Cell Cycle, Mitosis, Meiosis

Question 1

Define cancer

Answer 1

A group of cells that form from abnormal cell division

Question 2

What does cancer result in

Answer 2

-abnormal cell sizes, nuclei, and chromosome numbers
-excessive cell division results in cells piling up to produce tumours

Question 3

Two types of tumours

Answer 3

Benign: non-spreading, less dangerous
Malignant: capable of metastasis and are more dangerous

Question 4

What is the purpose of Meiosis

Answer 4

Cell division that produces non-identical sex cells (gametes) for reproduction

Question 5

What is the purpose of Mitosis

Answer 5

Cell division that produces identical daughter cells for
-growth
-repair
-replacement

Question 6

What are homologous pairs

Answer 6

A pair of chromosomes (one inherited from each parent) that carry genes for the same trait (hair colour)

Question 7

Diploid

Answer 7

Having two full sets of chromosomes (2n)

Question 8

Haploid

Answer 8

Having a single set of chromosomes (n)

Question 9

What is Independent Assortment

Answer 9

The random alignment of maternal and paternal chromosomes at the equator

Question 10

What is Crossing Over

Answer 10

The exchange of segments between homologous pairs of chromosomes

Question 11

When does Crossing Over happen

Answer 11

Prophase (I)

Question 12

When does Independent Assortment happen

Answer 12

Metaphase (I)

Question 13

Denfine gametes

Answer 13

Reproductive cells (sperm or egg)
A.K.A. - germ cells

Question 14

What happens in Prophase (I)

Answer 14

-nuclear envelope dissolves
-spindle fibres form + centrioles move to opposite poles
-chromatin condenses into chromosomes
-homologous chromosomes pair up
crossing over occurs

Question 15

What happens in Metaphase (I)

Answer 15

-homologous pairs line up at the equator
independent assortment occurs

Question 16

What happens in Anaphase (I)

Answer 16

-spindle fibres pull chromosomes to opposite poles

Question 17

What happens in Telophase (I)

Answer 17

-chromosomes lengthen into chromatin
-nuclear envelopes form around each set of chromosomes (23 per cell)
-cleavage furrow forms
-2 haploid cells are formed

Question 18

What happens in Prophase (II)

Answer 18

-nuclear envelopes dissolve
-spindle fibres form + centrioles move to opposite poles
-chromatin condenses into chromosomes

Question 19

What happens in Metaphase (II)

Answer 19

-individual chromosomes line up at the equator

Question 20

Wha happens in Anaphase (II)

Answer 20

-spindle fibres pull chromatids to opposite poles

Question 21

What happens in Telophase (II)

Answer 21

-nuclear envelopes reform around each set of chromosomes (23 per cell)
cleavage furrow forms to make 4 haploid cells that are genetically unique
-spindle fibres dissolve
-chromosomes lengthen into chromatin

Question 22

What is monosomy

Answer 22

Having only one of a homologous pair of chromosomes
E.g. Turner’s Syndrome (XO)

Question 23

What is polysomy

Answer 23

Having an extra copy of a certain chromosome
E.g. Down Syndrome (extra chromosome 21)

Question 24

Examples of Genetic Disorders

Answer 24

-Cystic Fibrosis
-Red-Green Colourblindness
-Down Syndrome

Question 25

Cause and Symptoms of Red-Green Colourblindness

Answer 25

-X-linked recessive trait
-Can’t distinguish between colours red and green

Question 26

Down Syndrome Cause and Symptoms

Answer 26

-3 copies of chromosome 21 due to a non-disjunction in meiosis
-Unique hands, feet, and facial features, metal and physical developmental challenges

Question 27

What is a non-disjunction

Answer 27

The failure of homologous chromosomes to separate during meiosis

Question 28

What is Genetic Screening

Answer 28

Karyotype studies used to determine the risk of inheriting a disorder