arranged in a double helix.
It is made up of nucleotides.

Question 11

What are nucleotides made up of?

Answer 11

Sugar phosphate backbone and four nucleotide bases.

Question 12

What are genes?

Answer 12

Genes are sections of DNA.
Genes code for proteins that do various jobs around your body.

Question 13

What do both eukaryotic and prokaryotic cells have in common?

Answer 13

• ribosomes
• Cell membrane
• DNA
• Cytoplasm

Question 14

In what order does the body use amino acids as building blocks?

Answer 14

Amino acids
Proteins
Living cells
Tissue
Organs

Question 15

How can we read the genetic code

Answer 15

When you look at half of the DNA molecule

Question 16

How is RNA made?

Answer 16

Chemicals inside the nucleus make partial copies of the DNA code. This is called RNA.

Question 17

What does RNA do?

Answer 17

They move from the nucleus to the cytoplasm to the ribosome, from here the ribosomes create proteins.

Question 18

What is the structure of a chromosome?

Answer 18

The are rolled up strands of DNA

Question 19

Most humans contain a full set of chromosomes how many pairs are there?

Answer 19

23 pairs of chromosomes are in every cell nucleus. With 22 pairs being autosomes and 1 pair being the sex chromosome.

Question 20

What are the chromosomes for the female and male?

Answer 20

Males chromosomes are xy
Female chromosomes are xx

Question 21

What is a mutation?

Answer 21

A mutation is a change in the DNA. This is usually random and can be a result of exposure to mitogens. Mutations are usually permanent. They can either be harmful of beneficial.

Question 22

What causes mutations?

Answer 22

• Errors in the DNA system
• Cell division
• Mutagens

Question 23

What is a spontaneous mutation?

Answer 23

Random mistakes in the normal process of a DNA replication.

Question 24

What is an induced mutation?

Answer 24

A mutation caused by the environment. Such as the impact of radiation. For example the HPV virus increases the risk of cervical cancer.

Question 25

What is the sugar in DNA called

Answer 25

Deoxyribose

Question 26

What are the 4 nitrogenous bases of DNA

Answer 26

Cytosine
Guanine
Adenine
Thyme

Question 27

What nitrogenous bases are complementary?

Answer 27

Adenine and Thyme
Cytosine and Guanine

Question 28

What are Alleles

Answer 28

These are variations of a gene. They code for different versions of the same characteristics. these versions are known as traits.

Question 29

What is a Genotype?

Answer 29

Genotypes are made up of ones allele.
They are traits that get passed to us through hereditary.

Question 30

What is a phenotype?

Answer 30

Is physical traits that we can see. (bleached hair)

Question 31

What does homozygous mean?

Answer 31

Both alleles are the same

Question 32

What does heterozygous mean?

Answer 32

Two different alleles.

Question 33

What is miosis?

Answer 33

Meiosis consists of 5 phases, that occur twice, to produce four haploid daughter cells

Question 34

What happens to the cell during interphase

Answer 34

The cell grows and replicates its DNA

Question 35

What happens to the cell during prophase I

Answer 35

Chromosomes condense and homologous pairs come together to form tetrads. Crossing over may occur, where segments of DNA are exchanged between homologous chromosomes.

Question 36

What happens to the cell during metaphase I

Answer 36

Tetrads line up along the middle and spindle fibres attach

Question 37

What happens to the cell during anaphase I

Answer 37

Homologous chromosomes separate & are pulled to opposite ends of the cell

Question 38

What happens to the cell during Telophase I and Cytokinesis

Answer 38

The cell divides into two daughter cells, each with a diploid set of chromosomes.

Question 39

What happens to the cell during prophase II

Answer 39

Chromosomes recondense and spindle fibres form

Question 40

What does an egg and a sperm make?

Answer 40

Zygote

Question 41

What does a chromosome do?

Answer 41

Chromosomes allow DNA to be accurately copied during these cell divisions.

Question 42

What are gametes?

Answer 42

sex cells