MGD S4 - DNA replication, Cell division and Inheritance Flashcards Preview

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Flashcards in MGD S4 - DNA replication, Cell division and Inheritance Deck (24):
1

What is the role of the cell cycle?

Mitosis division used in growth and repair
Contains several key checkpoints to prevent improper cell division

1

What are the stages of the cell cycle? (Names only)

G1
S
G2
Mitosis

3

What's occurring during S phase of the cell cycle?

Chromosomes duplicate to form classical X shape (2 chromatids)

3

At happens in G1 phase of the cell cycle?

Cellular content replication

4

What happens during G2 phase of the cell cycle?

DNA is checked for errors and corrected

4

At happens during the mitosis phase of the cell cycle?

The cell divides creating two genetically identical daughter cells.

5

Define genotype

The genetic makeup of an individual
Can also refer to a specific genetic loci

5

Define phenotype

All observable expressed traits as a result of genotype
Can also refer a specific trait arising from a single genetic loci

6

Are gametes haploid or diploid?

Haploid

6

What environmental factors may affect genotype and phenotype?

Radiation
Mutagens
Chemicals that affect cell growth
Diet Lifestyle (phenotype only)
Trauma (phenotype only)

7

How does meiosis I differ from mitosis?

Instead of lining up along the equator single file, they line up in homologous pairs and are split into two sets of full (2 chromatids) chromosomes.

8

What sort of genetic disease affects 25% of two carriers offspring?
Give an example

Autosomal recessive
Cystic fibrosis

8

Name the three types of sex linked inheritance.

X linked dominan
tX linked recessive
Y linked

9

Define the term 'allele'

Refers to the different forms of a gene. Every individual has two alleles of the same gene, can either be the same or different.

10

Define the term 'gene'

A unit of heredity, length of DNA that codes for a protein as well as the necessary sequences for it's expression such as promoter and terminator sequences and introns

10

What is autosomal inheritance?

Inheritance of a gene on a non sex linked chromosome (autosome)

11

What is meant by co-dominance in reference to alleles/traits?
Give an example of co-dominance

Both alleles are expressed in the phenotypic trait of heterozygotes.
Eg. AB blood type

11

Explain the basis of co-inheritance of genes.

Genes on the same chromosome are likely to be inherited together
However the process of crossing over in meiosis will separate genes previously on the same chromosome.
Additionally, genes located close to one another on the same chromosome are said to be LINKED, less likely to be separated in crossing over.
Genes further away from each other more likely to be separated. Behave almost like unlinked.

12

What sort of genetic disease effects one person of every generation?
Give an example.

Autosomal dominant
Marfan's syndrome

14

What is sex linked inheritance?

Inheritance of a gene on the X or Y chromosome

15

Haemophilia is an example of what type of genetic disease?

X linked recessive

15

What sort of genetic disease only affects males?

Y linked, passed from father to son.

16

Explain what is meant by 'dominance' of an allele/trait.

The phenotypic trait is expressed in homozygotes and heterozygotes

16

Explain what is meant by the term 'recessive' for alleles/traits.

Phenotypic trait appears only in homozygotes